Experimental and simulation studies of sequestration of supercritical carbon dioxide in depleted gas reservoirs /
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| Other Authors: | , |
| Format: | Thesis eBook |
| Language: | English |
| Published: |
[College Station, Tex.] :
[Texas A&M University],
[2004]
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| Subjects: | |
| Online Access: | Link to OAK Trust copy |
| Abstract: | Experimental, analytical, and simulation studies have been conducted to evaluate the feasibility of sequestering supercritical CO₂ in depleted gas reservoirs. The experimental runs involved the following steps. First, the 1 ft long by 1 in. diameter carbonate core is inserted into a viton Hassler sleeve and placed inside an aluminum coreholder that is then evacuated. Second, with or without connate water, the carbonate core is saturated with methane. Third, supercritical CO₂ is injected into the core with 300 psi overburden pressure. From the volume and composition of the produced gas measured by a wet test meter and a gas chromatograph, the recovery of methane at CO₂ breakthrough is determined. The core is scanned three times during an experimental run to determine core porosity and fluid saturation profile: at start of the run, at CO₂ breakthrough, and at the end of the run. Runs were made with various temperatures, 20 ʻC (68 ʻF) to 80 ʻC (176 ʻF), while the cell pressure is varied, from 500 psig (3.55 MPa) to 3000 psig (20.79 MPa) for each temperature. An analytical study of the experimental results has been also conducted to determine the dispersion coefficient of CO₂ using the convection-dispersion equation. The dispersion coefficient of CO₂ in methane is found to be relatively low, 0.01-0.3 cm2/min.. Based on experimental and analytical results, a 3D simulation model of one eighth of a 5-spot pattern was constructed to evaluate injection of supercritical CO₂ under typical field conditions. The depleted gas reservoir is repressurized by CO₂ injection from 500 psi to its initial pressure 3,045 psi. Simulation results for 400 bbl/d CO₂ injection may be summarized as follows. First, a large amount of CO₂ is sequestered: (i) about 1.2 million tons in 29 years (0 % initial water saturation) to 0.78 million tons in 19 years (35 % initial water saturation) for 40-acre pattern, (ii) about 4.8 million tons in 112 years (0 % initial water saturation) to 3.1 million tons in 73 years (35 % initial water saturation) for 80-acre pattern. Second, a significant amount of natural gas is also produced: (i) about 1.2 BSCF or 74 % remaining GIP (0 % initial water saturation) to 0.78 BSCF or 66 % remaining GIP (35 % initial water saturation) for 40-acre pattern, (ii) about 4.5 BSCF or 64 % remaining GIP (0 % initial water saturation) to 2.97 BSCF or 62 % remaining GIP (35 % initial water saturation) for 80-acre pattern. This produced gas revenue could help defray the cost of CO₂ sequestration. In short, CO₂ sequestration in depleted gas reservoirs appears to be a win-win technology. |
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| Item Description: | "Major Subject: Petroleum Engineering" Title from author supplied metadata (record created on Nov. 30, 2005.) Vita. Abstract. Electronic resource. |
| Physical Description: | 1 online resource. |
| Format: | System requirements: Adobe Acrobat Reader. |
| Bibliography: | Includes bibliographical references. |