Literatura académica sobre el tema "Bridge clogging"

This chapter examines the use of dance to promote community development at Hoedown Island, Eastern Kentucky, with particular emphasis on the role played by the Natural Bridge State Resort Park in Powell County. It begins with an overview of the Natural Bridge State Resort Park and the efforts of civic leaders like Richard Jett to make life better for Powell and other nearby counties. It then considers Natural Bridge's role in the promotion of dancing at Hoedown Island under Jett's leadership, along with the importance of an intergenerational community and a spirit of cooperation in making dance a key part of his vision for Hoedown and for the entire Appalachian region more generally. It also discusses the ways that individual expression was encouraged in dancing such as freestyle clogging and how Jett's goal of promoting the region and its talents intersected with the national interest in Appalachian culture. The chapter concludes with an assessment of the Hoedown Island Cloggers's performance in 2000 as well as Jett's legacy and future prospects for dance at Hoedown Island.

The composition of sewage water with partially large portions of fibers and solids requires a special pump design, in order to avoid operational disturbances by clogging. In most applications for sewage water transport, single-stage pumps with single-blade impellers are used. With this special impeller geometry largest flow channels can be realized. So fibers and solids up to an appropriate size can be transported by the pump. This minimum impeller blade number however brings disadvantages for pump operation. The development of a pressure and a suction surface of the blade gives an asymmetric pressure distribution at the perimeter of the rotor outlet and a periodically unsteady flow field arises. In a numerical approach the time accurate flow in a single-blade centrifugal pump has been calculated by solving the 3-dimensional time dependent Reynolds averaged Navier-Stokes equations (URANS) in a wide range of pump operation. The investigation of the flow included all details between suction flange and pressure flange of the pump. The numerical results show a strong dependence from impeller position for all flow parameters. For the investigated operating points strong vortices have been obtained at particular impeller positions. Experimental results have been used to verify the numerical results of time dependent flow in the single-blade pump. The computed flow field has been compared to results which were obtained from optical measurements of flow velocities by Particle Image Velocimetry at different impeller positions. A very good qualitative agreement between measurements and calculations has been obtained for all investigated operating points.

The transport of fluids which include a lot of impurities is often done by special single-stage pumps. In order to avoid clogging of the pumps, the impellers have only one blade. This minimum blade number brings strong disadvantages during the pump operation. The rotation of the impeller in the pump casing produces a strongly uneven pressure field along the perimeter of the casing. The resulting periodically unsteady flow forces affect the impeller and produce radial deflections of the pump shaft which can be recognized as vibrations at the bearing blocks or at the pump casing. These vibrations will also be transferred to the pump casing and attached pipes. In a numerical approach the hydrodynamic excitation forces of a single-blade pump were calculated from the time dependent flow field. The flow field is known from the numerical simulation of the three-dimensional, viscous, unsteady flow in the pump by using a commercial computer code determining the Reynolds averaged Navier-Stokes equations (URANS). The periodically unsteady flow forces were computed for a complete impeller revolution. This forces affect the rotor of the pump and stimulate it to oscillations. The computed forces were defined as external forces and applied as the load on the rotor for a structural analysis. The resulting oscillations of the rotor were calculated by a transient analysis of the rotors structure using a commercial FEM-Method. To verify the calculated results, experimental investigations have been performed. The deflections of the pump rotor were measured with proximity sensors in a wide range of pump operation. Measurements of the vibration accelerations at the pump casing showed the visible effects of the transient flow. To minimize the vibration amplitudes the energizing forces have been reduced by attaching a compensation mass at the impeller. This procedure can be used as “operational balancing” of the pump rotor for a certain point of operation.

Abstract One of the main risks of CO2 injection into sedimentary formations, especially saline aquifers, is well clogging due to salt precipitation. Capillary-driven backflow of formation brine may serve as a continuous transport of dissolved salt toward the dry zone around the injection point. This salt will eventually precipitate due to water vaporization, jeopardizing the CO2 injectivity. The study objective is to apply to a potential CO2 storage complex, constituted by a multi-layered depleted gas field, a multi-step, mineralogical-geochemical workflow emphasizing the role of capillary-driven transport of dissolved salt on CO2 injectivity. An integrated workflow, starting from real samples, and coupling laboratory activities with numerical simulations, is given. The workflow consists of the following steps: Lithological, mineralogical, and geochemical characterization of field core samples Laboratory ageing experiments on caprock samples with CO2 Preliminary geochemical numerical models’ calibration to reproduce the results of CO2 ageing experiment Geochemical numerical modelling at different spatial/temporal scales and complexity levels The CO2 injection is simulated via multi-layered 2D radial reactive transport model. The CO2 injection scheme and the pressure buildup have been maintained as per field 3D dynamic model. The formation brine chemical composition is retrieved from laboratory analysis. The mineral dissolution/precipitation and CO2 dissociation reactions are modelled using a rate-dependent and an equilibrium approach respectively. The overall mineralogical composition can be defined as highly heterogeneous due to the presence of not-negligible amounts of quartz, feldspar, mica, clay, and carbonate minerals. The latter are more present in the caprock (around 45% wt.) and less in the reservoir samples (15% wt.). The ageing experiment performed using caprock samples resulted in partial Calcite mineral dissolution in the presence of CO2-rich water and allowed to better calibrate parameters used for numerical geochemical modelling activities. The simulations at reservoir conditions show a limited dissolution of calcite due to the pH lowering associated to the CO2 plume evolution, and water vaporization phenomenon is observed in the near wellbore area. The effect of capillary-driven back flow is acknowledged by comparing the water movements in the near wellbore area with and without the capillary pressure. The capillary-driven back flow has shown a limited impact on Halite precipitation around the injection well, even when the capillary pressure is doubled. Further simulation work has been performed to check whether the conclusions are still applicable even in the worst-case scenario where Halite precipitation is instantaneously modelled via an equilibrium approach instead of a kinetic one. The presented workflow gives a new perspective in geochemical application for CO2 storage studies, which increases the reliability and specificity of the investigation via a strong integration between experimental analyses and numerical modelling.

Abstract Objectives/Scope Controlling the excessive water production from the high water cut gravel packing horizontal well is a challenge. The approach which uses regular packers or packers with ICD screens to control the unwanted water does not function well. This is mainly because of the length limitation of packers which will make the axial flow resistance insufficient. Methods, Procedures, Process In this paper, a successful case that unwanted water is shutoff by using continuous pack-off particles with ICD screens (CPI) in the whole horizontal section in an offshore oilfield of Bohai bay is presented. The reservoir of this case is the bottom-water high viscosity reservoir. The process is to run 2 3/8" ICD screen string into the 4" screen string originally in place, then to pump the pack-off particles into the annulus between the two screens, and finally form the 360m tightly compacted continuous pack-off particle ring. Results, Observations, Conclusions The methodology behind the process is that the 2-3/8" ICD screens limit the flow rate into the pipes as well as the continuous pack-off particle ring together with the gravel ring outside the original 4" screens to prevent the water channeling into the oil zone along the horizontal section. This is the first time this process is applied in a high water cut gravel packed horizontal well. After the treatment, the water rate decreased from 6856BPD to 836.6BPD, the oil rate increased from 44BPD to 276.8BPD. In addition, the duration of this performance continued a half year until March 21, 2020. Novel/Additive Information The key of this technology is to control the unwanted water by using the continuous pack-off particles instead of the parkers, which will bring 5 advantages, a) higher efficiency in utilizing the production interval; b) no need to find the water source and then fix it; c) the better ability to limit the axial flow; d) effective to multi-WBT (water break though) points and potential WBT points; e) more flexible for further workover. The technology of this successful water preventing case can be reference to other similar high water cut gravel packed wells. Also, it has been proved that the well completion approach of using CPI can have good water shutoff and oil incremental result. Considering the experiences of historical applications, CPI which features good sand control, water shutoff and anti-clogging is a big progress compared to the current completion technologies.

Abstract Polymer flooding projects require hundreds of ppm of polymer (often HPAM) to viscosify the injection water. It is well known that the required dose of HPAM to obtain a targeted viscosity will decrease by reducing the salinity of the inlet water. When the water salinity is low enough, desalination of water for reducing the required polymer concentration brings effective cost savings. In a scenario where the produced water has a salinity of 6 g/L, desalination of this water down to 1 g/L before polymer injection would reduce by half polymer consumption (from 1300 ppm down to 700 ppm). Such low salinity can be found in many existing polymer flooding projects in sandstones reservoirs. A lower concentration of polymer leads to significant reductions of CAPEX (storage tank, pump size) and OPEX (polymer cost, transport and handling). But there are also indirect advantages and cost savings impact of low incoming Polymer concentration in polymer flooding projects. Polymer flooding technology increases and accelerates the oil production by a so-called piston effect pushing an oil bank and enhancing conformance in the reservoir. But there are issues relative to polymer production such as lower separation efficiency, thermal clogging of the polymer in the heat exchangers and poor performance of produced water treatment due to the presence of polymer. It was proven that the impact on water treatment performance is directly related to the concentration of polymer in the produced water. To reduce this impact, existing technical solutions (such as mechanical or chemical degradation, separation by centrifugation) are costly. The presence of polymer is very detrimental to any filtration technologies (membrane fouling) and therefore Oil in Water reduction below 20 ppm is becoming challenging. Waiting for suitable cost effective water treatment technologies, existing polymer flooding projects have adopted a different strategy aiming at reducing or stopping polymer solution injection when the back produced polymer concentration was about to reach a limit known to impact the existing water treatment. Using the EDR technology to reduce required polymer concentration will thus reduce the back produced polymer concentration and could allow the existing water treatment technologies to handle back produced polymer without additional modification and cost. EDR adaptation to desalination of produced water in presence of polymer, dispersed oil, and production chemicals was performed by Total, MemBrain and MEGA. The development of suitable membrane and stack withstanding up to 80°C was engineered by MemBrain and tested during a few weeks on synthetic produced water on a semi-industrial scale pilot treating 10 m3/h synthetic water (in closed loop) with an EDR stack containing 29.2 m2 membrane area. After a few reference tests for characterizing the EDR stack performances, the pilot was operated during 1 month in presence of a salt matrix representative of the case study: 6 g/l of salt, 600 mg/l HPAM polymer, 20 mg/L crude oil, 50 mg/L corrosion inhibitor and 20 mg/l anti-scalant. Voltage was set at 1 V/pair (100 V). The temperature was set at 60°C with no impact on the membrane stack reliability during the test. The presence of HPAM slightly decreases desalination rate but no fouling was observed. Cost and environmental evaluations showed that EDR improves all the indicators. The total technical cost of the project is lower with EDR (CAPEX higher but lower OPEX) compared to a base case without any desalination. The next step is to qualify the technology on a site pilot with real produced water.