孤岛油田西区三元复合驱矿场试验

Enlarged Field Test on ASP-Flood at East District of Gudao Oil Field

孤岛油田西区三元复合驱矿场扩大试验区包括 6口注水井和 13口采油井。介绍了试验区油藏地质特征。所设计的超低界面张力三元复合驱油溶液 (主段塞 )配方为 :1.2 %Na2 CO3+0 .3%复配表面活性剂 (阴离子表面活性剂BES +木质素磺酸盐PS) +0 .15 %聚合物 35 30S。从 1997年 5月开始实施化学剂注入 ,实际注入情况如下 :前置段塞(0 .2 0 %聚合物溶液 ) 0 .0 97PV ;主段塞 0 .30 9PV ;后置段塞 (0 .15 %聚合物溶液 ) 0 .0 5PV ,2 0 0 1年 11月转后续水驱。本文介绍注完化学剂时的试验效果 ,包括 :全区油井综合含水由 94 .7%降至 84 .5 % ,日产油量由 82t升至 194t,累计增油 10 .4 2× 10 4 t,提高采收率 5 .2 7% ,预计最终提高采收率 12 .0 4 % ;注水井纵向各层吸水均匀化 ,注水井流动系数和流度下降 ;注水利用率提高 ,每采出 1t原油的耗水量由 17.9t降至 10 .4t。从受效方向、油层构造、沉积微相、窜流等 4个方面分析了各油井增油减水效果不同的原因。图 3表 3参 7。

There are 6 injection and 13 production wells in the APS flooding test area of east district of Gudao oil field, Shengli. The geologic characteristics of the reservoir in the test area are described. The ASP flooding solution (main slug) designed is composed of 1.2% Na 2CO 3, 0.3% combinational surfactants (anionic surfactant BES+lignosulfonate PS), and 0.15% polymer 3530S and possesses ultralow interfacial tension with the crude oil. The injection of the chemicals has been started in may 1997 according to a modified scheme as follows: 0.20% polymer solution as pad slug of size 0.097 PV; main ASP slug of size 0.309 PV; 0.15% polymer solution as postpad slug of size 0.05 PV; and successive flooding water started in Nov 2001. The test results at the end of chemical injection are presented: in the whole test area the combained water cut decreases from 94.7% to 84.5%, the oil production increases from 82 t to 194 t per day, the incremental oil production reaches 1.04×10 5 t accumulatively, the enhancement in oil recovery obtained accounts 5.27% and that predicted by UTCHEM at the end of the field test will be of 12.04%; the watertake of reservoir layers in injection wells becomes more even and the flow coefficient and the fluidity in injection wells are lowered; the ratio of produced oil to produced water is decreased from 17.9 to 10.4. The differences in chemical flood response of some production wells are analysed in terms of flooding directions, layer construction, sedimentary microfacies, and existance of channellings.