油基钻井液用丙烯酸树脂类抗高温纳米封堵剂的研制  

Synthesis of an acrylic resin and its use as a high-temperature resistant nano-plugging agent for oil-based drilling fluid

作　　者：胡德高[1] 陈小龙 HU De-gao;CHEN Xiao-long(SINOPEC Jianghan Oil Field Company,Qianjiang 433124,China;Shale Gas Exploration and Development Co.,Ltd.,SINOPEC,Chongqing 408014,China)

机构地区：[1]中国石化江汉油田分公司,湖北潜江4331242 [2]中石化重庆涪陵页岩气勘探开发有限公司,重庆408014

出　　处：《应用化工》2021年第S01期32-36,42,共6页Applied Chemical Industry

基　　金：中国石化“十条龙”重大科技攻关项目(018P18052);国家科技重大专项“涪陵页岩气开发示范工程”(2016ZX05060)与“涪陵页岩气田储层压力预测及监测技术研究”项目联合资助(31400970-19-ZC0609-0001)。

摘　　要：针对微裂缝发育的高温复杂地层油基钻井液井壁失稳问题,从提高封堵性能和高温稳定性出发,以苯乙烯(ST)、甲基苯烯酸甲酯(MMA)、丙烯酸丁酯(BA)和丙烯酸(AA)为原料,采用种子乳液聚合法,研制了一种油基钻井液抗高温纳米封堵剂。利用红外光谱仪分析了其分子结构,热重实验分析了其热稳定性,利用激光粒度仪和扫描电镜分析了其微观结构,研究了不同加量条件下对油基钻井液流变、滤失和高温高压滤失量的影响,利用中压砂床封堵实验和高温高压砂盘封堵实验研究了纳米封堵剂对不同粒度范围的砂床和平均孔径为5μm的陶瓷砂盘的封堵效果,并通过扫描电镜观察了封堵前后陶瓷砂盘的微观结构变化。结果表明封堵剂分布均匀,粒径分布较为集中,平均粒径为92 nm,热稳定性良好。加入纳米封堵剂后,油基钻井液体系流变性稳定,电稳定性有一定提高,API和高温高压滤失量明显降低。中压砂床实验和高温高压砂盘封堵实验证实合成的纳米封堵剂具有优良的封堵效果,封堵后由于吸附了较多纳米封堵剂,陶瓷砂盘表面致密性变强。同时,该纳米封堵剂具有优异的抗高温能力,200℃老化后,加入纳米封堵剂的钻井液仍具有较低的高温高压滤失量和砂盘滤失量。Aiming at solving the wellbore instability of oil-based drilling fluid(OBM)in high-temperature and complex formations with micro-fractures and improving the plugging performance and thermal stability of plugging agent,an high temperature resistant nano plugging agent for OBM use was developed using styrene(ST),methyl methacrylate(MMA),butyl acrylate(BA)and acrylic acid(AA)as raw materials with seed emulsion polymerization method.The molecular structure was analyzed by infrared spectrometer,the thermal stability was analyzed by thermogravimetric experiment,the microstructure was analyzed by both laser particle size analyzer and scanning electron microscope(SEM).The effects of the nano-plugging agents on the rheology,API and high temperature and high pressure(HTHP)fluid loss of OBMs under different dosage were studied.The medium pressure sand bed plugging experiment and the HTHP permeability plugging test(PPT)were used to study the plugging effect of nano-plugging agent on sand beds with different particle sizes and ceramic sand discs with an average pore diameter of 5μm,respectively.The microstructure changes of the ceramic sand discs before and after plugging were observed by SEM.The results showed that the plugging agent is uniformly distributed,the particle size distribution is relatively concentrated,the average particle size is 92 nm,and the thermal stability is good.After adding the nano-plugging agent,the OBMs has stable rheology,improved electrical stability,and significantly decreased API and HTHP fluid loss.The medium pressure sand bed plugging experiment and the HTHP PPT confirmed that the synthesized nano-plugging agent has an excellent plugging effect.After plugging,the surface of the ceramic sand disc becomes denser due to the adsorption of nano-plugging agents.At the same time,the nano-plugging agent has excellent high temperature resistance.After aging at 200℃,the drilling fluid added with the nano plugging agent still has low HTHP fluid losses in both sand bed plugging experiment and the HTHP P

关 键 词：油基钻井液 抗高温 纳米封堵剂 丙烯酸树脂 

分 类 号：TE254[石油与天然气工程—油气井工程]