Browsing by Subject "gel"
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Item Application of Polymer Gels as Conformance Control Agents for Carbon Dioxide for Floods in Carbonate Reservoirs(2012-10-15) Al Ali, Ali 1986-With the production from mature oil fields declining, the increasing demand of oil urges towards more effective recovery of the available resources. Currently, the CO2 Floods are the second most applied EOR processes in the world behind steam injection. With more than 30 years of experience gained from CO2 flooding, successful projects have showed incremental oil recovery ranging from 7 to 15 % of the oil initially in place. Despite all of the anticipated success of CO2 floods, its viscosity nature is in heterogeneous and naturally fractured reservoirs is challenging; CO2 will flow preferentially through the easiest paths resulting in early breakthrough and extraction ineffectiveness leaving zones of oil intact. This research aims at investigating gel treatments and viscosified water-alternating-gas CO2 mobility control techniques. A set of experiments have been conducted to verify the effectiveness and practicality of the proposed mobility control approaches. Our research employed an imaging technique integrating an X-Ray CT scanner with a CT friendly aluminum coreflood cell. With the integrated systems, we were able to obtain real time images when processed provide qualitative and qualitative evaluations to the coreflood. The research studies included preliminary studies of CO2 and water injection performance in fractured and unfractured cores. These experiments provided a base performance to which the performances of the mobility control attempts were compared. We have applied the same methodology in evaluation of the experimental results to both conformance control gel treatments and viscosified water-alternating-gas CO2 mobility control. The gel conformance control studies showed encouraging results in minimizing the effect of heterogeneities directing the injected CO2 to extract more oil from the low permeability zones; the gel strength was evaluated in terms of breakdown and leakoff utilizing the production data aided with CT imaging analysis. The viscosified water coupled with CO2 investigations showed great promising results proving the superiority over neat CO2 injection. This research serves as a preliminary understanding to the applicability of tested mobility control approaches providing a base to future studies in this category of research.Item Deep Placement Gel Bank as an Improved Oil Recovery Process: Modeling, Economic Analysis and Comparison to Polymer Flooding(2011-08-08) Seyidov, MuradMany attempts have been made to control water conformance. It is very costly to produce, treat and dispose of water, and produced water represents the largest waste stream associated with oil and gas production. The production of large amounts of water results in: (a) the need for more complex water?oil separation; (b) corrosion of wellbore and other equipment; (c) a rapid decline in hydrocarbon production rate and ultimate recovery; and (d) consequently, premature abandonment of a well or field, leaving considerable hydrocarbons unproduced. Sometimes water production results from heterogeneities in the horizontal direction, which leads to uneven movement of the flood front and subsequent early breakthrough of water from high permeability layers. This problem is exacerbated if there is (vertical) hydraulic communication between layers so that crossflow can occur. One of the novel technologies in chemical enhanced oil recovery (EOR) is a gel type called deep diverting gel (DDG), which describes material that functions by plugging thief zones deep from the well where they were being injected. To evaluate the performance of this new treatment method, we will (1) model the treatment methods, (2) conduct economic analysis, and (3) compare different EOR methods. We have conducted relevant literature review about the development, design, modeling and economics of the enhanced oil recovery methods. Schlumberger's Eclipse simulator software has been used for modeling purposes. Modeling runs have demonstrated that placement of a DDG in a high permeability zone provided a blockage that diverted water into lower permeability areas, thus increasing the sweep of target zones. Research results demonstrated that, although higher recovery can be achieved with a polymer flood, the combination of delayed production response and large polymer amounts cause such projects to be less economically favorable than deep gel placement treatments. From results of several sensitivity runs, it can be concluded that plug size and oil viscosity are two determining factors in the efficiency of DDG treatments. For the assumed case, economic analysis demonstrated that DDG has the most positive net present value (NPV), with polymer flooding second and simply continuing the waterflood to its economic limit the least positive NPV.