Dissertations / Theses: 'Boreholes'

1

Dunn, Paul Gregory. "Fluid drainage into boreholes within coal seams /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17776.pdf.

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2

Zhou, Tiepeng. "Seismic wave propagation in and around boreholes." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/58056.

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3

Hughes, Simon. "Geohydrology data model design : South African boreholes." Thesis, Stellenbosch : University of Stellenbosch, 2005. http://hdl.handle.net/10019.1/2799.

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Thesis (MSc (Geography and Environmental Studies))--University of Stellenbosch, 2005.
Since mechanised borehole drilling began in South Africa in the late 1800s, over 1 100 000 boreholes have been drilled. As the country’s growing population and the perceived impacts of climate change increase pressure on water surface supplies, attention is turning to groundwater to meet the shortfall in water supply. This will mean even more drilling will take place. Until the introduction of the Standard Descriptors for Boreholes, published in 2003, South Africa has not had a set of guidelines for borehole information capture. This document provides a detailed description of the basic information requirements needed to describe and characterise the process of drilling, constructing, developing, managing and monitoring a borehole. However, this document stands alone as a specification with little or no implementation or interpretation to date. Following the development and publishing of the ArcHydro data model for water resource management by the CRWR based at the University of Texas at Austin, there has been a great deal of interest in object-oriented data modelling for natural resource data management. This thesis describes the utilisation of an object oriented data modelling approach using UML CASE tools to design a data model for South African Boreholes, based on the Standard Descriptors for Boreholes. The data model was converted to a geodatabase schema and implemented in ArcGIS.

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4

Sizer, Calvin Gregory. "Minor actinide waste disposal in deep geological boreholes." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/41595.

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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2006.
Includes bibliographical references (leaves 63-65).
The purpose of this investigation was to evaluate a waste canister design suitable for the disposal of vitrified minor actinide waste in deep geological boreholes using conventional oil/gas/geothermal drilling technology. The nature of minor actinide waste was considered, paying particular attention to nuclides whose decay energy and half lives were of relative significance to the minor actinide waste as a whole. Thermal Analysis was performed based on a reference borehole design, by Ian C. Hoag. The strategy of the thermal analysis is aimed at finding peak temperatures within the configuration, paying particular attention to the heat transfer under deep geological conditions in the air gap between the canister and the borehole. A first order economic analysis was made to compare the designed canister emplacement costs to that of intact spent fuel. The results of this analysis show that three minor actinide nuclides dominate heat generation after ten years cooling: Cm-244, Am-241, and Am-243 account for 97.5% of minor actinide decay heat. These three nuclides plus Np-237 account for 99% of the minor actinide mass. The thermal analysis was based on an irretrievable canister design, consisting of a 5 meter long synroc waste form, with minor actinides loaded to 1% wt, an outer radius of 15.8 cm and inner annular radius of 8.5 cm. Filling the annulus with a vitrified technetium and iodine waste form was found to be feasible using a multi-stage emplacement process. This process would only be required for three of the fifty boreholes because technetium and iodine have low heat generations after 10 years cooling. The suggested borehole waste form has a maximum centerline temperature of 349C. The costs of drilling boreholes to meet the demand of 100,000MT of PWR waste are estimated to be 3.5% of the current nuclear waste fund, or about $9.6/kg of original spent fuel.
by Calvin Gregory Sizer.
S.B.

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5

Lee, Hyun Yup. "Drillstring axial vibration and wave propagation in boreholes." Thesis, Massachusetts Institute of Technology, 1991. http://hdl.handle.net/1721.1/13907.

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6

Rama, Rao V. N. "Acoustic transmission through fluid-filled pipes in boreholes." Thesis, Massachusetts Institute of Technology, 1991. http://hdl.handle.net/1721.1/13427.

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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1991, and Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1991.
by Rama Rao V.N.
M.S.

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7

Fallahzadeh, Abarghooei Syed Hassan. "Simulations of hydraulic fracturing initiation in perforated boreholes." Thesis, Curtin University, 2015. http://hdl.handle.net/20.500.11937/1332.

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The mechanism of initiation and propagation of hydraulic fracture from cased hole perforated wellbores is investigated through analytical, numerical and experimental studies. A new model was developed for arbitrarily oriented wellbore and perforation to predict the fracture initiation pressure, location and orientation, along the perforation length. In addition, scaled experimental and numerical studies were carried out to validate the analytical model and to investigate the effects of fluid viscosity and injection rate on fracture geometry.

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8

Appleby, Susan. "Macroscopic stress analysis and microscopic continuum modelling for porous and non porous elastic solids." Thesis, Imperial College London, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284319.

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9

Adaiem, Miloud H. "Wellbore integrity in shale strata." Thesis, University of Aberdeen, 2010. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=165843.

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Air drilling is limited to competent formations that are essentially dry. In these circumstances large shale fragments are often observed and it is believed that these large shale fragments are not from the cutting action of drill bit at the bottom of the hole but from caving in, or sloughing of the wellbore wall. This type of wellbore instability problems may occur when drilling formations have significant amounts of water-sensitive clays. Change in shale water content due to water dehydration induces additional rock stresses near the wellbore, which can destabilize the borehole. The primary cause of this problem may well relate to moisture movement. Because as air is often used as the drilling fluid, the water in exposed pores will start to evaporate into the borehole, so that the water content is reduced. This results in the development of different stress patterns and the shale fractures and falls into the wellbore. The work of this thesis simulates the shrinkage and the consequent cracking pattern. A model of a bonded granular material is created and its properties confirm it to be that of a brittle, isotropic elastic solid. Crack growth is simulated by sequentially removing the most highly stressed bond in turn. A number of different geometries are simulated and the influence of stochastic bond strength on the cracking pattern is investigated. The model results show that cracking pattern produced in the simulations is consistent with the ‘blocky’ debris sometimes seen during air drilling and so the recommendation is made that air used for drilling should be sufficiently humid to avoid the dehydration of the shale.

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10

Long, P. J. G. "Experimental studies of fluid-fluid displacement in annuli." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386649.

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11

Wang, Zhihua. "A simulation study for gas kicks in deviated and horizontal boreholes." Thesis, Heriot-Watt University, 1994. http://hdl.handle.net/10399/1366.

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12

Rao, V. N. Rama. "The radiation and vibration of drilling tubulars in fluid-filled boreholes." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/11277.

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13

Bates, Ethan Allen. "Optimization of deep boreholes for disposal of high-level nuclear waste." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/97968.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 223-240).
This work advances the concept of deep borehole disposal (DBD), where spent nuclear fuel (SNF) is isolated at depths of several km in basement rock. Improvements to the engineered components of the DBD concept (e.g., plug, canister, and fill materials) are presented. Reference site parameters and models for radionuclide transport, dose, and cost are developed and coupled to optimize DBD design. A conservative and analytical representation of thermal expansion flow gives vertical velocities of fluids vs. time (and the results are compared against numerical models). When fluid breakthrough occurs rapidly, the chemical transport model is necessary to calculate radionuclide concentrations along the flow path to the surface. The model derived here incorporates conservative assumptions, including instantaneous dissolution of the SNF, high solubility, low sorption, no aquifer or isotopic dilution, and a host rock matrix that is saturated (at a steady state profile) for each radionuclide. For radionuclides that do not decay rapidly, sorb, or reach solubility limitations (e.g., 1-129), molecular diffusion in the host rock (transverse to the flow path) is the primary loss mechanism. The first design basis failure mode (DB 1) assumes the primary flow path is a 1.2 m diameter region with 100x higher permeability than the surrounding rock, while DB2 assumes a 0.1 mm diameter fracture. For the limiting design basis (DB 1), borehole repository design is constrained (via dose limits) by the areal loading of SNF (MTHM/km2 ), which increases linearly with disposal depth. In the final portion of the thesis, total costs (including drilling, site characterization, and emplacement) are minimized ($/kgHM) while borehole depth, disposal zone length, and borehole spacing are varied subject to the performance (maximum dose) constraint. Accounting for a large uncertainty in costs, the optimal design generally lies at the minimum specified disposal depth (assumed to be 1200 in), with disposal zone length of 800-1500 m and borehole spacing of 250-360 meters. Optimized costs range between $45 to $191/kgHM, largely depending on the assumed emplacement method and drilling cost. The best estimate (currently achievable), minimum cost is $134/kgHM, which corresponds to a disposal zone length of -900 meters and borehole spacing of 272 meters.
by Ethan Allen Bates.
Ph. D.

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14

De, Wet Neil. "Towards a model for environmental assessment and management of boreholes in communal areas in Namibia." Master's thesis, University of Cape Town, 1997. http://hdl.handle.net/11427/18370.

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This was the final statement in a report, prepared for the Namibian Programme to Combat Desertification (NAPCOD), which researched the process, praxis and environmental impacts of borehole provision in communal areas in Namibia (ENGEO, 1997).¹ This dissertation is a response to this concluding statement. It presents a theoretical model which provides a comprehensive yet simple environmental assessment and management framework to inform, guide and manage the provision of boreholes in communal areas in Namibia. The model has been designed to be cost effective, appropriate for its context and 'user-friendly'. Most importantly, the model aims to present a system which would promote principles of sustainability and, consequently, sustainable development in terms of borehole provision in communal areas in Namibia.

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15

Anderson, Victoria Katherine 1980. "An evaluation of the feasibility of disposal of nuclear waste in very deep boreholes." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/33638.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 2004.
Includes bibliographical references (leaves 117-119).
Deep boreholes, 3 to 5 km into igneous rock, such as granite, are evaluated for next- generation repository use in the disposal of spent nuclear fuel and other high level waste. The primary focus is on the stability and solubility of waste species, waste forms, and canister materials in saline, anoxic water, which is the most severe potential downhole environment given the sparse data available. Pourbaix (Eh-pH) diagrams and solubility products were calculated for 20 materials of interest. In general, extremely low dissolved concentrations were estimated. Copper was identified as the best canister material. Wall-to-far-field temperature increases were estimated to be about 20⁰ C for canisters containing two PWR assemblies, which is quite tolerable. Aspects requiring further work in the near term are detailed canister interior design to withstand crushing under a 1 km stack of same, and development of a borehole plug concept having a comparable or better impermeability and radionuclide holdup than the surrounding granite bedrock.
by Victoria Katherine Anderson.
S.M.

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16

Macgregor, Kenneth Waddell. "An investigation into the induced state of stress around inclined boreholes under non-hydrostatic stress conditions." Thesis, University of Strathclyde, 1987. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21493.

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This thesis details research conducted towards investigating the state of stress around inclined boreholes with the ultimate aim of predicting borehole stability and providing realistic estimates of closure stress. Chapter 1 discusses the factors affecting the stability of boreholes and reviews previous research conducted into borehole failure. The mechanics of hydraulic fracturing are reviewed as are methods of predicting fracture gradients. The manner in which closure stress is estimated is also critically reviewed. Chapter 2 describes an initial investigation into the stresses around inclined boreholes using the photoelastic technique of Stress Freezing. Chapter 3 details the laboratory determination of rock properties required for the borehole stability work detailed in Chapter 4. The applicability of the Brinell Hardness test to rock is also examined. Chapter 4 presents a detailed analysis of borehole stability. Failure criteria are developed and applied to estimate the mud weight required to maintain the hole in an elastic condition. To investigate the post-failure stability, existing 'yield zone' equations are modified to allow the effect of rock strength, oil flow rate, in-situ stress and hole angle to be examined. Chapter 5 describes the design and in-house manufacture of the specialised equipment required to measure fracture conductivity in the laboratory, the development of experimental procedures, the various test results and the conclusions drawn from them. Finally, the direct effect of a yield zone on the estimation of closure stress and on proppant selection is examined Chapter 6 summarises the conclusions that may be drawn from the work detailed in this thesis. The chapter also describes possible fields of future research which have been stimulated by the work presented. Two appendices are included, one providing a data-base of proppant properties, the other detailing the results of the application of the data-base to formation samples.

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17

Ramstad, Randi Kalskin. "Ground source energy in crystalline bedrock - increased energy extraction by using hydraulic fracturing in boreholes." Doctoral thesis, Norwegian University of Science and Technology, Department of Geology and Mineral Resources Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-496.

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The use of improved equipment and methodology can result in considerable reductions in the drilling costs for medium- to large sized ground source heat pump system in crystalline bedrock. The main point has been to use special techniques within hydraulic fracturing to create a larger heat exchange area in the bedrock, and thus a greater energy extraction per borehole. The energy extraction is based on circulating groundwater.

Stimulation with hydraulic fracturing is a well known technique in order to improve borehole yields for drinking water-, oil-, and geothermal purposes. A procedure for injection of propping agents in selected borehole sections, and custom-made equipment for hydraulic fracturing in crystalline bedrock, a double packer, have been developed in this study. The propping agents are likely to ensure a permanent improvement of the hydraulic conductivity in a long-run perspective.

In addition to a pre-test, a comprehensive test programme has been performed at each of the two pilot plants at Bryn and at the former property of Energiselskapet Asker og Bærum (EAB) in Bærum municipality outside Oslo, Norway. A total of 125 stimulations with hydraulic fracturing using water-only and hydraulic fracturing with injection of sand have been performed in 9 boreholes. Test pumping and geophysical logging (temperature, electrical conductivity, gamma radiation, optical televiewer and flow measurements) have been carried out in order to document the effect of the hydraulic fracturing.

The pilot plants at Bryn and EAB, where the ground source heat pump systems are based on circulating groundwater, have demonstrated the short-period energy extraction, limitations and opportunities of the concept for hydraulic fracturing and increased energy extraction in different geological and hydrogeological areas. The bedrock at Bryn and EAB is characterized as a low-metamorphic sandstone and a nodular limestone, respectively. At Bryn, the five boreholes were organised with a central borehole encircled by four satellite boreholes 13 metres away from the central borehole. The central borehole at EAB was flanked with two boreholes 16 and 20 metres away. In operation mode, groundwater was pumped from the satellite boreholes, heat exchanged, and re-injected into the groundwater magazine via the central borehole. Routine operation of the plants has not yet been initiated.

The main findings from this study can be summarized as follows:

•Hydraulic fracturing with water-only results in an overall increase in water yield for the hard rock borehole.

•Hydraulic fracturing with injection of sand as propping agent also leads to an increased water yield.

•The use of sand as propping agent seems to be more required in fractures with high counter pressure, in this study higher than approximately 40 bars, compared with fractures with lower counter pressure. The particle size of the sand should also be adjusted to the appearing counter pressure, and injection of coarser sand is recommended in fractures with lower counter pressures.

•Comparing the results from the hydraulic fracturing performed at Bryn and EAB shows that the pressure levels, required to create new fractures, varied considerably. The maximum pressures present at Bryn were higher than the corresponding pressures at EAB. At Bryn 70% (44 out of 63) of the pressure-time curves from the hydraulic fracturing with water-only were interpreted as initiation or reopening of fractures, while the number for EAB was 97% (36 out of 37). The lower degree of fracturing at Bryn is likely to be a result of high rock stresses and high tensile strength of the bedrock, also confirmed by the results from the rock stress measurements performed at Bryn. Considering the bedrock at EAB, characterized as nodular limestone, the tensile strength is assumed to be less than the values for the low-metamorphic sandstone present at Bryn.

•The infiltration rate in the central boreholes is a critical factor for the energy extraction and a successful operation of ground source heat pump systems based on circulating groundwater. Results from the short-period circulation tests accomplished at Bryn and EAB show that the infiltration rate in the central borehole at Bryn (approximately 2500 litres/hour) was too low to obtain a satisfactory operation of the plant, while the infiltration rate at EAB (14000 litres/hour) was sufficient to achieve profitability. Under the actual conditions, a reduction in the construction costs, i.e. the drilling costs, for a conventional ground source heat pump system with single U-collectors in vertical boreholes, of more than 50% were achieved for the pilot plant at EAB when the energy extraction from water is more than 105 MWh. The large difference in the infiltration rate between Bryn and EAB was probably related to: (1) Large initial differences in the borehole yield prior to hydraulic fracturing (<560 litres/hour at Bryn and >6300 litres/hour at EAB). Nodular limestone generally has high permeability, while compact sandstone rocks are expected to have low permeability. (2) Hydraulic fracturing was most successful at EAB. (3) The higher rock stress level present at Bryn compared to EAB will increase the tendency to tighten the opened fractures, even the fractures with injected sand •The FEFLOW-modelling of the pilot plant at Bryn and EAB emphasized the important relation between the available heat exchange area in the bedrock, the thermal conductivity of the bedrock, and the energy potential.

•The increased borehole yields achieved by hydraulic fracturing in this study, and the improved, reliable and cost-effective hydraulic fracturing techniques in crystalline bedrock, will probably increase the interest for groundwater as a domestic water supply for small- to medium sized water works.

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18

Sharif, Ladan Karimi. "Application of the cross-hole radio imaging method in dectecting geological anomalies, MacLennan township, Sudbury Ontario." Thesis, Laurentian University of Sudbury, 2013. https://zone.biblio.laurentian.ca/dspace/handle/10219/2121.

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The occurrence of conductive sulphide in an otherwise highly-resistive host rock is the ideal situation for exploring using high-frequency electromagnetic methods. The FARA radio imaging (RIM) system was deployed to explore the rock properties between two boreholes MAC104 and MAC100G, which are about 182 m apart, on the Nickel Rim South property (MacLennan Township) 22 km northeast of Sudbury. Tomographic data were collected and processed at 625 kHz and 1250 kHz. One data set has the transmitter in MAC100G and the receiver in MAC104; the other “reciprocal” data set has the transmitter in MAC104 and the receiver in MAC100G. The amplitude data were reduced, edited, and processed to generate tomograms employing the SIRT algorithm. Separate tomograms were created for the reciprocal data sets in the ImageWin software. A sensitivity analysis was conducted to assess the influence that perturbations in the ImageWin processing parameters have on the resulting tomograms. The sensitivity study of the tomograms along with the information obtained from the value of fit analysis can be used to select appropriate processing parameters. Finally, the two reciprocal sets of conductivity values were averaged and imported into Geosoft to create a final tomogram for the panel. The resistivity values of the studied zone obtained from the FARA modeling package agree fairly well with the conductivity data set generated by the ImageWin modeling package when compared using the Geosoft and GOCAD visualization software. Differences between the two tomograms are attributed to the different solver methods employed by FARA and ImageWin and the statistical analysis used for averaging the attenuation value over ray paths. Furthermore, it is shown that the tomographic results are consistent with the location of conductive zones that were identified using down-hole geophysical logging. The main focus of the project is to understand how the radio imaging (RIM) data is processed with the ImageWin software to construct an attenuation tomogram. This research showed that both tomograms created by ImageWin and FARA illustrate the same pattern with two conductive zones at the same depth; however, the values of conductivity are slightly different. The FARA resistivity values obtained for the upper zone is a factor of two lower than the resistivity calculated by ImageWin. The resistivity values obtained for the lower zone using the FARA processing is a factor of eight lower than the resistivity calculated by ImageWin. Also, there is a slight discrepancy in the orientation of the upper and lower zones on the two tomographic images generated using the two processing packages. In the tomograms generated by FARA software both upper and lower zones are continuous linear zones from one hole to the other with dips from MAC104 towards MAC100G, whereas in the tomograms created by ImageWin the upper and lower zones are less linear and do not have obvious dips.

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19

Lingwanda, Mwajuma. "In-situ Penetration as Alternative to Extensive Boreholes and Lab Testing for Exploration in Sandy Soils." Licentiate thesis, KTH, Jord- och bergmekanik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-161217.

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20

Nguyen, Khac Hoang. "Sezónní akumulátor tepla." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417854.

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The aim of the thesis to explain the functionality of seasonal accumulation with an in-depth view on rock bed accumulator. The computational model is based on the project located in Attenkirchen, Germany. After the technical analysis of the model is carried out an economical review can be realized. To conclude the thesis an evaluation is made comparing an accumulation system with a more traditional one.

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21

Smith, Meris. "Prediction, control and rehabilitation of iron encrustation in water supply boreholes, Western Cape, South Africa : a geochemical approach." Doctoral thesis, University of Cape Town, 2006. http://hdl.handle.net/11427/4223.

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22

Moulton, Taylor Allen. "Parametric study of the total system life cycle cost of an alternate nuclear waste management strategy using deep boreholes." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/55071.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2008.
Cataloged from PDF version of thesis.
Includes bibliographical references.
The Department of Energy recently submitted a license application for the Yucca Mountain repository to the Nuclear Regulatory Commission, yet even the most optimistic timetable projects that the repository will not now open until at least 2020. The Office of Civilian Radioactive Waste Management recently revised the official undiscounted total life cycle cost of the waste management system upward by $22B (2000$), an increase of nearly 40% over the previous estimate, published in 2001. In this thesis a waste management tool, named SNuFManager (Spent Nuclear Fuel Manager), has been developed which deterministically simulates the stocks and flows of spent fuel in the United States and estimates annual expenditures based on the system's behavior. The tool allows policy makers to quickly and cheaply estimate the economic consequences of various decision alternatives under an array of scenarios in order to make quantitatively informed decisions and identify ways to mitigate or reverse recent increases in life cycle costs. The results are expressed in 2000 dollars, enabling a convenient comparison with the government's 2001 total system life cycle cost analysis. For each year of delay beyond 2020 in opening the repository and transferring ownership of spent fuel to the federal government, the total waste management system life cycle cost is estimated to increase by another $330M (2000$). The model also estimates that switching from the current mined geologic repository approach to a deep borehole disposal strategy would reduce the undiscounted total system life cycle cost by $19.4B, or 32%.
(cont.) Assuming a 10% discount rate, the net present cost of the deep borehole strategy is 18% less than that of the mined geologic repository approach. Finally, the model illustrates the economic benefits of opening a centralized interim storage facility of significant capacity as soon as possible. For example, if a 40,000 metric tonne facility, comparable in scale to the proposed Private Fuel Storage Facility in Utah, was opened by 2020, and the mined repository was opened in the same year, the total life cycle cost would be reduced by $1.5B relative to the case with no interim storage. If, moreover, the opening date of the mined geologic repository were delayed until 2040 or 2060, the savings provided by interim storage increase dramatically, to $4.9 and $8.1B, respectively. The thesis concludes with a discussion of the political and strategic consequences of several key policy choices.
by Taylor Allen Moulton.
S.M.

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23

Moleele, Nkobi Mpho, and n/a. "Ecological change and piospheres : can the classical range succession model and its modifications explain changes in vegetation and soil around boreholes in eastern Botswana?" University of Canberra. Resource, Environmental & Heritage Science, 1994. http://erl.canberra.edu.au./public/adt-AUC20061018.144247.

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There is concern that the communal rangelands of Botswana are overstocked with cattle, and that this has led to unwanted ecological changes. These changes are assumed to be most prominent around boreholes. This study describes vegetation and soil piospheres around boreholes in Eastern Botswana and investigates factors associated with their development. The classical range succession model and its modifications, the bush encroachment theories and the soil-nutrient transfer model, have been applied here to explain changes in vegetation and soil variables with distance from artificial water points. Data on soil texture, soil nutrients, vegetation species composition and cover, dung weight and bare ground were collected from boreholes of different ages, with different numbers of cattle using them. Piosphere patterns were observed. However, some of the patterns were not in accordance with the classical range succession model and the bush encroachment theories. The frequent occurrence of palatable grasses (Panicum maximum, Setaria verticiliata and Digitaria milanjiand) nearer to water points where the grazing pressure is highest, and of unpalatable ones (Aristida congesta and Eragrostis rigidior) further away, where the grazing pressure is minimal, contradicts the classical range succession model. Total tree cover along the gradient did not show any changes, which contradicts bush encroachment theory (two-layer soil moisture model). The concentration of soil nutrients and dung weight close to boreholes was well predicted by the soil-nutrient transfer model. The frequency of Acacia tortilis and Dicrostachys cinerea and bare patches, increased towards boreholes. Grass cover, occurrence of Terminalia sericea, Boscia albitrunca and Combretum apiculatum increased with distance from water points. The results suggest that the range succession model and its modification, the twolayer soil moisture model, cannot satisfactorily explain vegetation changes with distance from water points. Species composition at a point may be affected by the growth, survival, recovery and reproductive strategies of different species, fire, selectivity of browsers and nutrients status, as well as grazing disturbance. Therefore, the 'state and transition' model is recommended, as it considers factors that are ignored by the classical range succession model, and is appropriate for analysing vegetation change under highly variable rainfall. The adverse impacts of grazing around boreholes could be reduced by controlling cattle distribution on the range as a whole.

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Карінцев, Іван Борисович, Иван Борисович Каринцев, Ivan Borysovych Karintsev, and А. А. Жулев. "Влияние эксцентричности на напряженное состояние кольца скважины." Thesis, Сумский государственный университет, 2013. http://essuir.sumdu.edu.ua/handle/123456789/31846.

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В данной работе рассматривается влияние эксцентричности кольца на распределение напряжений. Проводится сравнение распределения напряжений радиальных и окружных напряжений в эксцентричном и концентричном кольце. При цитировании документа, используйте ссылку http://essuir.sumdu.edu.ua/handle/123456789/31846

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25

Kauppinen, Robin. "Analysis of building energy use and evaluation of long-term borehole storage temperature : Study of the new ferry terminal at Värtahamnen, Sweden." Thesis, KTH, Tillämpad termodynamik och kylteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-174136.

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In 2013, Stockholms Hamnar began a development project for Värtahamnen, one of Stockholms most important harbors, and also decided to build a new ferry terminal that is better suited to meet the increasing capacity demand. The new terminal will feature a borehole storage that will be used to cover the building’s heating and cooling demands. The boreholes have already been drilled and currently the construction of the building is being planned. The overall objective of this project is to study the new terminal and its borehole storage regarding certain input parameters (such as internal heat gains and the U-value of windows) that affect the building’s annual heating and cooling demands, as well as long-term temperature of the borehole storage. To do this, two modeling programs are used: IDA ICE and EED (Earth Energy Designer). The project focuses on three main parts. Part one is a sensitivity analysis of internal loads and construction specific parameters that shows how a variation in these affects the heating and cooling demands. To accomplish this, several models are created and simulated in IDA ICE. In part two, the long-term ground temperature is studied for two of the models analyzed in part one. This is done in both IDA (through a new borehole module) and EED, followed by a comparison of these results. The last part presents the possible amount of free cooling that can be taken from the ground. This estimation is made through simulations in EED, using altered load profiles of the two previously mentioned models. Additionally, this part covers the effects of a changed borehole configuration (number of boreholes, depth, layout, etc.). The results of the first part (the sensitivity analysis) show that there is a rather large variation in annual heating and cooling demands depending on what approach is used for estimating a reasonable amount of internal loads. One way to do this is to first determine the maximum possible load in each zone and then, when simulating the annual energy demand, reduce the total load in the whole building by a certain factor. Another approach is to, from the start of the building modeling, more accurately try to estimate the average amount of internal loads in each zone. In the second part, due to unbalanced load profiles for both analyzed models, the temperature of the borehole storage will increase over time if there is no limitation of the amount of cooling taken from the ground. The results of IDA generally agree with those of EED. In the last part of the project it is shown that a thermally more favorable borehole installation could increase the relative amount of free cooling from the ground, compared to the current installation.

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Kalinski, Michael E. "Determination of in situ V[subscript s] and G[subscript max] using surface wave measurements in cased and uncased boreholes /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.

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27

Gajree, Meenu. "Characterisation of groundwater in mainly old and closed landfill sites." Thesis, Brunel University, 1999. http://bura.brunel.ac.uk/handle/2438/5346.

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A study is made of the use of chemical analysis of groundwater samples to assess groundwater quality. Samples from forty-seven boreholes within and around ten landfill sites in the London Borough of Hounslow were analysed. Most of the landfill sites studied were filled prior to the implementation of the Control of Pollution Act 1974 and were not designed with environmental protection in mind. Boreholes were tested for methane, carbon dioxide and groundwater samples were analysed for electrical conductivity (EC), ammonium nitrogen (NI14-N), COD, TOC, Cl-, NO3, SO42-, Na+, K+, Ca2+, Ni2+, Cu2+, Pb2+, oxidation - reduction - potential (ORP) and pH. The first ten of these analytical parameters were considered for groundwater quality assessment and the most important selected for more detailed study namely CH4, C02, EC, NH4-N, COD and TOC. Pollution ratings are allocated on the basis of single pollutant analytical data and averaged for each of the bore hole samples. Goodness of fit values between the single analyte values and the average data were calculated and no set of single analyte data was found to provide good groundwater quality assessment. A series of formulae combining the six analyte parameters was considered and the data evaluated by goodness of fit calculations to provide an effective means of assessing groundwater quality. The ratings obtained from the best formula are compared with historical broad band classification of landfill sites and show how sites must be assessed on the basis of samples taken from within the site and not around the perimeter. The production of acetic acid in the acetogenic phase of landfill reactions will increase the leachability and mobility of many metal pollutants and particularly of lead. Studies on the leachability of lead in acetic acid media show how lead solubility is increased in acetic acid media by the formation of triacetatolead(II) species, Pb(CH3CO2)3-.

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Ronczka, Mathias [Verfasser], Thomas [Akademischer Betreuer] Günther, Ugur [Gutachter] Yaramanci, and Andrew [Gutachter] Binley. "Saltwater detection and monitoring using metal cased boreholes as long electrodes / Mathias Ronczka ; Gutachter: Ugur Yaramanci, Andrew Binley ; Betreuer: Thomas Günther." Berlin : Technische Universität Berlin, 2016. http://d-nb.info/1156181054/34.

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Mkuu, Doreen Eunice. "Palynological, palynofacies, thermal maturity and burial modelling analyses of the Cretaceous to Cenozoic sediments from a series of Tanzanian onshore and offshore boreholes." Thesis, University of Southampton, 2018. https://eprints.soton.ac.uk/421110/.

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Tanzania is one of the East African countries where rich hydrocarbon accumulations are starting to be discovered in both onshore and offshore sedimentary basins, although there is currently little research that has been published in relevant research areas of geology, micropalaeontology or hydrocarbon prospectivity. The hydrocarbon reserves discovered so far are mainly gas, and these have been found in Cretaceous and Cenozoic reservoirs that provide signatures of multi-source rock origins that demonstrate promising future prospects. This thesis presents a series of studies focussing on improving our understanding of the (bio)stratigraphy and hydrocarbon source rock potential of Cretaceous-Cenozoic sediments of Tanzania. The samples studied have unfortunately yielded impoverished organic-walled microfossil (palynomorph) assemblages, and thus the biostratigraphic analysis has formed a smaller component of this project than originally intended. The main aspect of the research undertaken has thus focussed on analysing organic matter composition (palynofacies analysis) and quality (organic richness, kerogen typing), in order to provide interpretations of the palaeoenvironmental conditions prevailing at the time of sediment deposition and hydrocarbon source potential. The hydrocarbon potential has also been examined by undertaking assessments of the thermal maturity of the host sediments using vitrinite reflectance measurements in order to construct thermal histories and burial models for the several of the study locations. This study examines three hundred Cretaceous-Palaeogene cutting samples from three boreholes drilled on the continental shelf (the shallow offshore basin sites Msufi # 1, Mtiki # 1 and Mkongo # 3), one hundred Cretaceous cutting samples from one well from the deep offshore basin (Mvule # 1), and twenty-nine Cretaceous core samples from shallow boreholes from Tanzania Drilling Project (TDP) sites 21, 24, 36 & 37.Biostratigraphic results are limited, with the three shallow offshore basin wells proving largely barren of palynomorphs. The samples from the deep offshore basin (Mvule #1) produced the highest species richness, and although lacking many age-diagnostic taxa, palynological analysis has permitted the recognition of three dinocyst-based bioevents, using first downhole occurrences of taxa, as is appropriate for borehole studies. The four TDP boreholes yielded very restricted palynological assemblages, but a series of downhole dinocyst bioevents have been recognised in the core material, and although not defined using definitively age-diagnositic taxa, the events have been dated by correlation with existing calcareous microfossil biozonations. The sedimentary organic matter (palynofacies) analyses of the onshore and shallow offshore basin sites indicates the sediments studied were deposited in oxic open shelf conditions in close proximity to land, due to the high supply of terrestrial input diluting other palynomaceral components. Certain stratigraphic intervals were subject to periodic lowering of the oxygen conditions. The samples from the deep offshore basin well (Mvule #1) indicates a more marine-influenced setting. Overall, all samples are dominated by Type III kerogens, which are indicative of gas-prone source rocks. The organic richness (total organic carbon: TOC) results range from 0.1% to 3.4% TOC, demonstrating good source potential. In particular, the TOC values for the shallow offshore basin wells are as follows: for Msufi # 1, TOC ranges from 0.3-0.8%; for Mtiki #, 0.1-3.0%; for Mkongo # 3, 0.4-1.1%, and for the deep offshore well Mvule # 1, the TOC values range from 1.0-3.4%. Thermal maturity of the sediments was assessed using vitrinite reflectivity (Rv %), and values range from 0.3-3.4% Rv, indicating mature to post-mature maturity levels, and thus that the sediments studied have reached values appropriate for hydrocarbon generation. Computer modelling of the burial histories of the successions studied reveals that they have entered the window for early liquid hydrocarbon generation and reached the stages for wet-dry gas generation.

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SABBAG, MAURICIO G. "Estudo da migração de radionuclídeos em depósito para fontes seladas tipo poço tubular." reponame:Repositório Institucional do IPEN, 2013. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10503.

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Made available in DSpace on 2014-10-09T12:41:13Z (GMT). No. of bitstreams: 0
Made available in DSpace on 2014-10-09T14:08:33Z (GMT). No. of bitstreams: 0
Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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31

Perdigao, Cristhiana. "Assessment of horizontal bore drains performance in brown coal mines in the Latrobe Valley." Thesis, Federation University Australia, 2021. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/181877.

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Horizontal bores are essential infrastructures for maintaining the stability of open-pit mine batters. The infiltration of water from large surface catchments during rain events and induced deformation caused by mining activities can cause the build-up of pore water pressures in mine batters, potentially leading to catastrophic slope failures. A field investigation unit containing a camera has been developed to survey long (>300m) horizontal bores. Features observed using the camera along the profile of horizontal bores are discussed. Water flow was quantified by flow meters. X-Ray Diffraction (XRD) was undertaken to investigate the water precipitates within the selected bores. Water flow temperature was recorded to test the hypothesis of a possibility to indicate whether a borehole was draining from the saturated zone or from the surface water through its temperature. The investigations have been conducted to determine the cause of change in the efficiency of horizontal boreholes and find a reliable measure to assess longevity and performance of horizontal drains. Bore efficiency has been defined as the bore functioning as a preferential path for water within the batter to be drained out to reduce the saturated zone and associated pore water pressures within the batter. The results suggest blockages and fractures inside the bores can be considered the leading cause of the change in the efficiency of a bore. Blockages occur because of sediment accumulation and because of coal chunks from internal wall collapses. Internal fractures affect efficiency when they become the water preferred path; thus, retaining water flowing within the batter. The bore’s longevity is considered the period of the bore is considered effective. Water flow measurement is suggested as a reliable measure to assess bores’ longevity.
Masters by Research

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Maxime, Arsène Duguay. "Permafrost Changes Along the Alaska Highway Corridor, Southern Yukon, from Ground Temperature Measurements and DC Electrical Resistivity Tomography." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/24300.

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Permafrost temperatures were measured by the Geological Survey of Canada (GSC) in 1977-1981 at boreholes along a proposed pipeline route in the southern Yukon. Analysis of climate station records indicate that mean annual air temperatures in the region have since increased by 0.5-1.0˚C. Renewed interest in the pipeline and the need to develop adaptation strategies for existing highway infrastructure have meant that information on permafrost and geotechnical conditions must be updated. To accomplish this goal, a total of eight GSC boreholes ranging in depth from 5-9 m were located, unblocked of ice and instrumented with thermistor cables and data-loggers to permit renewed ground temperature monitoring. Manual temperature measurements were also taken at four other shallow boreholes. Electrical resistivity tomography (ERT) surveys were conducted at each site. MAGTs below 1 m at permafrost sites in the study area range from -0.2˚C to -1.5˚C with permafrost depths greater than 25 m. The permafrost at the study sites can be classified as sporadic discontinuous and extensive discontinuous. Ground temperatures indicate that permafrost can persist under warmer climatic conditions as long as it remains protected by its ecosystem properties. Thermal monitoring for 2011-2012 shows an average increase of 0.5-1.0˚C when compared to the original 1978-1981 ground temperatures. This slow rate of ground warming is mainly attributed to a combination of limited climate change, especially in the south of the study area, ground temperatures close to 0˚C, and the possible disturbance of sites from the removal of vegetation prior to the original measurements being made. ERT surveys conducted at most borehole sites show deeper thaw or taliks where the cleared cut-line used for geophysical work in the 1970s is crossed. These results indicate the impacts of climate change and environmental change in the study area over the past three decades. They appear to match the relatively slow rates of ground warming observed elsewhere in northern Canada where permafrost temperatures are close to 0˚C and where warming also requires changes in latent heat due to internal thaw. TTOP equilibrium modelling suggests that if climate change is responsible for the ground warming, most of the change can be attributed to the step-like MAAT increase that occurred between 1975-1976.

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33

Salge, Tobias. "The ejecta blanket of the Chicxulub impact crater, Yucatán, Mexico petrographic and chemical studies of the K-P section of El Guayal and UNAM boreholes /." [S.l.] : [s.n.], 2007. http://deposit.ddb.de/cgi-bin/dokserv?idn=983173230.

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Giunta, Fabio. "Techno-economic assessment of CO2 refrigeration systems with geothermal integration : a field measurements and modelling analysis." Thesis, KTH, Energisystem, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-289445.

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Several CO2 transcritical booster systems in supermarkets use the potential of integrating geothermal storage, enabling subcooling during warm climate conditions as well as being a heat source during cold climate conditions. First of all, field measurements of one of these systems located in Sweden were analysed with particular focus on the heat-recovery performance. The best theoretical operational strategy was compared to the one really implemented and the differences in the annual energy usage were assessed through modelling. The results show that an alternative to the best theoretical operational strategy exists; heat can be extracted from the ground while low-temperature heat is rejected by the gas cooler. Such an alternative strategy has important technical advantages with a negligible increment of the energy usage. In the second part of this work, the benefits of geothermal subcooling were evaluated. Applying the BIN hours method, it was demonstrated that this system is expected to save on average roughly 5% of the total power consumption, in Stockholm’s climate. The models utilized for the winter and summer season were combined to find the relationship between geothermal storage size and annual energy savings. In this way, it was possible to calculate the present value of the operational savings for the study case. Furthermore, a general methodology for assessing the economic feasibility of this system solution is presented. Finally, several scenarios were investigated to produce parametric curves and to perform a sensitivity analysis. Comparing the results with the typical Swedish prices for boreholes, the cases where this system solution is economically justified were identified. These are supermarkets with a Heat Recovery Ratio (HRR) higher than the average. For examples, supermarkets supplying heat to the neighbouring buildings (considering the Stockholm’s climate, systems with an annual average HRR of at least 70%). Relying only on savings from subcooling was found to be not enough to justify a geothermal storage, a not-negligible amount of heat must be extracted in winter. Finally, some interesting concepts and alternatives to a geothermal integration are presented to point out relevant future work.

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Mosavel, Haajierah. "Petrophysical characterization of sandstone reservoirs through boreholes E-S3, E-S5 and F-AH4 using multivariate statistical techniques and seismic facies in the Central Bredasdorp Basin." Thesis, University of the Western Cape, 2014. http://hdl.handle.net/11394/3984.

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>Magister Scientiae - MSc
The thesis aims to determine the depositional environments, rock types and petrophysical characteristics of the reservoirs in Wells E-S3, E-S5 and F-AH4 of Area X in the Bredasdorp Basin, offshore South Africa. The three wells were studied using methods including core description, petrophysical analysis, seismic facies and multivariate statistics in order to evaluate their reservoir potential. The thesis includes digital wireline log signatures, 2D seismic data, well data and core analysis from selected depths. Based on core description, five lithofacies were identified as claystone (HM1), fine to coarse grained sandstone (HM2), very fine to medium grained sandstone (HM3), fine to medium grained sandstone (HM4) and conglomerate (HM5). Deltaic and shallow marine depositional environments were also interpreted from the core description based on the sedimentary structures and ichnofossils. The results obtained from the petrophysical analysis indicate that the sandstone reservoirs show a relatively fair to good porosity (range 13-20 %), water saturation (range 17-45 %) and a predicted permeability (range 4- 108 mD) for Wells E-S3, E-S5 andF-AH4. The seismic facies model of the study area shows five seismic facies described as parallel, variable amplitude variable continuity, semi-continuous high amplitude, divergent variable amplitude and chaotic seismic facies as well as a probable shallow marine, deltaic and submarine fan depositional system. Linking lithofacies to seismic facies maps helped to understand and predict the distribution and quality of reservoir packages in the studied wells

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Geel, Claire. "Diagenetic, thermal and provenance histories of the Permian lower Ecca Group based on two newly drilled boreholes in the western and eastern main Karoo Basin, South Africa." Doctoral thesis, Faculty of Science, 2020. http://hdl.handle.net/11427/32639.

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Fine-grained sedimentary rocks of the Lower Permian lower Ecca Group in the Main Karoo Basin (MKB) in southern Africa have been identified to form a possible unconventional hydrocarbon reservoir, the gas potential of which is still relatively unknown. The lower Ecca Group is comprised of flysch-like successions of the Prince Albert, Whitehill and Collingham formations, which were impacted by diagenesis as well as contact and regional and metamorphism. Studies of fine-grained sedimentary rocks are notoriously complex as mechanical breakdown and diagenesis result in mineralogical changes and loss of source rock information. Therefore, a variety of analytical techniques are required for their thorough investigation. In this study, we analyse Permian rocks from two boreholes (KZF-1 and KWV-1) that were drilled ~ 830 km apart in the western and eastern MKB, respectively, and compare their composition, thermal maturity and petrophysical characteristics to better assess the hydrocarbon potential of the lower Ecca Group. In addition, whole rock geochemistry is used to reconstruct the palaeo-environment and provenance settings. Lastly, we investigate the influence of shale composition, porosity, well pressure and temperatures on their geomechanical properties such as compressive strength and elastic moduli. Sedimentary rocks in both boreholes were affected by burial and regional metamorphism (linked to orogenic events), but the sedimentary rocks in BH KWV-1 were also altered by contact metamorphism due to dolerite intrusions in the Early Jurassic. Major mineralogical differences between the boreholes include: 1) Fesilicate (greenalite); carbonates (rhodochrosite and dolomite) and Mn nodules (birnessite) being found only in BH KZF-1; and 2) metamorphic minerals such as garnet, cordierite, staurolite being found only in BH KWV-1. The results show that these rocks are over mature as evidenced by the low quantity of free hydrocarbons (S1 peak; 0.02–0.06 mg/g) and potential to release hydrocarbons (S2 peak; 0.06– 0.14 mg/g) and low hydrogen index (HI) values (2.40–167 mg HC/g TOC) from Rock Eval pyrolysis accompanied with high vitrinite/bitumen reflectance (BH KZF-1 is VRo= 4 and BH KWV-1 is BRo= 5). The total organic carbon (TOC) content is the highest in the Whitehill Formation in both boreholes (BH KZF-1: 5.17 wt%; BH KWV-1: 4.87 wt%). Burial diagenesis significantly reduced interparticle porosity and most of the measurable porosity comes from intraparticle nano-pores confined to organic matter v and dolomite. Meso- and macro-porosity are limited to phyllosilicates, pyrite framboids and microfractures. The Chemical Index of Alteration (CIA) is highest for the Prince Albert Formation (72– 78) as the palaeo-environment changed from an ice-house to a green-house, postglacial period in southern Gondwana. Enrichment of trace elements in BH KZF-1 and BH KWV-1 are in order: Mn > Ba > Zn > Co > Cu > V > Rb > Cr > Ni; and for BH KWV-1: Mo > Ba > Cu > Zn > Mn > V > Co > Cr > Rb > Ni. Geochemical proxies used in determining levels of anoxia were: V/Cr, V(V+Ni), Ni/Co and Fe-S-TOC plots. Salinity was deduced using Rb/K ratios and with identification of potential benthic foraminifera and minerals such as apatite, birnessite and phosphate nodules, which are assumed to be syn-sedimentary in origin. Overall, the geochemical results indicate that the depositional conditions fluctuated with respect to anoxia, salinity levels, and that while the sedimentation rates were low and the bio-productivity level was high, at least episodically. Provenance was investigated using Discriminant Function Diagrams, Principle Component Analysis Results (PCA), Zr/Ti ratios and the Index of Compositional Variability (ICV). Results indicate that the Prince Albert and Whitehill formations in the western MKB comprises sediment that was mostly sourced from the Cambrian to Late Carboniferous Cape Granite Suite, Cape Supergroup, the Dwyka Group and possibly the Precambrian Kango Group (Saldania Belt) and/or the Namaqua-Natal Belt. The Prince Albert and Whitehill formations in the eastern MKB have a mafic signature, indicating that these sediments may have been derived from the PermoCarboniferous Dwyka Group, Precambrian Kaapvaal Craton, Natal Belt (Tugela Terrane), Natal Group and the Pan-African Mozambique and Maud Belts. The mudstone and wackes in the Collingham Formation were mostly sourced from the quartz-arenites and granites that were most likely associated with the Cape Fold Belt, the orogen immediately adjacent to and largely coeval with the MKB. Geomechanical results from BH KZF-1 show that the lower Ecca Group has a high proportion (~ 50–70 vol%) of mechanically strong minerals (e.g., quartz, feldspar, pyrite), ~ 30–50 vol% weak minerals (e.g., clay, organic matter) and up to ~ 0–50 vol%, highly variable, intermediate components (e.g., carbonates). Constant strain rate deformation experiments (T ≤ 100 °C; p ≤ 50 MPa) and compressional tests performed perpendicular and parallel to bedding show that the Prince Albert Formation is the strongest and most brittle followed by the Collingham Formation and then the Whitehill Formation. Triaxial compressive strength as well as static Young's vi moduli increased with increasing hard minerals and decreased with increasing mechanically weak minerals and porosity. On comparison with European and American shales, the shales in the lower Ecca Group are geomechanically stronger and more brittle, and thus may allow for fracture propagation without rock breakdown under pressure. The lower Ecca Group varies from the western to the eastern MKB in mineralogy, thermal maturity, palaeo-depositional environment and provenance. These observations directly challenge the previous assumptions that these black shales were deposited under predominantly anoxic conditions. Indeed, during deposition, the levels of anoxia appear to have been inconsistent across the MKB and were likely dependent on the changing primary bio-productivity levels, sedimentation rates and basin morphology. Neither borehole contained significant gas, likely due to degasification by dolerite intrusions in the Early Jurassic and structural deformation during syn- and post-Karoo times. In summary, this study quantitatively confirms that the lower Ecca Group has the potential to be an easily frackable, unconventional shale gas reservoir. However, this study also attests to the compositional and geomechanical complexity of these Karoo rocks, and this inevitably translates to a gas potential that is expected to vary significantly across the basin.

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Pimenta, de Castro Fonseca Catarina. "The death of the communal handpump? : rural water and sanitation household costs in lower-income countries." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/8512.

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Rural water supply and sanitation in low and middle income countries face the same challenges now as in the 1970s. Despite massive efforts in providing communal “borehole with handpump” and “improved latrines” to improve the lives of millions of people, this traditional approach to development is failing to deliver long lasting improved services - even if for the last 40 years many attempts have been made to solve problems in the approach. The main research question is “Can low-income rural families pay for rural water supply and sanitation?” This thesis has analysed household poverty and costs on water and sanitation services in Mozambique and Ghana based on 3,049 surveys collected between 2009-2010 by the IRC International Water and Sanitation Centre WASHCost project. Evidence shows that even extreme poor households can and do pay for improved water and sanitation services. However, households prefer to pay for more expensive services to reduce the distance required to collect water instead of paying for the cheaper maintenance of communal (further away) sources. For sanitation, without targeted support towards the poorest, improved latrines might be unaffordable. Also, without follow up support, behaviour change and health impact will not be sustained. Small increases in the wealth of the poorest have a large impact on the services demanded in terms of quantity, distance and time spend as well as an increase in the level of capital and maintenance expenditure. Ultimately, the world now is not the same as in the 1970s and for achieving universal sustainable coverage for water and sanitation we need to rethink the failed traditional approach to development in low income countries with a deeper understanding of the market segmentation in the lowest quintile of the population and their real aspirations and demand.

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Жулев, А. А. "Исследование напряженно-деформированного состояния цементного кольца буровых скважин в зависимости от конфигурации." Thesis, Сумский государственный университет, 2013. http://essuir.sumdu.edu.ua/handle/123456789/31819.

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Эффективность работы буровых скважин в значительной степени зависит от методов их крепления и цементирования. Качественное цементирование должно надежно разобщить продуктивные пласты от водоносных, укрепить склонные к обвалам породы, предохранить от коррозии обсадную колонну и повысить её несущую способность и долговечность. Стоимость глубоких скважин (до 12000 метров) весьма высока, а ущерб от некачественного их крепления может быть ещё большим, вплоть до их полной потери. Поэтому проблема обеспечения качественного разобщения пластов является в настоящее время наиболее важной проблемой в достижении долговечности и продуктивности скважин. При цитировании документа, используйте ссылку http://essuir.sumdu.edu.ua/handle/123456789/31819

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Kukat, James Pkemoi. "Development and Validation of a Remote Sensing Model to Identify Anthropogenic Boreholes that Provide Dry Season, Refuge Habitat for Anopheles Vector Mosquitoes in Sub-Saharan Africa." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6287.

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A lack of surveillance systems is an impediment to public health intervention for perennial vector-borne disease transmission in northern tropical savanna region of Kenya. The population in this area are mostly poor nomadic pastoralists with little acquired functional immunity to Plasmodium falciparum, due to infrequent challenges with the parasite. A common characteristic in tropical savanna climatic zone is the availability of riverbeds that have anthropogenic boreholes that provide malaria vector mosquitoes, such as Anopheles gambiae s.l and Anopheles funestus, with aquatic refuge habitats for proliferation and endemic transmission to proximity human households during the dry-season. Unfortunately, currently there have been no entomological investigations employing field or remotely sensed data that can characterize and model anthropogenic borehole habitats focusing on the dry-land ecology of immature Anopheles mosquitoes in sub-Sahara Africa. The goal of this investigation was three-fold: (I) to employ WorldView-3 (0.31 meter spatial resolution) visible and near infra-red waveband sensor data to image sub-Saharan land cover associated with vector-borne disease transmission; (II) to remotely identify anthropogenic boreholes in three riverbeds that were surveyed to determine whether they provide malaria vectors with refuge habitat and maintain their population during the dry season in Chemolingot, Kenya, and (III) to obtain a radiometric/spectral signature model representing boreholes from the remotely-sensed data. The signature model was then interpolated to predict unknown locations of boreholes with the same spectral signature in Nginyang Riverbed, Kenya. Ground validation studies were subsequently conducted to assess model’s precision based on sensitivity and specificity tests.

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Berro, Mouhammed Jandal [Verfasser], Matthias [Akademischer Betreuer] Reich, Matthias [Gutachter] Reich, Catalin [Gutachter] Teodoriu, and Gerhard [Gutachter] Thonhauser. "Development and testing of alternative methods for speeding up the hydraulic data transmission in deep boreholes / Mouhammed Jandal Berro ; Gutachter: Matthias Reich, Catalin Teodoriu, Gerhard Thonhauser ; Betreuer: Matthias Reich." Freiberg : Technische Universität Bergakademie Freiberg, 2019. http://d-nb.info/1221139347/34.

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Karpfinger, Florian. "Modelling borehole wave signatures in elastic and poroelastic media with spectral method." Thesis, Curtin University, 2009. http://hdl.handle.net/20.500.11937/2447.

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Borehole sonic measurements are an important tool to characterize formation and completion properties of hydrocarbon or water reservoirs. Such measurements can provide direct information about rock physical parameters such as permeability or elastic moduli. These properties are obtained from guided waves propagating along boreholes. The so called tube wave or Stoneley wave is a symmetric mode which compresses the fluid column leading to a piston like motion. If the medium around the borehole wall is permeable, the radial expansion of the fluid column will result in fluid flow across the borehole wall. This results in a sensitivity of the tube wave signature to the permeability of the surrounding formation which manifests itself in a characteristic dispersion and attenuation of the tube wave. Information about the permeability of the surrounding formation provides essential knowledge for reservoir characterization.In addition to the traditional method of using tube wave signatures for formation permeability estimations, the same approach may be used for production monitoring. In sand reservoirs a complicated borehole completion is installed during the production phase for the purpose of controlling sand production. In such a setup highly permeable layers such as a sand screen or a gravel pack are used to prevent sand production.The problem with such completions is that they are very expensive to install and susceptible to plugging or corrosion. No permanent surveillance tool exists to date which allows diagnosis of problems in sand-screened deepwater completions. However, the recently proposed Real-Time Completion Monitoring (RTCM) uses the signature of tube waves to identify permeability changes: the increase of the tube wave velocity can indicate a decrease of permeability and vice versa. Therefore, RTCM has potential to identify problems in sand-screened deepwater completions.In order to understand the acoustic response of such deepwater completions, the dispersion and attenuation of tube waves in this complicated setup needs to be studied. To this end I have developed a modelling algorithm based on a spectral method. The developed algorithm computes the dispersion and attenuation of borehole modes propagating in a cylindrically layered structure with an arbitrary number of fluid, elastic and poroelastic layers. The numerical algorithm discretizes the medium along the radial axis using Chebyshev interpolation points derived from Chebyshev polynomials. The differential operators are discretized using spectral differentiation matrices. Thus, for any number of layers, the corresponding equations can be expressed as a generalized algebraic eigenvalue problem. For a given frequency, the eigenvalues correspond to the wavenumbers of different modes. The eigenvectors, computed along with the eigenvalues, correspond to the displacement potentials. They can be used to obtain the variation of displacement and stress components along the radius of the structure.In this thesis the spectral method was first developed for structures with an arbitrary number of fluid and elastic layers. Subsequently, the algorithm was extended for poroelasticity. The results produced by the modelling program are benchmarked against analytical solutions. Such analytical solutions are known for elastic and poroelastic cylinders as well as fluid filled tubes. The tube wave dispersion in a fluid-filled borehole surrounded by an elastic or poroelastic formation obtained with the spectral method was compared to the analytical low-frequency solution.I obtained the dispersion of the two tube waves propagating in a four layer completion model: fluid – permeable sand-screen – fluid – elastic casing. Varying the permeability of the sand-screen layer allowed me to account for the effect of fluid flow across this layer. Being able to obtain the acoustic response can help to identify broken fluid communication which increases the tube wave velocity. A corroded sand-screen has an extremely attenuated tube wave signature.Furthermore, I have implemented the more complex model of a borehole surrounded by an altered zone in the algorithm. Due to drilling damage the altered zone is an area of reduced permeability. In order to account for the effect of the altered zone on the tube wave signature, up to ten layers were used with stepwise increase of permeability from the borehole towards the formation. Overall, the spectral method proved to be a valuable algorithm to model wave propagation in cylindrical structures.Using borehole modes to evaluate the physical properties of the formation or completions is an important application. However, in borehole seismic modelling, such as crosshole or VSP, it is also important to account for the effect of boreholes and the associated modes. Since the borehole radius is a thousand times smaller then the investigated volume it would require a prohibitively small grid size to explicitly model the borehole. However, it is possible to effectively represent a borehole as a superposition of point sources. This mimics the presence of borehole modes. In order to implement this technique for poroelasticity, it is necessary to model source signatures in poroelastic media. To this end I have analyzed the radiation characteristics and moment tensor solutions for various source types. Together with the spectral method these point source representations can be used to model the effect of boreholes. This will pave the way for more efficient poroelastic seismic modelling in various fluid-filled boreholes and completions.

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Raschke, Marcus, and Victor Peterson. "Termisk energilagring i borrhål : En studie av borrhålets temperaturinverkan på värmepumpens värmefaktor." Thesis, KTH, Byggteknik och design, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-147305.

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Sverige har en hög andel installerade bergvärmepumpar, som är en typ av vätska-vatten värmepump. Ett problem som finns för befintliga bergvärmesystem är att berget med tiden kyls ned då returslangen till borrhålet konstant levererar kyla till berget. Till följd av detta mister systemet en betydande del av sin verkningsgrad samtidigt som det i extrema fall kan leda till permanent isbildning i borrhålet. Ett sätt att motverka detta problem är att tillämpa termisk energilagring i bergvärmesystemets borrhål. Den internationella benämningen för denna teknik är ”Borehole Thermal Energy Storage, BTES”. Rapporten har behandlat en friliggande enplansvilla med ett befintligt bergvärmesystem som tillämpar termisk energilagring i bergvärmesystemets borrhål med solvärme. Två beräkningsfall har gjorts och resultatet från simuleringarna i en upprättad beräkningsmodell visar att en temperaturhöjning i borrhålet inte alltid innebär en årlig energibesparing. Vid varje grads temperaturhöjning sker en ökning av värmepumpens COP med ca 1,85 % enligt ett linjärt samband för höga temperaturdifferenser över värmepumpen. Detta motsvarar en kostnadsbesparing på 1,02 %/°C. Detta gäller för normala förhållanden med en framledningstemperatur för tappvarmvatten och rumsvärmare på 55 ⁰C. Med en högre energiförbrukning finns alltså större besparingar att göra. Vid mycket låga temperaturdifferenser mellan förångare och kondensor sker dock större procentuella förändringar, vilket medför att lågtemperatursystem kan bidra till en större energibesparing. I normalfallet är dessa system svåra att räkna hem för småhus. För en god lönsamhet krävs en optimerad systemlösning och effektiv styrning av cirkulationspumpar och andra samspelande komponenter med en PLC. I framtiden kommer dock sannolikt värmepumparnas mekaniska verkningsgrad att öka med bättre teknik och även energipriset som följd av politiska beslut, tillgång etc. Detta innebär att varje besparad kilowattimme kommer att bli mer värd.
Sweden has a high proportion of installed geothermal heat pumps, which are a type of liquid -water heat pump. One problem that exists for existing geothermal heating systems is that the rock in time cool down when the return hose to the borehole constantly supply cooling to the rock. As a result of this the system loses a significant portion of their efficiency while in extreme cases has led to the permanent ice in the borehole. One way to counter this problem is to apply thermal energy storage in the geothermal heating systems borehole. The international term for this technique is "Borehole Thermal Energy Storage, BTES". This report has analyzed a detached single storey house with an existing geothermal heating system utilizing thermal energy storage in the geothermal heating systems borehole with solar heating. Two calculation cases has been made and the results of the simulations in an established computational model shows that an increase in temperature in the borehole does not always result in an annual energy savings. Each degree of increased temperature is an increase in the heat pumps COP of 1.85 %, according to a linear relationship for high temperature differences across the heat pump. This results in a cost saving of 1.02 %/°C. This applies to normal conditions with a radiator temperature at 55 ⁰ C. With higher energy consumption can greater savings be made. At very low temperature differences between the evaporator and condenser is however larger percentage changes made, which means that low temperature systems can lead to greater energy savings. Typically, these systems are difficult to recoup for small detached houses. For a good profitability requires an optimized system solution and efficient control of circulation pumps and other interacting components with a PLC. In the future the heat pump mechanical efficiency will probably increase with better technology and even energy prices as a result of political decisions, access, etc. This means that each spared kilowatt hour will be worth more.

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Shtuka, Arben. "Simulation, traitement et visualisation des images numériques : apport du codage par indicatrice en géostatistique." Vandoeuvre-les-Nancy, INPL, 1994. http://www.theses.fr/1994INPL139N.

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La thèse se compose de trois parties. La première partie est consacrée à une nouvelle méthode d'interpolation des champs vectoriels utilisant les moindres carrés a l'aide des polynômes orthogonaux. Cette méthode a été appliquée à la modélisation des trajectoires de forage de deux gisements en Albanie. La seconde partie concerne les méthodes géostatistiques d'estimation à l'aide des indicatrices. Les méthodes conventionnelles d'interpolation (krigeage des indicatrices) sont difficilement utilisables et nécessitent une connaissance préalable des fonctions de covariances pour chaque valeur de coupure. Étant donné ces difficultés, deux stratégies ont été suivies. La première consiste à construire un modèle général des fonctions de covariances des indicatrices en s'appuyant sur les propriétés spectrales. La seconde stratégie consiste a utiliser une autre méthode d'interpolation des indicatrices à l'aide de DSI(discrete smooth interpolation). Cette méthode a beaucoup d'avantages par rapport aux méthodes classiques: rapidité, simplicité et surtout respect des contraintes nécessaires pour que les indicatrices interpolées soient une estimation de la répartition locale. La dernière partie est consacrée aux traitements et a l'analyse d'images numériques. L'utilisation de plus en plus fréquente d'images numériques en géosciences a conduit au développement d'un logiciel spécifique IMEGEO (images géologiques). Le logiciel a été conçu selon les principes suivants: portabilité, interactivité, modularité et configuration systeme minimal. Dans sa version initiale, IMGEO était un outil de visualisation des images en deux dimensions, actuellement il représente un logiciel plus complet contenant des modules d'analyse

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Oberdorfer, Phillip [Verfasser], Martin [Akademischer Betreuer] Sauter, and Ekkehard [Akademischer Betreuer] Holzbecher. "Heat Transport Phenomena in Shallow Geothermal Boreholes : Development of a Numerical Model and a Novel Extension for the Thermal Response Test Method by Applying Oscillating Excitations / Phillip Oberdorfer. Gutachter: Martin Sauter ; Ekkehard Holzbecher. Betreuer: Martin Sauter." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2014. http://d-nb.info/1047932245/34.

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Lo, Tien-when. "Seismic borehole tomography." Thesis, Massachusetts Institute of Technology, 1988. http://hdl.handle.net/1721.1/54325.

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Du, Preez M., and P. Hertzog. "Ultrasonic borehole flowmeter." Interim : Interdisciplinary Journal, Vol 7, Issue 1: Central University of Technology Free State Bloemfontein, 2008. http://hdl.handle.net/11462/378.

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Published Article
Although research has been conducted in the field of Acoustic Doppler Borehole Flowmeters (ADBF), it has been focused on point source of flow and three dimensional borehole flow techniques. However as of yet, no studies have been conducted on the possible use of Acoustic Doppler Borehole Profiling (ADBP). This technique of borehole flow measurement is possibly a revolutionary concept in how vertical flow in a borehole is measured. It makes use of a single inexpensive transducer that can float on the surface of the water in a borehole and use Acoustic Doppler techniques to profile the flow in a borehole. No complicated and expensive flow probe winching systems will be required. Another added benefit of the ADBP will be the non-evasive technologies that comprise its design. Current borehole flow probes are required to be present at the point of flow measurement in the borehole. The presence of the probe inadvertently alters the flow in the borehole by adding resistance to the flow in the borehole. Under stressed or pumped flow tests these flow resistance effects cause sufficient pressure gradients at the flow sensors to divert part of the flow away from the sensor. This causes erroneous readings of flow as a part of the flow in the borehole is not accounted for. In ADBP the sensor is not physically present at the point of flow being read. This makes the ADBP technique of borehole flow measurement far more representative of the natural flow conditions in the borehole under ambient and stressed conditions.

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Башлак, Ірина Анатоліївна, Ирина Анатольевна Башлак, Iryna Anatoliivna Bashlak, V. S. Kovalenko, and B. A. Fostenko. "Kola superdeep borehole." Thesis, Видавництво СумДУ, 2010. http://essuir.sumdu.edu.ua/handle/123456789/17574.

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FERREIRA, EDUARDO G. A. "Avaliação da alteração nas propriedades da pasta de cimento em ambiente de repositório." reponame:Repositório Institucional do IPEN, 2013. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10208.

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Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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Namuq, Mohammed Ali. "Simulation and modeling of pressure pulse propagation in fluids inside drill strings." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2013. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-107969.

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Modern bottom-hole assemblies are equipped with various sensors which measure the geological and directional information of the borehole while drilling. It is very crucial to get the measured downhole information to the surface in real time in order to be able to monitor, steer and optimize the drilling process while drilling. The transmission of the information to the surface is most commonly carried out by coded pressure pulses (the technology called mud pulse telemetry) which propagate through the drilling mud inside the drill string towards the surface. However, hardly any specific experimental research on the hydraulic data transmission can be found in the literature. Moreover, it is essential to use a reliable model/simulation tool which can more accurately simulate the pressure pulse propagation in fluids inside drill strings under various drilling operation conditions in order to improve the performance of the data transmission process. The aims of this study are to develop and test a laboratory experimental setup, a simulation model and a novel method for detecting and decoding of measurement while drilling pressure pulse propagation in fluids inside drill strings. This thesis presents a laboratory experimental setup for investigating the process of data transmission in boreholes by mud pulse telemetry. The test facility includes a flow loop, a centrifugal pump, a positive mud pulser or alternatively a mud siren, pressure transducers at four different locations along the flow loop and a data collection system. Moreover, it includes an “actuator system” for the simulation of typical noise patterns created by the common duplex or triplex mud pumps. This laboratory setup with great capabilities opens the way for testing and developing new concepts for data transmission. A theoretical model using ANSYS CFX11 (Computational Fluid Dynamics (CFD) commercial code) was successfully developed to simulate dynamic pressure pulse transmission behavior in the fluid inside the flow loop. The collected laboratory data which simulate various data transmission processes in boreholes were used to verify and calibrate the theoretical method. A pretty good agreement is achieved between the predicted and measured pressure pulses at different locations along the flow loop for positive pulses with various durations using different flow rates and for continuous pressure pulses using different carrier frequencies. A novel approach (continuous wavelet transformation) for detecting and decoding the received continuous pressure pulses in a noisy environment was applied to various simulated drilling operation conditions for data transmission in boreholes in the laboratory. The concept was registered at the German Patent and Trade Mark Office (DPMA) for a patent in 2011. The results indicate that the continuous wavelet transformation can be used to clearly identify and better detect the continuous pressure pulse periods, frequencies and discontinuity positions in the time domain compared to the conventional method (Fourier transformation). This method will contribute to the possibility of transmitting the data at higher rates and over longer distances. A concept for developing an innovative pulser using electrical discharge or acoustic sources for inducing pulses keeping the drill strings fully open (eliminating the problem of plugging the pulser by pumped lost circulation materials) and without any mechanical moving parts (eliminating the failure related to the pulser moving parts) was also registered at the German Patent and Trade Mark Office (DPMA) for a patent in 2012. With this pulser, it is expected that it would be possible to transmit the data over longer distances and at higher rates. Realizing the concept of the new pulser and using continuous wavelet transformation for detecting and decoding the pulser signal are recommended for future work.

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Fuenkajorn, Kittitep. "Borehole closure in salt." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184451.

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Constitutive laws are developed to predict creep (time-dependent) closure of boreholes in salt specimens subjected to various loading configurations. Rheological models (linear and nonlinear viscoelastic and viscoplastic models), empirical models, and physical theory models have been formulated from the results of uniaxial creep tests, strain and stress rate controlled uniaxial tests, constant strain rate triaxial tests, cyclic loading tests, and seismic velocity tests. Analytical solutions for a thick-walled cylinder subjected to internal and external pressures and for a circular hole in an infinite plate subjected to a biaxial or uniaxial stressfield have been derived from each of the linear viscoelastic models and empirical laws. The experimental results indicate that the salt samples behave as an elastic-viscoplastic material. The elastic behavior tends to be linear and time-dependent while the plastic deformation is time-dependent. The stress increment to strain rate increment ratio gradually decreases as the stress level increases. The transient potential creep law (ε(c) = κσᵝtᵞ) seems to give the simplest governing equation describing the viscoplastic behavior of salt during the transient phase. Variation of intrinsic properties which is mainly contributed by nonuniform distribution of intercrystalline gaps and air voids plays a more significant role upon instantaneous deformation than upon transient deformation. The mechanisms governing the time-dependent deformation are fracture propagation, plastic flow and dislocation of the salt crystals, and healing of the intercrystalline gaps and induced fractures. Different sets of test parameters (strain and stress rates, differential and confining stresses, and testing times) induce different degrees and combinations of deformational mechanisms, which lead to a variation of the fitting parameters of the potential law. The transient potential creep model does not accurately predict the results of triaxial and polyaxial borehole closure experiments, probably due to the predictive capability of the model or the methods used in multiaxial formulation, or both. Since the model parameters apparently depend upon the main mechanisms governing creep rate, prediction of the salt deformation around a borehole subjected to a high stress gradient by using only a set of model parameters may not be accurate.

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Dissertations / Theses on the topic 'Boreholes'

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