新疆石油地质 ›› 2026, Vol. 47 ›› Issue (2): 184-191.doi: 10.7657/XJPG20260207

• 油藏工程 • 上一篇    下一篇

伴生气驱提高采收率可行性实验及注采优化——以鄂尔多斯盆地西233区长7组页岩油为例

陈波a(), 刘帅帅b, 王义俊a, 冷先刚a, 雷启鸿c, 李德胜a, 王宁a   

  1. 中国石油 长庆油田分公司 a.陇东油气开发分公司,甘肃 庆阳 745100;b.第二采气厂,陕西 榆林 719000;c.页岩油开发分公司甘肃 庆阳 745100
  • 收稿日期:2024-12-03 修回日期:2025-01-17 出版日期:2026-04-01 发布日期:2026-04-08
  • 作者简介:陈波(1988-),男,四川资阳人,高级工程师,硕士,油气田开发,(Tel)18298880301(Email)chenb01_cq@petrochina.com.cn
  • 基金资助:
    中国石油重大科技专项(2023ZZ15YJ01);甘肃省联合科研基金重大项目(24JRRM012)

Feasibility Experiments and Injection/Production Optimization of Associated Gas Flooding for Enhanced Oil Recovery: A Case Study of the Chang 7 Shale Oil in the West 233 Area of the Ordos Basin

CHEN Boa(), LIU Shuaishuaib, WANG Yijuna, LENG Xianganga, LEI Qihongc, LI Deshenga, WANG Ninga   

  1. PetroChina Changqing Oilfield Company, a. Longdong Oil and Gas Development Company, Qingyang, Gansu 745100, China; b. No.2 Gas Production Plant, Yulin, Shaanxi 719000, China; c. Shale Oil Development Company, Qingyang, Gansu 745100, China
  • Received:2024-12-03 Revised:2025-01-17 Online:2026-04-01 Published:2026-04-08

摘要:

鄂尔多斯盆地西233区长7组发育典型夹层型页岩油,地层压力系数低,产量快速递减,伴生气丰富。对储集层岩心样品开展伴生气驱实验,结合核磁共振T2谱分析伴生气驱及吞吐实验,模拟不同井距下吞吐效率。结果表明:束缚水明显降低伴生气驱效率,驱替后横向弛豫时间大于10 ms孔隙信号强度大幅下降,驱替出来的原油主要贡献孔隙为大孔,小孔原油小幅度动用,残余油量大。伴生气吞吐能有效提高页岩油采收率,第1次吞吐原油采收贡献率最大,2个吞吐轮次后,地层原油采收率大于85%,第3次吞吐采收率小于15%,第4次吞吐采收率基本不变,表明主要动用了大孔中的原油,随吞吐轮次增加,吞吐增油量减小,换油率降低,采收率增大幅度降低,逐渐进入低效循环。200 m井距下水平井伴生气吞吐,最佳注入伴生气时间为639 d,最佳段塞体积为900 m3,最佳注气速度为15 m3/d,最佳焖井时间为40 d,最佳周期注采时间为160 d,最佳吞吐轮次为3次。连续伴生气驱最佳时机为1 200 d,最佳注气速度为15 m3/d。

关键词: 鄂尔多斯盆地, 长7组, 页岩油, 伴生气驱, 伴生气吞吐, 提高采收率, 注采优化, 数值模拟

Abstract:

The Chang 7 reservoir in the West 233 area of the Ordos Basin is a typical sandwiched shale oil accumulation with low formation pressure coefficient, rapid production decline, and abundant associated gas. Associated gas flooding experiments were conducted on reservoir rock samples. Combined with NMR T2 spectra, the results of associated gas flooding and huff-n-puff experiments were analyzed, and the huff-n-puff efficiency under varying well spacing was simulated. The results show that the presence of bound water significantly reduces the efficiency of associated gas flooding. After displacement, the signal intensity of pores with T2>10 ms decreases significantly; the displaced oil mainly comes from large pores, while only a small part of oil in small pores is mobilized, leaving a large quantity of residual oil. Associated gas huff-n-puff can effectively improve the recovery of shale oil, with the first cycle contributing most to the recovery, the second cycle witnessing a recovery greater than 85% OOIP, the third cycle recording a recovery not exceeding 15%, and the fourth cycle remaining a recovery basically unchanged. This indicates that the oil in large pores has been mainly mobilized. With the increase of huff-n-puff cycles, the incremental oil production decreases, the oil replacement rate drops, and the increase in recovery factor slows down, gradually entering an inefficient cycle. For associated gas huff-n-puff in horizontal wells with well spacing of 200 m, the optimal associated gas injection time is 639 d, the optimal slug size is 900 m3, the optimal injection rate is 15 m3/d, the optimal shut-in time is 40 d, the optimal injection-production time per cycle is 160 d, and the optimal number of huff-n-puff cycles is 3. The optimal timing for continuous associated gas flooding is 1,200 d, and the optimal associated gas injection rate is 15 m3/d.

Key words: Ordos Basin, Chang 7 formation, shale oil reservoir, associated gas flooding, associated gas huff-n-puff, enhanced oil recovery, injection-production optimization, numerical simulation

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