胜利油田超稠油蒸汽驱汽窜控制技术_曹嫣镔

石油勘探与开发

2012年12月PETROLEUM EXPLORATION AND DEVELOPMENT Vol.39 No.6 739 文章编号：1000-0747(2012)06-0739-05

胜利油田超稠油蒸汽驱汽窜控制技术

曹嫣镔1, 2，刘冬青2，张仲平2，王善堂2，王全1，夏道宏1

（1. 中国石油大学（华东）；2. 中国石化胜利油田分公司采油工艺研究院）

基金项目：国家重大科技专项“大型油气田及煤层气开发”（2011ZX05011-002）

摘要：针对超稠油油藏蒸汽驱过程中汽窜严重的问题，开展室内蒸汽驱汽窜控制技术研究，将氮气泡沫与热固性堵剂相结合封堵汽窜，热固性堵剂封堵大孔道，氮气泡沫调整蒸汽的吸汽剖面。优化后的泡沫剂体系300 ℃阻力因子达到30以上，且对低含油饱和度区域具有选择性封堵作用，适用于超稠油油藏条件下高渗透带的封堵；热固性堵剂在静态120 ℃可4 h形成固结，150 ℃可2 h有效固结，在蒸汽动态驱替过程中可形成有效封堵。利用双岩心管开展堵调工艺评价研究，结果表明，采用热固性堵剂和氮气泡沫相结合的封堵汽窜方式比单纯应用氮气泡沫提高采收率5.7%，驱替效率整体达到60.8%。2011年在单56超稠油藏进行现场实施，措施后综合含水下降10.2%，生产井井口温度下降15 ℃，井组日产油量增加28 t以上，单轮次措施有效期198 d，措施增油2 562 t，效果明显。图7表2参10

关键词：超稠油；蒸汽驱；泡沫；热固性堵剂；汽窜

中图分类号：TE357.4 文献标识码：A

Steam channeling control in the steam flooding of super heavy oil reservoirs, Shengli Oilfield Cao Yanbin1, 2, Liu Dongqing2, Zhang Zhongping2, Wang Shantang2, Wang Quan1, Xia Daohong1

(1. China University of Petroleum (EastChina), Dongying 257000, China; 2. Shengli Oil Production Research

Institute, SLOF, Sinopec, Dongying 257000, China)

Abstract:In view of the severe steam channeling in the steam flooding of super heavy reservoir, lab experiment on steam channeling control were carried out. The combination of nitrogen foam and thermoset blocking agent was tested to seal steam channeling, in which thermoset blocking agent plugs big pore throats, while nitrogen foam adjusts steam absorption profile. The optimized foam formulation has a resistance factor of over 30 at 300 ℃, can plug low oil saturation areas selectively, and applies to the plugging of high permeability zones in super-heavy oil reservoirs. Thermoset blocking agent, which would consolidate at 120 in 4 h and consolidate at 150

℃ in 2 h,

℃can provide effective plugging during dynamic steam flooding. The best steam channeling control mode was determined using parallel tube model. By the combination of nitrogen foam and thermoset blocking agent, the recovery rate is 5.7% higher than the application of nitrogen foam only, with the overall sweeping efficiency reaching up to 60.8%. In 2011, the mode was used in the steam flooding in Shan-56 reservoir. The water cut drops 10.2%, the wellhead temperature of producer drops more than 15 ℃, the oil production of the well group increases over 28 tons per day, the valid period of a single cycle is up to 198 days, and the oil production increases 2 562 t, showing significant improvement in steam flooding.

Key words:super heavy oil; steam flooding; nitrogen foam; thermoset blocking agent; steam channeling

0 引言

超稠油油藏黏度高、流动性差，蒸汽与稠油流度比大，蒸汽驱过程中极易发生汽窜，导致温度场发育不均匀，生产井综合含水上升，井口温度上升，热利用率低，这也是超稠油蒸汽驱提高采收率最大的难点所在[1-4]。胜利油田超稠油油藏储量丰富，其中单56是典型的超稠油藏，埋深1 080～1 150 m，油藏条件下稠油黏度47 000～92 000 mPa・s，油层厚度30 m，孔隙度30%～36%，渗透率3～4 μm2，油水体积比为1。该区块主体2001年投入开发，经过加密，2007年井距为140 m×100 m，其中超稠油蒸汽驱试验井组含油面积0.23 km2，地质储量124×104t，注汽井4口，生产井21口，采出程度达到21.3%，综合含水79.2%，油藏压力已下降到5 MPa以下。对于单56区块，单纯采用蒸汽吞吐的开采方式剩余可采储量有限，必须通过转换开发方式进一步提高采收率。2008年9月开始在单56-9-N13等4个井组开展蒸汽驱现场试验，通过转换开发方式稳定了井组产量，采油速度在2.9%，油汽比0.29，取得良好的开发效果。试验过程中超稠油油藏蒸汽汽窜严重，试验井组2年内发生汽窜28井次，一旦发生汽窜，采用关井、降低注汽速度等措施，影