注采优化提高平面非均质低渗油藏井网水驱波及效率

Improvement of waterflooding sweeping efficiency of the well patterns in low-permeability oil reservoirs with plane heterogeneity based on injection and production optimization

郭迎春 曲全工 曹小朋 季迎春 邹建 苗明 宋黎光 冯海如 王志兴

GUO Yingchun QU Quangong CAO Xiaopeng JI Yingchun ZOU Jian MIAO Ming SONG Liguang FENG Hairu WANG Zhixing

中石化胜利油田分公司勘探开发研究院 中国石油大学(北京) 中国石油三次采油重点实验室低渗油田提高采收率应用基础理论研究室 石油工程教育部重点实验室

Exploration and Development Research Institute, SINOPEC Shengli Oilfield Company, Dongying 257093, Shandong, China China University of Petroleum (Beijing), Beijing 102249, China Applied Basic Theory Research Institute of Low Permeability Oilfield EOR, PetroChina Key Laboratory of Tertiary Oil Recovery, Beijing 102249, China Key Laboratory of Petroleum Engineering, the Ministry of Education, Beijing 102249, China

不稳定注水广泛应用于非均质油藏的水驱开发，为进一步改善平面非均质低渗油藏水驱开发效果，采用与目标油藏对应的径向流物理模型，分析了3种注采方式下平面非均质油藏井组生产井生产动态及采收率，明确了3种注采方式改善水驱开发效果的作用机理，并给出3种不同注采方式的适用性。结果表明：不稳定注水方式可形成不稳定压力场，形成油水交渗及弹性力驱油，改善低渗区域的驱油效果；同步平衡产液量注采方式可改善整体水驱波及效率，并利用不稳定注水提高低渗区域原油采收率，整体采收率较高；异步平衡产液量注采方式可在不稳定注水后，调整注采压差，提高低渗区域驱油效率，同时扩大注入水对低渗区域的波及效率，大幅度提高低渗区域的采收率。实验结果可为目标油藏水驱开发注采方式优化提供理论支持。

Unstable water injection is widely applied to the waterflooding development of heterogeneous oil reservoirs. In order to further improve the waterflooding effect of low-permeability oil reservoirs with plane heterogeneity, this paper adopted the radial-flow physical model corresponding to the target oil reservoir to analyze the production performance and recovery factor of the production wells of the well group in the plane heterogeneous oil reservoirs in three kinds of injection/production modes. Then, the mechanisms of improving the waterflooding effect in these three kinds of injection/production modes were clarified, and their applicability was pointed out. It is indicated that by means of unstable water injection, unstable pressure field can be formed and oil-water mutual flow and elastic drive are realized, so that the oil displacement effect in the low-permeability areas is improved. The injection/production method with synchronously balanced liquid production rate can improve the overall waterflooding sweeping efficiency and make use of the unstable water injection to increase the recovery factor of low-permeability areas, so as to improve the overall recovery factor. The injection/production method with asynchronously balanced liquid production rate can increase the oil displacement efficiency of low-permeability areas by adjusting the injection/production pressure difference after the unstable water injection. In the meantime, it increases the sweeping efficiency of the injected water in low-permeability areas, so as to improve the recovery factor of low-permeability areas greatly. The experimental results provide the theoretical support for optimizing the injection and production mode of waterflooding development of the target oil reservoir.

10.13639/j.odpt.2020.02.015