Petroleum Reservoir Evaluation and Development ›› 2021, Vol. 11 ›› Issue (6): 837-844.doi: 10.13809/j.cnki.cn32-1825/te.2021.06.006

• Methodological and Theory • Previous Articles     Next Articles

Effects of supercritical CO2 immersion on permeability of sandy conglomerate reservoir with different clay mineral content in Mahu

WANG Yingwei1(),WU Shunwei1,QIN Jianhua1,YE Yiping2,GAO Yang1,ZHANG Jing1   

  1. 1. Research Institute of Exploration and Development, PetroChina Xinjiang Oilfield Company, Karamay, Xinjiang 834000, China
    2. Reservoir Evaluation Division, PetroChina Xinjiang Oilfield Company, Karamay, Xinjiang 834000, China
  • Received:2020-10-09 Online:2021-12-26 Published:2021-12-31

Abstract:

In order to clarify the influence of supercritical CO2 immersion on the physical properties of glutenite reservoirs with different clay mineral content in Mahu under the conditions of Xinjiang Mahu glutenite reservoir. Several researches have been done. Firstly, the type and proportion of clay minerals in the reservoir were determined according to the results of X-ray diffraction (XRD):kaolinite (1.52 %), montmorillonite (0.42 %), chlorite (0.73 %), illite (0.68 %). Secondly, the core which is close to the pore permeability of reservoir core is made manually. Finally, under the condition of reservoir temperature at 70 ℃ and pressure of 20 MPa, using supercritical CO2 high-temperature and high-pressure reaction device, and the experimental study on the influence of supercritical CO2 immersion on the permeability of sandy conglomerate reservoir with different clay mineral content was carried out. The results show that when the clay mineral content is 2.5 % ~ 6.0 %, the permeability of the reservoir increases after the injection CO2, the lower the clay mineral content, the shorter the action time and the more obvious the permeability increase. When the clay mineral content in the reservoir is greater than 7.5 %, with the increase of the action time, the permeability gradually decreases, and the higher the clay mineral content is, the greater the decrease is. When the clay mineral content is 6.0 % ~ 7.0 %, CO2 has the best effect on improving reservoir permeability.

Key words: supercritical CO2, immersion, clay mineral content, interaction, permeability, sandy conglomerate reservoir

CLC Number: 

  • TE357