Xinjiang Petroleum Geology ›› 2025, Vol. 46 ›› Issue (2): 224-230.doi: 10.7657/XJPG20250212

• RESERVOIR ENGINEERING • Previous Articles     Next Articles

Causes Behind Low Recovery in Tight Sandstone Gas Reservoirs

DAI Jinyou(), LEI Xizhen, SHI Yangyang, PAN Zhiyang, SHEN Xiaoshu, ZHANG Lijuan, ZHOU Xiaofeng   

  1. School of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102249, China
  • Received:2024-10-29 Revised:2024-12-03 Online:2025-04-01 Published:2025-03-26

Abstract:

To identify the causes behind low recovery in tight sandstone gas reservoirs, taking the Shan 2 gas reservoir in the Zizhou gas field as an example, and based on the definition of recovery for gas reservoirs, a zonal reserves producing model and an analytical theoretical model for recovery were established. With the 2 models, the recovery of the gas reservoir was calculated, and the causes behind the low recovery in the tight sandstone gas reservoir were systematically analyzed. The results show that the low recovery in the Shan 2 gas reservoir is primarily attributed to the low vertical sweep coefficient, low plane sweep coefficient, and low gas displacement efficiency. The vertical sweep coefficient is mainly influenced by the vertical heterogeneity of the reservoir, the gas displacement efficiency is closely related to the abandonment pressure of the gas reservoir, while the plane sweep efficiency is primarily constrained by the horizontal heterogeneity of the reservoir and the controlling extent of well pattern. Rationalizing well pattern deployment and enhancing plane sweep coefficient are effective methods for increasing the recovery of tight sandstone gas reservoirs. However, even when the plane sweep coefficient is 100%, the ultimate recovery remains relatively low. Therefore, strengthening research on increasing vertical sweep coefficient and improving gas displacement efficiency is crucial for enhancing recovery in tight sandstone gas reservoirs.

Key words: tight sandstone gas reservoir, low recovery cause, zonal reserves producing model, recovery, analytical theoretical model

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