DOI QR코드

DOI QR Code

An Analysis on Applicability of Geophysical Exploration Methods to Monitoring Polymer-flooding

물리탐사 기법들의 화학공법 모니터링 적용성 분석

  • Cheon, Seiwook (Department of Energy and Mineral Resources Engineering, Sejong University) ;
  • Park, Chanho (Department of Energy and Mineral Resources Engineering, Sejong University) ;
  • Ku, Bonjin (Department of Energy and Mineral Resources Engineering, Sejong University) ;
  • Nam, Myung Jin (Department of Energy and Mineral Resources Engineering, Sejong University) ;
  • Son, Jeong-Sul (Korea Institute of Geoscience and Mineral Resources)
  • 천세욱 (세종대학교 에너지자원공학과) ;
  • 박찬호 (세종대학교 에너지자원공학과) ;
  • 구본진 (세종대학교 에너지자원공학과) ;
  • 남명진 (세종대학교 에너지자원공학과) ;
  • 손정술 (한국지질자원연구원)
  • Received : 2015.08.10
  • Accepted : 2015.08.26
  • Published : 2015.08.31

Abstract

Polymer flooding for enhancing hydrocarbon production injects into a reservoir polymer solution that is viscous. It is very important to monitor the behavior pattern of the polymer solution in order to evaluate the effectiveness of polymer flooding. To monitor the distribution of polymer solution and thus fluid substitution within the reservoir, we first construct seismic and resistivity rock physics models (RPMs), which are functions of reservoir parameters such as rocks and type of fluid, fluid saturation. For the seismic and resistivity RPMs, responses of seismic and electromagnetic (EM) tomography are numerically simulated as polymer injection, using two dimensional (2D) staggered-grid finite difference elastic modeling and 2.5D finite element EM modeling algorithms, respectively. In constructing RPM for EM tomography, three different reservoir rocks are considered: clean-sand, dispersed shale-sand, and sand-shale lamination rocks. The polymer solution is assumed to have 2 wt% of polymer as normally generated, while water is freshwater or saltwater. Further, neutron logging is also considered to check its sensitivity to polymer flooding. The techniques discussed in the paper are important in monitoring not only hydrocarbon but also geothermal reservoirs.

탄화수소 생산에서 화학공법은 폴리머 용액을 저류층에 주입함으로써 탄화수소의 생산량을 증대시키는 방법이다. 화학공법의 유용성을 파악하기 위해서는 저류층 내 폴리머 용액의 거동 양상을 모니터링하는 것이 매우 중요하다. 저류층 내 폴리머 용액과 유체 변화에 대한 모니터링의 가능성을 확인하기 위해, 저류층을 구성하고 있는 암석 및 유체의 종류, 포화도 등의 매개변수에 따른 탄성파 및 전기비저항 암석물리모델을 구성하고, 폴리머 주입에 따른 탄성파 및 EM 토모그래피의 반응을 계산하였다. 특히 전기비저항 암석물리모델 구성에서는 순수사암, 셰일질 사암, 사암셰일박리층 3가지의 서로 다른 저류층 암석을 고려하였다. 폴리머 용액의 농도는 가장 일반적으로 이용되는 2 wt%로 하고 담수를 이용한 경우와 염수를 이용한 경우로 나누어 분석하였다. 더 나아가, 화학공법에 대한 중성자검층 민감도 분석을 수행하였다. 이 논문에서 다루는 기법들은 탄화수소 저류층뿐만 아니라 지열 저류층 등의 모니터링에 있어서도 중요하게 적용될 것이다.

Keywords

References

  1. Archie, G. E., 1942, The Electrical Resistivity Log as and Aid in Determining some Reservoir Characteristics, Trans. AIME, 146, pp. 54-62. https://doi.org/10.2118/942054-G
  2. Carlos, C., Fredy, A., Wilson, F., and Vladimir A., 2008, Timelapse seismic modeling assisted by numerical reservoir simulation of water and gas flooding scenarios in oil reservoirs, Sociedade Brasileira de Geofisica, 26(2), 195-209. https://doi.org/10.1590/S0102-261X2008000200007
  3. Dvorkin, J., and Nur, A., 2000, Critical Porosity Models, Department of Geophysics, Stanford University, Stanford, CA 94305-2215.
  4. Gassmann, F., 1951, Uber die elastizitat poroser medien, Veirteljahrsschrift der Naturforschenden Gesellschaft in Zurich, No. 96, pp. 1-23.
  5. Jang, J. H., and Nam, M. J., 2013, A Review on Nuclear Magnetic Resonance Logging: Simulation Schemes, Jigu- Mulli-wa-Mulli-Tamsa, 16(2), 97-105.
  6. Klein, J. D., Martin, P. R., and Allen, D. F., 1997, The petrophysics of electrically anisotropic reservoirs, The Log Analyst, May-June.
  7. Ku, B. J., and Nam, M. J., 2012, A study on slim-hole neutron logging based on numerical simulation, Jigu-Mulli-wa-Mulli-Tamsa., 15(4), 219-226.
  8. Ku, B. J., Nam, M. J., and Hwang, S. H., 2012, A study on slim-hole density logging based on numerical simulation, Jigu-Mulli-wa-Mulli-Tamsa., 15(4), 227-234.
  9. Lee, K. S., 2010, Comparison of Reservoir Performances for Chemical Enhanced Oil Recovery, J. Korean Soc. Miner. Energy Resour. Eng., 47(3), 291-299.
  10. Mavko, G., Mukerji, T., and Dvorkin, J., 2009, The Rock Physics Handbook: Tools for Seismic Analysis of Porous Media, 2rd ED., Cambridge University Press, USA, pp. 1-503.
  11. Nur, A., Mavko, G., Dvorkin, J., and Gal, D., 1998, Critical porosity: A Key to Relating Physical Properties to Porosity in Rocks, The Leading Edge, 17, pp. 357-362. https://doi.org/10.1190/1.1437977
  12. Phung K. T. Nguyen, Myung Jin Nam, and Seungpil Jung, 2014, A preliminary study on sensitivity of seismic responses to changes in reservoir parameters using various RPMconstructing strategies, Geosystem Engineering, 17, Issue. 4, 207-218 https://doi.org/10.1080/12269328.2014.951775
  13. Park, C. H., and Nam, M. J., 2014, A Review on Constructing Seismic Rock Physics Models Based on Gassmann's Equation for Reservoir Fluid Substition, J. Korean Soc. Miner. Energy Resour. Eng., 51(3), 448-467. https://doi.org/10.12972/ksmer.2014.51.3.448
  14. Park, C. H., Cheon, S. W., Ku, B. J., and Nam, M. J., 2014, A Review and Analysis on Constructing Electrical Resistivity Models for Hydrocarbon Reservoirs Based on the Characteristics of Shale Distribution, J. Korean Soc. Miner. Energy Resour. Eng., 51(1), 97-115. https://doi.org/10.12972/ksmer.2014.51.1.97
  15. Russell, B. H., and Smith, T., 2007, The relationship between dry rock bulk modulus and porosity − An empirical study, CREWES Research Report, 4(4), 143-147.
  16. Sharma, M., Taware, S., and Datta-Gupta, A., 2011, Optimizing Polymerflood via Rate Control, paper SPE 144833 presented at the SPE Enhanced Oil Recovery Conference, Kuala Lumpur, Malaysia, July 19-21.
  17. Simandoux, P., 1963, Dielectric Measurements on Porous Media: Application to Measurement of Water Saturation: Study of the Behavior of Argillacious Formation, SPWLA, Houston, pp. 97-124.
  18. Wang, Y., Pang, Y., Shao, Z., Han, P., Li, R., Cao, R., and He, X., 2013, The Polymer Flooding Technique Applied at High Water Cut Stage in Daqing Oilfield, paper SPE 164595 presented at the North Africa Technical Conference & Exhibition, Cairo, Egypt, April 15-17.