孤岛油田聚合物后续水驱井下注水工艺

针对聚合物后续水驱井下注水工艺存在层窜、吐聚、吐砂严重以及地层压力测试成功率较低、分层注水方案难以实施、大部分主力油层不吸水、作业频繁、后续水驱效果不理想等问题，设计了后续水驱配套工艺，制定了新的作业施工方案，优化了分层测调方法。该技术在孤岛油田B19断块、东区注水示范区进行了试验和推广应用。结果表明，地层压力场重新分布，改善了吸水剖面，地层平均吸水率为105．5％，测试平均成功率达到92．2％，有效防止了关井后地层返吐造成的出砂现象，提高注水层段的合格率，平均达到70．15％，防止了因停注或压降造成的吐聚现象。

Downhole Injection Process About Sequel Water Flood of Polymer in Gudao Oilfield

Seeing the problems of the downhole injection process about sequel water flood of the polymer, such as communication between zones, serious reversing of polymer and sands, lower testing returns-ratio of formation pressure, difficulty in the plan of separate flooding, main layers without hygroscope, frequent operation, sequel water flood without an ideal effect, etc. a new matching process about the sequel water flood of the polymer was devised ; a new construction plan was made ; and the methods of measurement and transference about the waterflood was optimized. The technolo- gy had ever been tested, popularized and applied at block B19, oriental region of the flooding dem- onstration block in Gudao Oilfield. The result indicated that pressure field of the formation was made a redistribution, injection profile was improved, and intake capacity （the average absorption rate is up to 105.5% ） and testing returns-ratio（ the average is 92.2% ） had an effective enhancement after they were adopted. What＇ s more, the new flooding process and the new construction plan could ef- fectively guard against the sand entry after well off, raise the acceptability of the flood layers（ the average is 70.15% ） , and guard effectively against reversing out polymer as a result of a pause of the injection or drop in pressure.