低渗透油藏气水交替驱不同注入参数优化

Parameters optimization of water alternating gas injection in low permeability reservoir

田树宝¹ 何永宏² 冯沙沙¹ 张红玲¹ 雷刚¹

中国石油大学（北京）石油工程教育部重点实验室，北京 102249 中国石油长庆油田公司超低渗透油藏研究中心，陕西 西安 710016

MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing 102249, China Research Center of Ultra?鄄Low Permeability Reservoir, Changqing Oilfield Company, PetroChina, Xi′an 710016, China

气窜是影响低渗透油藏注气开发效果的重要因素，气水交替（WAG）注入方式可以很好地稳定驱替前缘，从而提高宏观波及效率。低渗透油藏渗流机理复杂，影响气水交替开发效果的参数多，为了得到最佳开发效果，有必要对注入方式和参数进行优化。文中利用数值模拟方法研究了CO₂注入方式和注入参数等对低渗透油藏开发效果的影响，并对长庆油田某超低渗透油藏CO₂水交替注入方式及参数进行了优化。结果表明，最佳注入方式为CO₂水同步注入，注入周期为1 a，段塞气水比为1∶1，段塞最佳注入总量为0.44 HCPV，最佳注入层位为底部4个小层。

Gas breakthrough is an important factor which affects the development effect of low permeability reservoir. The water alternating gas (WAG) can effectively stabilize displacement front to improve macroscopic sweep efficiency. There are many factors affecting the development effect of WAG due to the complex percolation mechanism of low permeability reservoir. In order to obtain the optimal development effect, this paper uses numerical simulation to optimize different injection ways and parameters, and studies the influence of CO₂ injection ways and parameters on the development effect of low permeability reservoirs. It also optimizes the water alternating CO₂ injection ways and parameters of some reservoir in Changqing Oilfield. Results show that the best plan is that CO₂ is injected with water at the same occasion, injection cycle is one year, gas water ratio of slug is 1:1, injection volume is 0.44 HCPV and the best injection locations are four small layers at the bottom.

10.6056/dkyqt201205016