新型嵌段硅油防水锁剂的研制与评价

Development and Evaluation of Block Silicone Oil Anti-Water Blocking Agent

针对低渗气藏钻完井过程中外来流体侵入引发的水锁损害问题,以高含氢嵌段硅油为主剂,复配有机硅表面活性剂、消泡剂等助剂,制备了一种适用于低渗气藏的高性能防水锁剂FWB。采用红外光谱对嵌段硅油的分子结构进行了表征,并通过表面张力法、接触角法、岩心自吸法、渗透率恢复率实验和钻井液配伍性等实验综合评价了防水锁剂FWB的性能。实验结果表明,1%防水锁剂FWB可将水相表面张力大幅降低至22.28 mN/m,将水相接触角由29°提高至120°,岩心自吸水量的减少幅度达69.2%,且渗透率恢复率可提高至89.3%。该防水锁剂具有良好的钻井液配伍性。研制的防水锁剂FWB可以显著降低钻完井过程中的水锁损害程度,能有效保护低渗油气储层。

To prevent the water block damage induced by any extraneous fluid's invasion during drilling and completion operations in low-permeability gas reservoirs,a high-performance anti-water blocking agent(FWB),which is composed of hydrogen-rich block silicone oil and some additives such as organosilicon surfactant and deformer,was developed for low-permeability gas reservoirs.The infrared spectroscopy was used to characterize the molecular structure of the block silicone oil,and a series of tests,which include surface tension test,contact angle test,core imbibition test,permeability recovery ratio test,and drilling fluid compatibility test,were conducted to comprehensively evaluate the performance of this anti-water blocking agent.The test results show that,at the mass concentration of 1%,it can dramatically reduce the surface tension of the aqueous phase to 22.28 mN/m,increase the contact angle of the aqueous phase from 29°to 120°,decrease the core imbibition amount by 69.2%,and improve the permeability recovery ratio to 89.3%,and that it has good compatibility with drilling fluids.This anti-water blocking agent can significantly reduce the water block damage during drilling and completion operations and provide effective protection for low-permeability oil and gas reservoirs.