›› 2019, Vol. 40 ›› Issue (1): 1-1.doi: 10.7657/XJPG20190115

   

Gas Injection EOR at Mid-Late Development Stage in Condensate Gas Reservoirs

CHEN Lei, LUO Ji, RAO Huawen, FENG Xinluo, KANG Aihong, LE Xiao   

  1. (Research Institute of Exploration and Development, Tarim Oilfield Company, PetroChina, Korla, Xinjiang 841000, China)
  • Online:2019-02-01 Published:1905-07-15

Abstract: Currently the formation pressure in Kekeya condensate gas field has dramatically declined, which is close to or lower than the maximum retrograde condensation pressure, resulting in many wells idle or unable to produce due to the increases of precipitated condensate oil around wellbores and flowing resistance. For this kind of condensate gas reservoir, it is urgent to study whether the gas injection can effectively improve the recovery rate and the development effect. Based on the investigation, indoor dry gas injection into condensate oil extraction experiment, long core displacement experiment and combined with the field injection test results, the paper evaluates and analyzes the feasibility of gas injection EOR at the mid-late development stage in the condensate gas reservoirs. The results show that with the increase of the injected gas volume, the condensate oil extraction effect is significantly enhanced and the fluidity of the condensate oil is obviously improved; gas injection is carried out when the formation pressure is higher than the maximum retrograde condensation pressure and the recovery rate of condensate oil can be improved by 10%~25%; but when the formation pressure is lower than the maximum retrograde condensation pressure, the improvement of the recovery rate of gas injection is very limited. Partial sand bodies with small scales in Kekeya condensate gas field have good sealing capabilities, in which the formation pressure is close to the maximum retrograde condensation pressure. Injection-production parameter optimization, injection-production ratio control and gradual pressurization according to the actual field situation can effectively avoid gas channeling and improve the development effect of the gas reservoirs

CLC Number: