Dissertations / Theses: 'Petrophysics and rock mechanics'

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SANTIAGO, Karina Felícia Fischer Lima. "Determinação das constantes elásticas estáticas e dinâmicas das rochas da formação sousa, Bacia do Rio do Peixe, PB." Universidade Federal de Campina Grande, 2015. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/410.

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Neste trabalho estudam-se as propriedades físicas e mecânicas das rochas da Bacia do Rio do Peixe (BRP), provenientes do furo estratigráfico 1-BSB01-PB. Esta bacia, localizada no extremo oeste do estado da Paraíba, tem se tornado alvo de estudos exploratórios, face à ocorrência de óleo próximo a superfície, à NW da cidade de Sousa. Em sua caracterização faciológica, identificam-se cinco fácies sedimentares: calcilutito vermelho, calcilutito cinza, arenito, folhelho negro e marga. Por meio de ensaios de propagação de ondas sísmicas, experimentos de petrofísica básica, e ensaios mecânicos de compressão uniaxial com o martelo de Schmidt, determinam-se para as amostras de rochas da BRP, a porosidade, as densidades total e de grão, as velocidades sísmicas, a resistência mecânica e as constantes elásticas estáticas e dinâmicas, destacando-se o módulo de Young. Os resultados obtidos mostram que as rochas em estudo apresentam valores de porosidade entre 0,5 e 20%, resistência à compressão uniaxial de 18 a 93 MPa, módulos de Young dinâmicos entre 9 a 58 GPa, desde 1,1 até 6 vezes maiores que os correspondentes módulos estáticos. As correlações observadas para as diferentes propriedades físicas e mecânicas mostram-se fortemente influenciadas por características como presença de material carbonático, matéria orgânica, óleo e estruturas sedimentares e tectônicas, evidenciando a complexidade das rochas analisadas.
In this paper, studies on physical and mechanical properties of rocks from the stratigraphic hole 1-BSB01-PB, in the Rio do Peixe Basin (BRP), are performed. This basin, located in the far west of the state of Paraíba, has become the subject of exploration studies due to the occurrence of oil near the surface, in the NW of Sousa city. In his facies characterization is possible to identify five sedimentary facies: red calcilutite, gray calcilutite, sandstone, black shale and marl. From seismic wave propagation tests, experiments of basic petrophysics, mechanical tests on uniaxial compressive with Schmidt’s hammer, are determined for samples of BRP rocks the porosity, the bulk and grain densities, the seismic velocities, the mechanical strength and the static and dynamic elastic constants, highlighting the Young's modulus. The results obtained show that the studied rocks have porosity values between 0.5 and 20%, uniaxial compressive strength from 18 to 93 MPa, dynamic Young's modulus between 9 and 58 GPa, from 1,1 to 6 times greater than the corresponding static modules Correlations observed for the different physical and mechanical properties shows strongly influences by characteristics such as the presence of carbonate material, organic material, oil and sedimentary and tectonic structure, showing the complexity of the analyzed rocks.

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Slayman, Hadi. "Integration of rock typing with petrophysics in the Cooper Basin, Australia /." Title page, abstract and table of contents only, 2002. http://web4.library.adelaide.edu.au/theses/09SB/09sbs6319.pdf.

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Al-Harthy, Said Salim. "Laboratory investigation of petrophysical properties of sandstone rocks under true triaxial stress." Thesis, Imperial College London, 1999. http://hdl.handle.net/10044/1/8549.

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Binyatov, Elnur. "Sedimentological, Cyclostratigraphic Analysis And Reservoir Characterization Of Balakhany X Formation Within The Productive Series Azeri Field On C01 Well (offshore Azerbaijan)." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609628/index.pdf.

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The Azeri, Chirag, Gunashli (ACG) field is located offshore Azerbaijan. The reservoirs are multilayered sandstones forming traps within a major anticlinal structure. Proven crude oil reserves are estimated to contain 5.4 billion barrels of oil. In the past this area has been studied in regional detail but not at the reservoir scale with respect to the fluvio-deltaic sediments filling the northern shore of the ancient South Caspian Sea. The aim of this study is carried out the sedimentological, cyclostratigraphical analysis and reservoir characterization of Balakhany X Formation within the Productive Series which is considered to be one of the significant producing horizons. To be able to achieve this objective, a 30m thick section, which is mainly composed of siliciclastics, has been studied in detail on Balakhany X cores from C01 well Azeri field. In this study, detailed lithofacies analyses were performed and sandstone, mudstone, siltstone facies were recognized in the studied interval of the Balakhany X Formation. Litharenites and sublitharenites sandstones are the most abundant in the succession. Sedimentological analysis such as grain-size sphericity, provenance, XRD, SEM and grain surface texture were performed and their relationship with depositional environment were discussed. The grain size distribution of the samples along the succession shows distribution of fine to very fine sands. Sorting of sandstones ranges between moderately well to very well sorted. The provenance analysis of sandstones based on modal analysis of thin sections related to recycled orogen. According to interpretation of grain size parameters and grain surface textures analysis the main transporting agent of sands observed as wind, wave and river agents. High resolution cyclostratigraphy studies based on cm-m scaled cyclic occurrences of lithofacies along the measured section were performed. Milankovitch, sub-Milankovitch and millennial cycles were determined along the studied section. The petrophysical analysis revealed good to very good (18 to 24%) porosity and good permeability (10 to 538mD) in Balakhany X Formation. The porosity and permeability are affected by both textural and compositional controls. Grain size distribution along the reservoir section is fine to very fine sands. Influence of compaction was observed by the fractures and dissolutions on the sand grains. The calcite cement, grain-size variation, sorting and compaction are the main factors controlling porosity and permeability.

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Khather, Mohamed. "Experimental Evaluation of Variation in Petrophysical Properties during CO2 Injection in Carbonate Rocks: Effective Mechanisms." Thesis, Curtin University, 2018. http://hdl.handle.net/20.500.11937/73568.

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Core flooding experiments were conducted in this research to evaluate changes in petrophysical properties of a number of carbonate samples (limestone, dolostone and chalk). The experiments involved carbonated brine flooding, CO2 enhanced oil recovery (CO2-EOR), and Water-Alternating Gas (WAG) processes performed under in-situ reservoir conditions.

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Douglas, Kurt John Civil &amp Environmental Engineering Faculty of Engineering UNSW. "The shear strength of rock masses." Awarded by:University of New South Wales. School of Civil and Environmental Engineering, 2002. http://handle.unsw.edu.au/1959.4/19138.

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The first section of this thesis (Chapter 2) describes the creation and analysis of a database on concrete and masonry dam incidents known as CONGDATA. The aim was to carry out as complete a study of concrete and masonry dam incidents as was practicable, with a greater emphasis than in other studies on the geology, mode of failure, and the warning signs that were observed. This analysis was used to develop a method of very approximately assessing probabilities of failure. This can be used in initial risk assessments of large concrete and masonry dams along with analysis of stability for various annual exceedance probability floods. The second and main section of this thesis (Chapters 3-6) had its origins in the results of Chapter 2 and the general interests of the author. It was found that failure through the foundation was common in the list of dams analysed and that information on how to assess the strength of the foundations of dams on rock masses was limited. This section applies to all applications of rock mass strength such as the stability of rock slopes. Methods used for assessing the shear strength of jointed rock masses are based on empirical criteria. As a general rule such criteria are based on laboratory scale specimens with very little, and often no, field validation. The Hoek-Brown empirical rock mass failure criterion was developed in 1980 for hard rock masses. Since its development it has become virtually universally accepted and is now used for all types of rock masses and in all stress regimes. This thesis uses case studies and databases of intact rock and rockfill triaxial tests collated by the author to review the current Hoek-Brown criterion. The results highlight the inability of the criterion to fit all types of intact rock and poor quality rock masses. This arose predominately due to the exponent a being restrained to approximately 0.5 to 0.62 and using rock type as a predictor of mi. Modifications to the equations for determining the Hoek-Brown parameters are provided that overcome these problems. In the course of reviewing the Hoek-Brown criterion new equations were derived for estimating the shear strength of intact rock and rockfill. Empirical slope design curves have also been developed for use as a preliminary tool for slope design.

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SAVELY, JAMES PALMER. "PROBABILISTIC ANALYSIS OF FRACTURED ROCK MASSES." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184249.

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Stability analysis of rock masses composed of small, discrete rock blocks that are in-place and interlocked should consider four components of failure: (1) Sliding between blocks. (2) Shearing through rock blocks. (3) Rolling blocks in a shear zone. (4) Crushing of rock blocks. Statistical rock mass description is used to define the characteristics of the rock blocks and the block assemblage. Clastic mechanics is one method of predicting stresses produced by the arrangement of rock blocks and the loading conditions. Failure begins at a point of maximum stress behind the slope. Progression of the failure is assumed if the first block fails because adjacent blocks will become overstressed. The location of the point of maximum stress is determined from the shape and arrangement of the constituent rock blocks. Because strength is mobilized block-by-block rather than instantaneously along a continuous shear surface, sliding between blocks shows less stability than a soil rotational shear analysis or a rigid block sliding analysis. Shearing through rock blocks occurs when maximum shear stress exceeds rock shear strength. Crushing of rock blocks is predicted if the normal stress exceeds the compressive strength of the rock block. A size-strength relationship is combined with the rock block size distribution curve to estimate crushing strength. Rotating blocks in a shear zone have been observed in model studies and as a mechanism in landslides. Stability analysis assumes that the rock mass is sufficiently loosened by blasting and excavation to allow blocks to rotate. The shear strength of rolling blocks is dynamic shear strength that is less than static sliding shear strength. This rolling mechanism can explain release of slope failures where there are no other obvious structural controls. Stability of each component of rock mass failure is calculated separately using capacity-demand reliability. These results are combined as a series-connected system to give the overall stability of the rock mass. This probability of failure for the rock mass system explicitly accounts for the four components of rock mass failure. Criteria for recognizing rock mass failure potential and examples applying the proposed method are presented.

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Lock, Yick-bun. "An examination of failure criteria for some common rocks in Hong Kong /." Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B17665164.

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Akbarnejad, Nesheli Babak. "Rock mechanics aspects of blowout self-containment." [College Station, Tex. : Texas A&M University, 2006. http://hdl.handle.net/1969.1/ETD-TAMU-1835.

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Lanaro, Flavio. "Geometry, Mechanics and Transmissivity of Rock Fractures." Doctoral thesis, Stockholm : Tekniska högsk, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3168.

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Sun, Ning. "Development and validation of a design method coupling block theory and three-dimensional discontinuous deformation analysis." Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B31789122.

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Sun, Ning, and 孫宁. "Development and validation of a design method coupling block theory and three-dimensional discontinuous deformation analysis." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B31789122.

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Lee, Cheng-Haw. "Flow in fractured rock." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/184962.

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In fractured rocks of low permeability, the hydraulic properties of the rock mass are strongly influenced by the connectivity and fracture geometry of the fracture system, the stiffness and deformational properties of fracture surfaces and the geostatic stresses. This dissertation demonstrates through theoretical analysis the sensitivity of fracture connectivity and flow rate to fracture radius, fracture density and measurement scale. Percolation factor and percolation frequency are suggested as indices of connectivity and flow rate. Models of hydromechanical coupling, normal closure and simple geometrical joint systems are proposed to study fracture porosity and fracture permeability and are compared with measured values from published papers. Fracture surface characteristics are expressed as indices of JRC and JCS. The relation between fracture aperture and geostatic stress is also examined. Based on the percolation process, a three dimensional discrete fracture model with statistical parameters of fracture geometry is developed to investigate the relations between the connectivity and flow rate and the percolation factor and percolation frequency. This model has the capability to generate a fracture network and to solve for steady state flow. The flow through each fracture is discretized by the boundary element method. By performing numerical simulation, the percolation threshold was found to be in the range of 0.9 to 2.4 for orthogonal joint sets. There is a rapid increase in flow rate with increasing fracture density or fracture length as the percolation factor reaches the percolation threshold. The percolation factor and percolation frequency are scale-dependent. A fracture network with large fractures and a high fracture density has a high percolation frequency and a high percolation factor. A network with high percolation frequency and percolation factor has a high flow rate. A constitutive model linking the initial conducting aperture, mechanical conducting aperture, JRC, JCS, geostatic stress and fracture geometries can be used to predict fracture porosity and fracture permeability in terms of depth. Preliminary comparison with field data shows that models comprising three orthogonal sets and disc-type fracture models can be used to simulate observed behavior. Fracture porosity and fracture permeability based on a model of three orthogonal sets can be used to predict flow through volcanic rocks. For sedimentary rocks a model incorporating a model of three orthogonal sets and one parallel set can be used with varying levels of confidence.

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Wong, Wing-yee. "Permeability studies in rock fractures." View the Table of Contents & Abstract, 2002. http://sunzi.lib.hku.hk/hkuto/record/B30109334.

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Lindfors, Ulf. "Experimental study of the mechanics of rock joints." Licentiate thesis, Luleå tekniska universitet, 1996. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-25833.

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Xu, Chaoshui. "Fracture mechanics and its application in rock excavation." Thesis, University of Leeds, 1993. http://etheses.whiterose.ac.uk/754/.

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The two chevron notched specimen geometries for rock Mode I fracture toughness measurement, CB and SR, recommended by the ISRM have several disadvantages, such as very low loads required to initiate failure, complicated loading fixtures, difficult to be developed for rock mixed mode fracture testing, relatively large amounts of intact rock core needed for the test and complex specimen preparation for the SR geometry. The cracked chevron notched Brazilian disc (CCNBD) and the cracked straight through Brazilian disc (CSTBD) specimen geometries overcome these problems and they are believed to be ideal geometries for rock fracture investigations. The general case for the cracked Brazilian disc fracture problem is when the specimen is loaded diametrically with the crack inclined at an angle to the loading direction. Different combinations of Mode I and Mode II fracture intensities can be obtained simply by changing this angle and the loading fixture still remains as simple as for a normal Brazilian test. A special superimposition technique is developed to theoretically solve the stress intensity factor (SW) values for the CSTBD fracture problem with the help of dislocation and complex stress function methods. This evaluation can generate accurate SIF results for the problem with any crack length a(a/R) = 0.05-0.95, while the mixed mode SIF solution for a>0.60 has not been reached by previous researchers. The relative theoretical SW solution for the corresponding CCNBD fracture problem (single or mixed fracture modes) is obtained by using Bluhm's slice model proposed for general crack problems. Numerical calibrations for Mode I fracture problems of the CSTBD and the CCNBD specimens have been conducted by using 194 different specimen geometries and the results prove the correctness of the theoretical evaluations. The valid CCNBD geometrical range for a valid rock Mode I fracture toughness test is numerically investigated and then experimentally validated based on 40 different CCNBD geometries by using 42 different rocks. Experimental studies on the minimum specimen size requirement for a valid CCNBD rock Mode I fracture toughness test are also carried out and the approximate critical criteria is given. The great advantages of using the CCNBD specimens for rock fracture toughness measurement have been investigated and the documentation for recommending the CCNBD specimen geometry to the ISRM as the third suggested method for rock Mode I fracture toughness test is presented. The rock Mode I fracture toughness values are then related to rock conventional properties for the purpose of prediction. Rock cutting mechanics is analyzed by probabilistic fracture mechanics and Weibull's distribution model is found to better express the characteristics of rock cutting performance parameters. Some initial predictions for these parameters based on this mode are then presented.

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Bedi, Anmol. "A proposed framework for characterising uncertainty and variability in rock mechanics and rock engineering." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/18998.

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This thesis develops a novel understanding of the fundamental issues in characterising and propagating unpredictability in rock engineering design. This unpredictability stems from the inherent complexity and heterogeneity of fractured rock masses as engineering media. It establishes the importance of: a) recognising that unpredictability results from epistemic uncertainty (i.e. resulting from a lack of knowledge) and aleatory variability (i.e. due to inherent randomness), and; b) the means by which uncertainty and variability associated with the parameters that characterise fractured rock masses are propagated through the modelling and design process. Through a critical review of the literature, this thesis shows that in geotechnical engineering – rock mechanics and rock engineering in particular – there is a lack of recognition in the existence of epistemic uncertainty and aleatory variability, and hence inappropriate design methods are often used. To overcome this, a novel taxonomy is developed and presented that facilitates characterisation of epistemic uncertainty and aleatory variability in the context of rock mechanics and rock engineering. Using this taxonomy, a new framework is developed that gives a protocol for correctly propagating uncertainty and variability through engineering calculations. The effectiveness of the taxonomy and the framework are demonstrated through their application to simple challenge problems commonly found in rock engineering. This new taxonomy and framework will provide engineers engaged in preparing rock engineering designs an objective means of characterising unpredictability in parameters commonly used to define properties of fractured rock masses. These new tools will also provide engineers with a means of clearly understanding the true nature of unpredictability inherent in rock mechanics and rock engineering, and thus direct selection of an appropriate unpredictability model to propagate unpredictability faithfully through engineering calculations. Thus, the taxonomy and framework developed in this thesis provide practical tools to improve the safety of rock engineering designs through an improved understanding of the unpredictability concepts.

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Price, Jeffrey Richard. "Coupled analysis of two-phase flow in rough rock fractures." Access electronically, 2005. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20050819.153247/index.html.

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Szymakowski, Jerry. "Direct shear testing of jointed soft rock masses." Monash University, Dept. of Civil Engineering, 2003. http://arrow.monash.edu.au/hdl/1959.1/9573.

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Liu, Chi-hong. "Base friction modelling of discontinuous rock masses." Click to view the E-thesis via HKUTO, 2002. http://sunzi.lib.hku.hk/hkuto/record/B42577123.

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MOURA, Carlos Henrickson Barbalho de. "Estimativa de permeabilidade de rocha carbonáticas a partir de parâmetros do espaço poroso." Universidade Federal de Campina Grande, 2018. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/1615.

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Capes
A petrofísica computacional é uma técnica que vem sendo utilizada cada vez mais na indústria do petróleo para caracterizar reservatórios e simular computacionalmente o seu comportamento físico. Através dessa técnica é possível caracterizar um elevado número de amostras, sob diferentes condições ambientais, em um tempo relativamente curto. Este trabalho propõe um modelo de estimativa de permeabilidade que utiliza parâmetros petrofísicos retirados de imagens de microtomografia de raios x (µCT) e os compara com parâmetros petrofísicos medidos em laboratório. Foi analisado um conjunto de 19 amostras com características deposicionais, diagenéticas e texturais diferentes entre si, pertencentes às bacias do Araripe, Potiguar e Sergipe-Alagoas. Delas, 14 são de calcário, 2 de tufa calcária, 2 de caliche e 1 de dolomito. Em laboratório foi utilizado um permoporosímetro a gás para medir os parâmetros porosidade e permeabilidade. As amostras de µCT foram adquiridas com resolução em torno de 2,0 µm. O conjunto de imagens criado foi tratado no software Avizo Fire e foram extraídos os parâmetros porosidade, permeabilidade, conectividade e diâmetro equivalente de poros. Um modelo estatístico foi estabelecido para predição da permeabilidade a partir dos parâmetros do espaço poroso extraídos das imagens de µCT. Os resultados indicam que a conectividade dos microporos, inferida a partir do cálculo do Número de Euler em imagens 3D, é o parâmetro que exerce maior influência na estimativa da permeabilidade, seguida pela porosidade dos macroporos e pela conectividade dos macroporos. O modelo preditivo proposto apresentou um coeficiente de determinação de 0,994, mostrando-se bastante confiável para o grupo de amostras investigado.
Computational petrophysics is a technique that has been increasingly used in the petroleum industry to characterize reservoirs and to simulate computationally its physical behavior. Through this technique it is possible to characterize a big number of samples, under different environmental conditions, in a relatively short time. This work proposes a model of permeability estimation that uses petrophysical parameters taken from x - ray microtomography images (µCT) and compare them with petrophysical parameters measured in the laboratory. It was analyzed a set of 19 samples with different depositional, diagenetic and textural characteristics, belonging to the Araripe, Potiguar and Sergipe - Alagoas basins. Of these, 14 are limestones, 2 of tufa limestone, 2 of caliche and 1 of dolomite. In the laboratory a gas permoporosimeter was used to measure the porosity and permeability parameters. µCT samples were obtained with a resolution of about 2.0 μm. The set of images created was treated in Avizo Fire software and the porosity, permeability, connectivity and pore diameter parameters were extracted. A statistical model was established to predict permeability from pore space parameters extracted from µCT images. The results indicate that the connectivity of micropores, inferred from the calculation of the Euler Number in 3D images, is the parameter that exerts the greatest influence in the estimation of permeability, followed by the porosity of the macropores and the connectivity of the macropores. The proposed predictive model presented a coefficient of determination of 0.994, being very reliable for the group of samples investigated.

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JUNIOR, EDGARD POIATE. "ROCK MECHANICS AND COMPUTATIONAL MECHANICS FOR THE DESIGN OF OIL WELLS IN SALT ZONES." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2012. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=34904@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
O objetivo deste estudo foi ampliar o conhecimento em mecânica de rochas evaporíticas e aplicar a mecânica computacional na modelagem numérica do comportamento estrutural de poços de petróleo em zonas de sal. Amostras de rochas evaporíticas de anidrita, halita, carnalita e taquidrita pertencentes à sequência evaporítica Ibura da Formação Muribeca, testemunhadas em poços de petróleo, foram submetidas a ensaios laboratoriais de mecânicas de rochas, em especial a ensaios triaxiais de fluência sob diferentes condições de estado de tensões e temperaturas. Nas mesmas condições de ensaio triaxial de fluência a taquidrita desenvolveu deformação axial específica de cerca de 107 vezes maior que a halita e 2,7 vezes maior que a carnalita, sendo que a anidrita permanece essencialmente indeformável. Para os ensaios triaxiais de fluência com a halita na temperatura de 86 graus Celsius foi possível definir o mecanismo duplo de deformação por fluência, enquanto que para a carnalita e a taquidrita isto ocorreu nas temperaturas de 130 e 86 graus Celsius, respectivamente. A taxa de deformação por fluência em regime permanente obtida por simulação numérica reproduziu fielmente os resultados experimentais dos ensaios triaxias de fluência, com erro relativo inferior a 1 por cento. Através dos ensaios laboratoriais foram obtidos os parâmetros geomecânicos de fluência das rochas ensaiadas e a seguir aplicados nos modelos numéricos de simulação, construídos para avaliar a influência de diversos parâmetros nos estudos de estabilidade de poços e integridade de revestimentos. A desconsideração da interação geomecânica entre estruturas salíferas e o maciço hospedeiro pode conduzir a falhas na perfuração de poços próximos a tais estruturas devido ao processo de halocinése do sal que altera o estado de tensões gravitacional.
The aim of this study was to increase knowledge of evaporitic rock mechanics and apply computational mechanics in numerical modeling of structural behavior of oil wells in areas of salt. Evaporitic rock samples of anhydrite, halite, carnallite e tachyhydrite and belonging to the evaporitic sequence Ibura from the Muribeca formation, coring in oil wells, were subjected to laboratory tests of rock mechanics, especially the triaxial creep under different states of stress and temperature. Under the same conditions of triaxial creep tachyhydrite developed specific axial strain rate about 107 times that of halite and 2.7 times that of carnallite, and anhydrite remains essentially undeformed. For the triaxial creep of halite in the temperature of 86 degrees Celsius it was possible to define the double mechanism creep law, while for carnallite and tachyhydrite this occurred at temperatures of 130 and 86 degrees Celsius, respectively. The creep rate in steady state condition obtained by numerical simulation accurately reproduced the experimental results of the triaxial creep tests, with a relative error less than 1 percent. Through laboratory tests geomechanical creep parameters of the tested rocks were obtained and then applied in numerical simulation models, designed to evaluate the influence of various parameters in the well stability and casing design. The lack of consideration of the geomechanical interaction between the salt structures and the host rock can lead to drilling failures in wells near such structures due to the salt halokinesis process that changes the gravitational stress state.

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Mendez, Casal M. J. "Changes in rock mechanics properties due to formation damage." Thesis, Heriot-Watt University, 2004. http://hdl.handle.net/10399/357.

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Rehermann, Pablo F. Sanz. "Modeling rock folding with large deformation frictional contact mechanics /." May be available electronically:, 2008. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.

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Mighani, Saied 1989. "Some rock mechanics problems with application for hydraulic fracturing." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122224.

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Thesis: Ph. D. in Geophysics, Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2019
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 185-205).
Hydraulic fracturing is an essential tool used to enhance connectivity in shale gas reservoirs by maximizing the intersection between the hydraulic fracture (HF) and pre-existing natural fractures (NF) or faults. The technique is most effective when the hydraulic fracture crosses natural fractures rather than arresting on them. Experiments conducted to examine the interaction between HF and artificial pre-existing faults suggest that the coupling of diffusivity and fault slip is an important element of the HF-fault interaction problem. Fault slip, once activated is associated with an apparent increase in diffusivity. Whether the hydrofracture crosses or arrests on the pre-existing fault is also affected by surface roughness, differential stresses, and fault slip mode (i.e., stable or stick-slip sliding). Calibrated piezoelectric transducers were used to measure acoustic emissions (AE) generated during HF and fault slip.
Moment tensor analysis of these events was used to distinguish pure tensile, shear, and possibly closure events during the experiments. Seismic moment magnitudes were approximately -7 for events during the initiation of the HF and about -5 for events during fault slip. Such a low ratio of seismic moments for tensile and slip events may explain the small numbers of tensile events recorded during reservoir stimulations. I also studied the time-dependent behavior in shales to gain insight into the post-stimulation efficiency of exploitations. Shale experiences strain hardening and compaction during loading by both isostatic (pressure-driven) and differential stress (shear-driven). Transient creep strain increased linearly with log(time), possibly transitioning to constant rate in timescale of several days. Motivated by the multi-scale nature of heterogeneities in shales, I examined the micromechanics of deformation using the nano-indentation technique.
Elastic and creep moduli found in nano-indentation and triaxial tests agreed within a factor of 2, but within that factor, the creep strength may depend on spatial scale.
by Saied Mighani.
Ph. D. in Geophysics
Ph.D.inGeophysics Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences

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Peck, Jonathan Philip. "Application of drill monitoring to rock mass characterization." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65440.

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Ma, Sang Joon. "Design of underground storage caverns in weak rock." Thesis, University of Leeds, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275848.

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Jackson, Richard Robert. "Geometries and mechanics of veins and dykes." Thesis, University of Southampton, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385102.

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Felton, David Scott. "Theoretical dissolution coefficient for rock fractures." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/21505.

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Wong, Wing-yee, and 黃詠儀. "Permeability studies in rock fractures." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B43895013.

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Liu, Chi-hong, and 廖志航. "Base friction modelling of discontinuous rock masses." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B42577123.

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Collingwood, Benjamin. "The effects of construction practices on the performance of rock socketed bored piles." Online version, 2000. http://bibpurl.oclc.org/web/25062.

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Ikegawa, Yojiro. "Three-dimensional geometrical analysis of rock mass structure." Thesis, Imperial College London, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294135.

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Dyke, Christopher George. "In situ stress indicators for rock at great depth." Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/8231.

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Meyers, Anthony G. "The determination of rock mass strength for engineering design /." Title page, contents and abstract only, 1993. http://web4.library.adelaide.edu.au/theses/09PH/09phm6134.pdf.

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Cheng, Pei-fen Caral. "Project report on direct shear tests for rock joints." Click to view the E-thesis via HKUTO, 2002. http://sunzi.lib.hku.hk/hkuto/record/B42576659.

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Benson, Carl Philip. "Literature review of rock properties for analysis of navigation structures founded on rock." Thesis, Virginia Tech, 1986. http://hdl.handle.net/10919/45747.

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A review of behavioral rock properties used for input to the finite element method are summarized. Rock properties presented in the literature were primarily obtained from laboratory specimens. Methods to determine applicable field properties via testing, calculations and empirical correlations are included. Suggested behavioral properties of the structural concrete-to-rock interface are proposed. Specific property values, resulting from the literature review, are presented as input for a finite element parametric evaluation of navigation structures.
Master of Science

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Soroush, Hamed. "A data processing workflow for borehole enlargement identification and characterisation using petrophysical logs." Thesis, Curtin University, 2009. http://hdl.handle.net/20.500.11937/771.

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Borehole breakouts provide valuable information with respect to the evaluation of the in-situ stress direction and magnitude, and also verification of any geomechanical models built for a specific field. Identifying the locations along a borehole where the breakouts form is therefore very important. On the other hand, the borehole geometry (defined as width and depth of breakouts), which is a critical factor in completion and production optimisation design, can also be estimated from the back analysis of breakout information. While breakout width has been widely used in obtaining an estimate of the maximum horizontal stress magnitude, few studies have been reported on the estimation of breakout depth and the information it may provide.Caliper and image logs are customarily used to identify and characterise borehole enlargement zones; in particular, the breakouts. However, these methods are limited in their applications in many instances. In addition, good quality image logs are not available in many wells including old wells. This leads to a need for the development of a new approach to identify the location of borehole enlargements along a wellbore.This research aims to understand the mechanisms under which breakouts form with respect to a rock’s physical and mechanical properties. Petrophysical logs, which are often acquired in most of the drilled wells, show correlations with mechanical properties of the rock. Therefore, this research attempts to develop an approach to identify the location of borehole enlargement zones using the information gained from petrophysical logs.This research introduces a new multi-variable approach based on various data processing techniques (including wavelet, classifiers, and neural networks) to extract rock properties from different petrophysical logs. This information was combined using a robust data fusion technique which determined the location of the enlarged borehole. The results demonstrated the accuracy of the location of the borehole enlargement identified along a borehole compared to that observed using calipers and image logs.In addition, there were correlations between breakout width and depth measurements when measurements taken from high quality acoustic image logs were used. Elastic and elastoplastic finite element numerical models also showed how breakout width and depth could change due to a change in different rock properties. The models were verified by comparing results of numerical analysis with real observations from field data.

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Gamboa, Erwin. "Stress corrosion cracking of rock bolts /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18302.pdf.

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Scheldt, Therese. "Comparison of continuous and discontinuous modelling for computational rock mechanics." Doctoral thesis, Norwegian University of Science and Technology, Department of Geology and Mineral Resources Engineering, 2003. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-943.

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Computational rock mechanics becomes more and more popular. New programs are constantly under development, and the modelling process has become a natural part of the planning process for many caverns and tunnels, as well as for the mining and petroleum industry.

When to use continuous modelling in preference to discontinuous modelling and vice versa, is an important question that has been discussed for a long time.

For this purpose, in this work continuous and discontinuous modelling is applied in order to analyze the stability of the Gjøvik Olympic Mountain Hall. The large span cavern (62m) was built in connection with the XVII Winter Olympic Games 1994 at Lillehammer, and is a unique case study because of the large amount of available input data from a comprehensive stress and deformation monitoring program carried out during and after the excavation, as well as thorough pre-investigations. Phase2, a two-dimensional non-linear finite element program, and the Discontinuous Deformation Analysis (DDA) are used as representative tools for continuous and discontinuous modelling, respectively. DDA is both a theory and a computer program. The modelling procedure is similar to the distinct element modelling, while it more closely parallels the finite element method with respect to: i) Minimizing the total potential energy to establish equilibrium equations, ii) Choosing displacements as unknowns of the simultaneous equations and iii) Adding stiffness, mass and loading submatrices to the coefficient matrix of the simultaneous equation.

In general, the decision to use either continuous or discontinuous modelling should be based on data from the geological field mapping process. Mapping techniques which remove subjectivity from the results, for example scanline/area mapping or semi-automatic mapping, are recommended. If the rock mass is basically free of discontinuities, or if the discontinuities are very closely spaced in comparison to the dimensions of the problem to be analysed, continuous modelling is preferable. If large deformations including slip, rotation and separation are dominant, as for rock slope stability problems, discontinuous modelling may be selected. If the problem to be analysed cannot be classified within one of the two groups, the quality of required input parameters and the purpose of the modelling should be taken into consideration.

For underground hard rock problems as the Gjøvik Olympic Mountain Hall, continuous modelling is strongly recommended. Today’s mapping techniques are not good enough to give satisfactory information about the required and most crucial input for discontinuous modelling, namely the joint pattern, and the process for implementation of measured discontinuities into a numerical model is based on too many approximations. In addition, the discontinuous modelling process is very time consuming. A fast and high capacity computer is required.

Crucial input parameters for continuous modelling are strength and deformability parameters of the rock mass, and estimation of these parameters is dependent on the selected failure criterion, usually either Mohr-Coulomb or Hoek-Brown.

The magnitude of in-situ stresses, particularly the horizontal stresses, may have crucial influence on the general stability, and independent of whether continuous or discontinuous modelling is selected, in-situ stress measurements are strongly recommended in order to estimate a reasonably correct stress level for the problem to be analysed.

It is very difficult to estimate reliable input parameters for numerical modelling and a critical evaluation of the analysis results is absolutely recommended. Thus, analysis results should be considered as valuable additional input to field observations, in-situ and laboratory measurements, and experience rather than a precise answer for the given problem.

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Butterworth, Simon Richard. "Anelastic strain recovery of rock core and crustal stress measurements." Thesis, University of East Anglia, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.482046.

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Gumusoglu, M. Cetin. "Analysis of underground excavations in strain softening rock masses." Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/38339.

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Cheng, Pei-fen Caral, and 鄭佩芬. "Project report on direct shear tests for rock joints." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B42576659.

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Leung, Wai-ming Eric. "Re-assessment of three rock slopes in Hong Kong using block theory." Click to view the E-thesis via HKUTO, 2004. http://sunzi.lib.hku.hk/hkuto/record/B42577640.

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Fahimifar, Ahmad. "Experimental investigations on the mechanical properties of rocks containing a single discontinuity." Thesis, University of Newcastle upon Tyne, 1990. http://hdl.handle.net/10443/3603.

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An extensive experimental programme was undertaken to investigate the strength and deformational characteristics of six rock types containing a single joint under various loading and straining conditions. A monitoring system was set up using a microcomputer controlled logger and the required computer programs for data logging and processing were also developed. For the purpose of achieving reliable findings the effects of system constraints on the experimental results in triaxial testing of jointed specimens were investigated. On the basis of a satisfactory end-specimen condition the results of triaxial compressive tests performed on the specimens of three rock types, containing artificial joints at different orientations, are presented, and the effects of joint inclination, confining pressure (0-70 MPa) and joint surface roughness on the mechanical behaviour of jointed specimens were investigated. A method to calculated volumetric strain in the rock specimens has been developed and the volumetric strain, lateral strain and instantaneous Poisson's ratio for both intact and jointed specimens are calculated. Time-dependency of jointed rocks for the three cases of different constant strain rates, changing strain rates and stress relaxation at various points on the complete stress-strain curve has examined. The failure criteria applicable to jointed media are reviewed and the necessary parameters for an appropriate failure criterion have been defined. The stick-slip characteristics of jointed rocks are investigated and two types of stick-slip phenomena are introduced in conjunction with the type of rock and type of testing system.

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Yaghoobi, Rafi Jalaleddin. "Study of Pumping Pressure and Stop Criteria in Grouting of Rock Fractures." Doctoral thesis, KTH, Jord- och bergmekanik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-155323.

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Today practice of grouting is based on empirical approaches in that, pumping pressure and stop criteria are determined by benchmarking similar projects. Considering a maximum limit for grouting pressure would allow applying a relatively high pressure that may lead to jacking of the fracture or even uplift of the rock mass. On the other hand, keeping the pressure lower than the overburden, in order to avoid any deformation, will prolong grouting process. Determination of pumping pressure is more complicated considering the induced energy to the rock fracture due to combination of the injected volume and pumping pressure. In other word, pressurizing large volume of the injected grout with a low pumping pressure establish the same force inside the fracture as the high applied grouting pressure on small injected volume do. Therefore, an stop criterion to limit grouting volume along with grouting pressure, which is a hyperbola trimming maximum pressure-maximum volume limits and named as grout intensity number (GIN), has been defined. However, in using this stop criterion and at completion point, the state of the fracture and the distance that grout spread inside the fracture are unknown. As a theoretical approach, examining the flow of the Bingham fluid in network of fractures led to development of a numerical model and later an analytical solution, which enabled estimation of distance that grout spread in the fractures in real time. Finally, theoretical curves to limit elastic and ultimate jacking were established to limit grout pressure in correlation with depth of grout penetration by considering the state of the fracture. Despite empirical and theoretical developments, determination of optimum grouting pressure is still challenging. In this study, In addition to examining performance of the analytical solution in estimation of grout spread and distinguishing onset of fracture jacking, the goal is coming up with recommendations for selection of optimum grouting pressure, by examining mechanism of elastic jacking. For this purpose, negative aspects of fracture deformation, which are increase of grouting time and remaining transmissivity, were quantified and discussed against its positive effect on increase of penetrability. By that, application of a relatively high pressure was recommended in order to opening of the fracture to a permitted level, with purpose of increasing penetrability while considering negative effects of elastic jacking. The stop criterion is defined as the grouting time of achieving the required distance of grout spread at the highest applicable grouting pressure. In examining empirical methods, in grouting of fractures in deep levels, pressure-depth graph suggests usage of higher pressure in compare with the estimated pressure by theory while GIN method is conservative. In further studies GIN was estimated analytically and applying a relatively high grouting pressure in order to opening the fracture, up to attaining the hyperbola, and continuation of grouting with decreasing trend, in order to bringing the fracture back to its initial size at refusal, were proposed. Complexity of using this methodology in compare with theoretical approach was discussed. As the future work, there is a need to verify the results in the field, and to confirm well performance of this analytical solution in different geologies. Examining variation of grout mixture properties during grouting program as well as significance of simplification of geological pattern to a single horizontal fracture, in that grout flow radially, are among other future studies that can develop this theoretical application further.

QC 20141106

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Zhao, Jianping. "An investigation into the rheological behaviour of rock salt with application to the design of underground structures." Thesis, University of Newcastle Upon Tyne, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385707.

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Beesley, M. L. G. "An investigation of wellbore stability using numerical and physical modelling." Thesis, University of Newcastle Upon Tyne, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254203.

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Taylor, J. A. "Potential stability and subsidence issues arising from abandoned bord-and-pillar coal workings." Thesis, University of Leeds, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275437.

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McConnell, Brian James. "Factors controlling sandstone strength and deformability in uniaxial compression." Thesis, University of Bristol, 1989. http://hdl.handle.net/1983/2fde6a20-8069-4e9e-beb9-2c0b867385de.

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Dissertations / Theses on the topic 'Petrophysics and rock mechanics'

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