Study of CO₂ mobility control using cross-linked gel conformance control and CO₂ viscosifiers in heterogeneous media /
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| Other Authors: | |
| Format: | Thesis eBook |
| Language: | English |
| Published: |
[College Station, Tex.] :
[Texas A&M University],
[2011]
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| Subjects: | |
| Online Access: | Link to OAK Trust copy |
| Abstract: | CO₂ has been widely used as a displacement fluid in both immiscible and miscible displacement processes to obtain tertiary recovery from the field. There are several problems associated with the application of CO₂ flooding, especially when there is a significant presence of heterogeneous elements, such as fractures, channels and high permeability streaks within the reservoir. With flooding, CO₂ will finger through the target zone while leaving most of the residual/trapped oil untouched. As a result, early gas breakthrough has been a very common problem in CO₂-related projects, reducing the overall sweep efficiency of CO₂ flooding. This research aims at improving the CO₂ flood efficiency using cross-linked gel conformance control and CO₂ viscosifier technique. A series of coreflood experiment studies have been performed to investigate the possibility of applying CO₂ mobility control techniques. Corresponding simulation works have also been carried out to predict the benefits of applying CO₂ mobility control techniques in the field. In the laboratory study, the CO₂ coreflood system was integrated with the CT (Computed Tomography)-scanner and obtained real-time coreflood images of the CO₂ saturation distributions in the core. This system was applied to the research of both cross-linked polymer gel treatment and CO₂ viscosifier study and produced images with sharp phase contrasts. For the gel conformance study, promising results were obtained by applying cross-linked gel to eliminate permeability contrast and diverting CO₂ into low permeability regions to obtain incremental oil recovery; also studied were the gel strength in terms of leak-off extent with the aid of CT (Computed Tomography) images. For the CO₂ viscosifier research, we tested several potential viscosifier chemicals and found out PVAc (Polyvinylacetate)/toluene combination to be the most promising. The follow-up study clearly demonstrates the superiority of viscosified CO₂ over neat CO₂ in terms of sweep efficiency. This research serves as a preliminary study in understanding advanced CO₂ mobility control techniques and will provide insights to future studies on this topic. |
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| Item Description: | "Major Subject: Petroleum Engineering" Title from author supplied metadata (automated record created 2011-11-01 09:04:20). Electronic resource. |
| Physical Description: | 1 online resource. |
| Bibliography: | Includes bibliographical references. |