The Development of Evaluation Chart for the Applicability of CO2 Flooding in Oil Reservoirs and Its Applications

생산유전의 CO2 공법 적용성 평가를 위한 평가차트 개발 및 응용

  • Kwon, Sunil (Korea National Oil Corporation) ;
  • Cho, Hyunjin (Department of Geoenvironmental System Eng., Hanyang University) ;
  • Ha, Sehun (Department of Geoenvironmental System Eng., Hanyang University) ;
  • Lee, Wonkyu (Korea National Oil Corporation) ;
  • Yang, Sungoh (Korea National Oil Corporation) ;
  • Sung, Wonmo (Department of Geoenvironmental System Eng., Hanyang University)
  • 권순일 (한국석유공사) ;
  • 조현진 (한양대학교 공과대학 지구환경시스템공학과) ;
  • 하세훈 (한양대학교 공과대학 지구환경시스템공학과) ;
  • 이원규 (한국석유공사) ;
  • 양성오 (한국석유공사) ;
  • 성원모 (한양대학교 공과대학 지구환경시스템공학과)
  • Received : 2007.04.12
  • Accepted : 2007.07.16
  • Published : 2007.12.31

Abstract

In this study, we present the evaluation chart for assessing the applicability of $CO_2$ flooding method to oil reservoirs. The evaluation chart consists of four categories as source availability, miscibility, applicability and injecting method of miscible flooding. The applicability of reservoir and oil in the chart has basic items of the properties such as oil gravity, viscosity, oil saturation, reservoir temperature and permeability, and these are quantitatively graded. Meanwhile, for additional items of $CO_2$ purity, reservoir thickness and formation dip, they are graded as "highmediumlow". In the case of evaluating the injection method of either continuous injection or WAG ($CO_2$), the qualitative decision will be made according to formation dip, vertical permeability, reservoir thickness, etc. The recommended score in the chart was assigned by utilizing 51 oil producing fields which $CO_2$ flooding is successfully being applied. The evaluation chart developed in this work has been applied to the Captain oil producing field located in Scotland as well as to the Onado oil field of Venezuela, which Korean oil companies have participated in. For the Captain field, the reservoir quality in terms of permeability and porosity is considered to be very excellent to flow the oil. The oil in captain field contains heavier component of $C_{21+}$ as 54%. Therefore, this heavy oil could be immiscibly displaced, hence the evaluating result with the basis of immiscible criteria shows that $CO_2$ immiscible flooding in this field could be properly applied. In the case of Onado oil producing field, since the estimated minimum miscibility pressure is lower than the reservoir pressure, it was assessed that the Onado field would be efficiently conducted for $CO_2$ miscible flooding.

본 연구에서는 회수증진기법 중 하나인 $CO_2$ 공법을 생산유전에 적용할 경우, 적용성 여부를 간단하고 정량적으로 평가할 수 있도록 하기 위한 평가차트를 개발하였다. 이 평가차트는 소스의 이용성, $CO_2$-오일의 혼합도, 저류층 및 오일 특성의 적정성, 주입기법의 평가항목으로 구성되어 있다. 저류층 및 오일의 특성에서 오일 비중, 오일 점성도, 오일 포화도, 저류층 온도 및 투과도의 기본평가항목에 대해서는 점수로 평가되며, $CO_2$ 순도, 저류층 두께 및 경사도 등의 추가평가항목에 대해서는 상 중 하로 구분하여 정량적으로 평가된다. 또한 미서블공법의 주입기법 평가에서는 지층경사, 수직투과성 및 저류층 두께 등에 따라 연속주입공법과 WAG($CO_2$) 공법의 여부가 정성적으로 평가된다. 이와 같이 구성된 평가차트에 대해 $CO_2$ 공법이 성공적으로 수행된 51개 유전의 적용사례를 분석하여 이를 토대로 $CO_2$ 공법이 가능한 추천점수를 설정하였다. 본 연구에서 개발한 평가차트를 국내 기업이 참여중인 스코틀랜드의 캡틴 생산유전과 베네수엘라의 오나도 생산유전에 적용하여 $CO_2$ 공법의 적용 가능성 여부를 평가하였다. 여기서 캡틴 유전은 저류층의 공극률과 투과도가 매우 양호하나, $C_{21+}$ 이상의 무거운 탄화수소 함유량이 54%를 넘는 중질유이다. 따라서 이러한 중질오일은 $CO_2$와 비미서블공법으로 진행되므로 비미서블공법 기준하의 기본평가항목에 대해서만 평가한 결과 비미서블 $CO_2$ 공법이 적정한 것으로 평가되었다. 한편, 베네수엘라의 오나도 유전에 대해서는 최소 미서블압력이 저류층 압력보다 낮게 산출되어 미서블 $CO_2$ 공법이 적용 가능할 것으로 평가되었다.

Keywords

Acknowledgement

Grant : 이산화탄소 활용 및 처분기술 연구

Supported by : 한국석유공사

References

  1. Zick, A. A., 'A Combined Condensing/Vaporizing Mechanism in the Displacement of Oil by Enriched Gases,' paper SPE 15493 presented at the SPE Annual Technical Conference and Exhibition, New Orleans, LA, 5-8 October(1986)
  2. Moritis, G., 'EOR Increases 24% Worldwide; Claims 10% U.S. Production,' Oil and Gas Journal, 90(16), 51-79(1992)
  3. Taber, J. J. and Martin. F. D., 'Technical Screening Guides for the Enhanced Recovery of Oil,' paper SPE 12069 presented at the 58th Annual Technical Conference and Exhibition held in San Francisco, CA, 5-8 October(1983)
  4. Sebastian, H. M., Wenger, R. S. and Renner, T. A., 'Correlation of Minimum Miscibility Pressure for Impure $CO_{2}$ Streams', paper SPE 12648 presented at the SPE Enhanced Oil Recovery Symposium held in Tulsa, OK, 15-18 April(1984)
  5. Harpole, K. J. and Hallenbeck, L. D., 'East Vacuum Grayburg San Andres Unit $CO_{2}$ Ten Year Performance Review: Evolution of a Reservoir Management Strategy and Results of WAG Optimization,' paper SPE 36710 presented at the Annual Technical Conference and Exhibition, Denver, 6-9 October(1996)
  6. Heller, J. P. and Taber, J. J., 'Influence of Reservoir Depth on Enhanced Oil Recovery by $CO_{2}$ Flooding,' paper SPE 15001 presented at the 1986 Permian Basin Oil & Gas Recovery Conference of the SPE held in Midland, TX, 13-14 March(1986)
  7. Carcoana, A. N., 'Enhanced Oil Recovery in Rumania,' paper SPE 10699 presented at the SPE Enhanced Oil Recovery Symposium held in Tulsa, OK, 4-7 April(1982)
  8. Klins, M. A. and Farouq Ali, S. M., 'Oil Production in Shallow Reservoirs By Carbon Dioxide Injection,' paper SPE 10374 presented at the SPE Eastern Regional Meeting Columbus, OH, 4-6 November(1981)
  9. Kim, S. W., Noh, H. K. and Kim H. S., 'Calculation of Vapor-Liquid Equilibria of Multicomponent Mixtures Using Continuous Thermodynamics', Korean Chem. Eng. Res., 29(6), 654-662(1991)
  10. Kwon, O. K. and Sung, W. M., 'Development and Application of Hybrid Phase Behavior Package for Phase Equilibria Computation of Reservoir Fluids Including the Components of $CO_{2},\;N_{2}$ and $C_{7+}$,' J. Kor. Ins. Mineral & Energy Res. Eng., 31(6), 111-118(1994)
  11. Stalkup, F. I., 'Status of Miscible Displacement,' paper SPE 9992 Presented at the SPE International Petroleum Exhibition and Technical Symposium held in Beijing, China, 18-26 March(1982)
  12. Klins, M. A., Carbon Dioxide Flooding - Basic Mechanisms and Project Design, International Human Resources Development Corporation, Boston(1984)
  13. Jarrell, P. M., Fox, C. E., Stein, M. H. and Webb, S. L., Practical Aspects of $CO_{2}$ Flooding., SPE Monograph Series, Texas(2002)
  14. Geffen, T. M., 'Improved Oil Recovery Could Help Ease Energy Shortage,' World Oil, 177(5), 84-88(1973)
  15. Lewin and Associates, Inc., 'The Potential and Economics of Enhanced Oil Recovery,' prepared under U.S. FEA Contract No. CO-03-50222-000, Washington, D.C., April(1976)
  16. National Petroleum Council., Enhanced Oil Recovery, NPC, Washington, D.C., Dec(1976)
  17. McRee, B. C., '$CO_{2}$: How It Works, Where It Works,' Pet. Eng., 52-63, Nov(1977)
  18. Iyoho, A. W., 'Selecting Enhanced Oil Recovery Process', World Oil, 187(6), 61-64(1978)
  19. Office of Technological Assessment., EOR Potential in the United States, McGraw-Hill, New York, NY(1978)