杏树岗油田厚油层顶部剩余油水平井强碱三元复合驱试验效果

EXPERIMENTAL EFFECTS OF THE HONIZONTAL-WELL STRONG ALKALINE ASP FLOODING FOR THE REMAINED OIL ON THE TOP OF THICK RESERVOIRS OF XINGSHUGANG OILFIELD

杏树岗油田经过50多年开发已进入特高含水期,三次采油取得了较好开发效果。但由于受油层非均质性影响,厚油层顶部开发效率低,剩余油富集,层内矛盾突出,常规方法挖潜难度较大。为改善层内动用状况,探索挖潜厚油层顶部剩余油方法,开展了水平井强碱三元复合驱现场试验。通过优化水平轨迹、水平段长度、入靶点方向、射孔方式及完井方式设计,应用室内评价结合其他区块三元体系配方,优化注入参数设计,提高方案匹配率,试验取得较好效果,有效缓解了层内矛盾,提高了油层动用程度,采收率提高30%以上。该研究明确了水平井强碱三元复合驱动态变化规律,客观评价了水平井强碱三元复合驱的可行性,为厚油层顶部剩余油挖潜提供了新思路,为三次采油开发调整开辟了新途径。

After 50 years＇ development,Xingshugang Oilfield has entered into extra high watercut period,the tertiary oil recovery has achieved much better production effects. But due to the influence of heterogeneity of the oil reservoir,the developed efficiency of the reservoir top is rather lower,and moreover the remained oil amount there is rather larger,the in-layer contradiction is rather obvious,the potential tapping difficulty is rather bigger for the conventional methods. In order to improve the developed conditions within the reservoirs,the potential tapping method was explored for the remained oil on the top of the thick oil layers,and furthermore the horizontal-well strong alkaline ASP flooding field test was conducted. By means of the optimized horizontal trajectory,length of the horizontal interval,target entry direction,perforation and completion manners,integrated with the indoor evaluations and the other block＇s ASP formula,the injecting parameter design was optimized and the matched ratio of the programs wasincreased,thus the test effects were much better,the contradiction was effectively released,the developed degree was enhanced,the recovery was enhanced more than 30%. The study has clarified the changed laws of the ASP performances and objectively evaluated the feasibility of the flooding,therefore the new thinking is presented for tapping the potential of the remained oil on the top of the oil reservoirs and furthermore the new approach is ploughed for the development adjustment of the tertiary oil recovery.