“一井一制”聚合物注入段塞的设计与应用

Design and application of polymer injecting slug by “one scheme for one well”.

原有聚合物驱的设计和实施采用“分阶段、统一段塞”的注入方式，即同一阶段内，注聚区的所有注入井注相同浓度的聚合物溶液段塞，不同阶段，聚合物溶液的浓度不同。这种方式没有区别各井区不同的地层参数，使有的井因粘度太低而仍存在聚合物窜流，而有的井则因粘度太高注不进去。根据孤东油田七区西Ｎｇ５２＋３层和八区Ｎｇ３～６层的聚合物驱工业性矿场试验中暴露出的问题，提出并实施了“一井一制”聚合物注入段塞，井与井之间、同一井的不同时段，其注入段塞也不同。为了实现这一点，根据流动系数、单井注入压力、吸水指数、启动压力、大孔道分布等５个条件，设计了５种段塞，在不同井、不同时段注入。１９９６年８月起在七区西的３７口井上实施，２６口井见效，到１９９７年７月，比原聚合物驱又增油２０１９０ｔ；在八区推广实施３个月，也取得明显增油效果。

The design and application of polymer flooding used in the past is “unitized slug in each stage”. It means that all injected well are the same polymer solution slug in the same stage and different stage with different slug. This manner didnt consider the different formation parameters in different well, consequently resulted in polymer channeling in some wells with low viscosity and blocking in some other wells with high viscosity. In view of the problem appeared in the polymer flooding field test in Gudong oilfield Qiquxi Ng5 2+3 layer and Baqu Ng3～6 layer,we put forward and carried out a polymer injected manner called “one scheme for one well”.That is different slug for different stage and different well. According to the five factors of flow coefficient, single well injected pressure, injectivity index, starting pressure and large pore distribution, we designed five kinds of slug in different stage and different well. From August 1996 to July 1997, we carried out field tests in 37 wells, 26 wells were effective,with oil 20190 ton more than original polymer flooding manner. We carried it out for 3 months in Baqu block and obtained good result too.