高密度低损害压井液体系

KILLING FLUID SYSTEM OF HIGH DENSITY AND LOW DAMAGE

为了解决修井、射孔等作业过程中压井液的漏失、滤失问题 ,以及由此造成的水敏、水锁、固相堵塞、乳液堵塞等地层损害 ,提出并研制了一种含可溶性固相的暂堵型高密度压井液配方体系。该体系主要由XC聚合物和YDC -LN助剂以及可水溶性加重剂组成。通过配方筛选和室内模拟试验研究 ,结果表明该体系稳定性好 ,耐温超过 10 5℃ ,滤失量小 ,抑制性强 ,岩心损害率小于 2 0 %,而且具有密度可调、返排率高等特点 ;与自来水和油田污水的配伍性好 ,应用简单、方便。

A well killing fluid of high density containing soluble bridging plugging solids and of temporary plugging is used to prevent filtration or loss circulation of the work over fluid into the formation during workover or perforating operations, so as to avoid the reservoir damages arising from water and solids blocking, water sensitivity and emulsion plugging, etc. It comprises XC polymer, YDC LN additive and water soluble weighting agent. Formula selection and laboratory simulating tests show that this system has good stability, higher temperature tolerance over 105℃,lower filtration and stronger inhibition, and the core damaging ratio is below 20%. In addition, its density is easily adjustable and it can be easily displaced after servicing, and it has good compatibility with fresh water and the produced water in the Oilfield. This system is easy and convenient for field using.