Currently, the Water-Alternating-Gas (WAG) process is the most widely practiced horizontal mode gas injection process in the industry. Although this process is conceptually sound, it has resulted in low (5 10%) oil field recoveries. Conversely, the gravity stable mode of gas injection has carved its niche as one of the most effective methods of gas injection EOR in the dipping reservoirs and pinnacle reefs. The Gas Assisted Gravity Drainage (GAGD) process is therefore being developed at LSU to extend these highly successful gravity stable applications to horizontal type reservoirs.
The dissertation attempts to address six key questions: (i) do we continue to fix the problems of gravity segregation in the horizontal gas floods or find an effective alternative?, (ii) is there a happy-medium between single-slug and WAG processes that would outperform both?, (iii) what are the controlling multiphase mechanisms and fluid dynamics in gravity drainage processes?, (iv) what are the mechanistic issues relating to gravity drainage?, and (v) how can we model the novel GAGD process using traditional analytical and empirical theories and (vi) what are the roles of the classical displacement, versus drainage in the GAGD process?
The original contributions of this work to the existing literature are summarized as: (i) first demonstration of the GAGD concept through high pressure experimentation, (ii) experimental demonstration of the superior oil recovery performance of the GAGD process in secondary (immiscible recovery range: 62.3% to 88.56% ROIP) and tertiary (immiscible recovery range: 47.3% to 78.9% ROIP) processes, in both miscible (avg. secondary and tertiary miscible recoveries: near 100% ROIP) and immiscible modes, and in varying wettability and rock types, (iii) experimental verification of the hypothesis that the GAGD process is largely immune to the deteriorating effects of reservoir heterogeneity and that the presence of vertical fractures possibly aid the GAGD oil recoveries, (iv) experimental demonstration of the possibility of premature gas breakthrough does not mean end of the GAGD flood, (v) preliminary mechanistic and dynamic differences between the drainage and displacement phenomenon have been identified and a new mechanism to characterize the GAGD process fluid mechanics has also been proposed.
Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-07152005-101224 |
Date | 15 July 2005 |
Creators | Kulkarni, Madhav M. |
Contributors | John Sansalone, Julius Langlinais, Anuj Gupta, Karsten Thompson, William Blanford, Dandina N. Rao |
Publisher | LSU |
Source Sets | Louisiana State University |
Language | English |
Detected Language | English |
Type | text |
Format | application/pdf |
Source | http://etd.lsu.edu/docs/available/etd-07152005-101224/ |
Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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