低渗透气藏有机硅防水锁剂的制备与性能评价

Preparation and Evaluation of an Organosilicon Water Block Inhibitor for Low Permeability Gas Reservoirs

针对低渗透气藏钻完井过程中因水相侵入引发的水锁损害问题,以双端含氢硅油(DHSO)、烯丙基缩水甘油醚(AGE)、三甲胺盐酸盐(TMHC)等为原料,通过硅氢加成反应和环氧基开环反应合成了一种阳离子有机硅表面活性剂DAT,并复配消泡剂等助剂,构建了有机硅防水锁剂DAH。使用傅里叶红外光谱和核磁共振氢谱对合成产物进行表征,其分子结构符合预期设计;通过表面张力测定、岩心接触角实验、岩心自吸实验、岩心驱替实验等对防水锁剂DAH的性能进行评价。结果表明:1%DAH溶液的表面张力大幅下降至21.28 mN/m;经1%DAH溶液处理后,水相接触角由20°提高至110°,岩心自吸水量下降83.1%,渗透恢复率提高至82.68%。该防水锁剂DAH可大幅降低水相表面张力,能够通过静电作用在岩心表面形成致密吸附膜,将岩心表面润湿性由亲水性反转为疏水性,减少了钻完井过程中的水相侵入,并有助于水相返排,具有优异的降低水锁损害功效,对保护低渗储层产能具有重要意义。

To solve the waterblocking damage caused by water phase invasion during drilling and completion of the low permeability gas reservoir,a cationic silicone surfactant DAT was synthesized by the hydrosilylation and epoxy ring opening reactidouble-endedle ended hydrogenated silicone oil(DHSO),allyl glycidyl ether(AGE),trimethylamine hydrochloride(TMHC),defoamer,and other additives were used to prepare the anti-waterblocking agent DAH.Fourier transform infrared spectroscopy(FTIR)and nuclear magnetic resonance o solve the problem of water block resulted from water invasion in drilling and completion of a low permeability gas reservoir,a cationic organosilicon surfactant DAT was synthesized through hydrosilylation reaction and epoxides ring-opening reaction,and by compounding the DAT with a defoamer,an organosilicon anti-water-block agent DAH was produced.The cationic organosilicon surfactant DAT is synthesized with raw materials such as double-ended hydrogen-containing silicone oil(DHSO),allyl glycidyl ether(AGE)and trimethylamine hydrochloride(TMHC).Characterization of the final product with Fourier infrared spectroscopy and HNMR has proved that the molecular structure of the final product conforms to the expected design.The performance of DAH was evaluated by laboratory tests such as surface tension measurement,contact angle test of cores,self-imbibition test of cores,core displacement test etc.The test results reveal that a 1%DAH solution has a surface tension greatly reduced to 21.28mN/m,the contact angle of the DAH water solution is increased from 20°to 110°,the amount of water imbibed by the core sample tested is reduced by 83.1%,and the percent permeability recovery is increased to 82.68%.These test results have proved that DAH can greatly reduce the surface tension of water,and can form a tight absorptive membrane on the surfaces of a core through electrostatic action,thereby reversing the surface of the core from hydrophilic to hydrophobic,and effectively reducing the invasion of water into the formation during drilling and completion operations.This performance of DAH is also helpful to water flow back,making it an excellent additive for reducing the damage caused by water blocking;this is of great importance to the protection of the productivity of a low permeability reservoir.