低渗透致密油藏压裂用微乳增产助剂  

Microemulsion Stimulation Agent for Fracturing of Low Permeability Tight Oil Reservoir

作　　者：刘倩[1,2] 问晓勇[1,2] 王文雄 刘怡 尹太恒[1,2] 马欢 丁勇 贾建鹏 LIU Qian;WEN Xiaoyong;WANG Wenxiong;LIU Yi;YIN Taiheng;MA Huan;DING Yong;JIA Jianpeng(National Engineering Laboratory for Exploration and Development of Low Permeability Oil and Gas Fields,Xi’an,Shaanxi 710018,P R of China;Oil&Gas Technology Research Institute,Changqing Oilfield Company,Xi’an,Shaanxi 710018,P R of China;Petroleum Pre-prospecting Project Department,Changqing Oilfield Company,Qingyang,Gansu 745000,P R of China;Natural Gas Exploration Project Department,Changqing Oilfield Company,Yulin,Shaanxi 718500,P R of China)

机构地区：[1]低渗透油气田勘探开发国家工程实验室,陕西西安710018 [2]长庆油田分公司油气工艺研究院,陕西西安710018 [3]长庆油田分公司石油预探项目部,甘肃庆阳745000 [4]长庆油田分公司天然气勘探项目部,陕西榆林718500

出　　处：《油田化学》2025年第1期44-51,共8页Oilfield Chemistry

基　　金：中国石油股份公司重大专项“储层改造关键技术与装备研究”(项目编号2021DJ4506)。

摘　　要：针对低渗透致密油藏的渗吸增产,基于“压-注-采”一体化施工方式,从提高压裂液性能出发,以脂肪醇烷氧基化硫酸盐阴离子表面活性剂(SY-1)和9-葵烯酸甲酯(MS-9)为主要原料,通过拟三元相图研究相行为,采用正交实验优化配方制得增产助剂微乳液ME,通过室内实验评价了其性能,测试了在压裂过程中的增产效果。结果表明,制备ME的最佳配方为:25%SY-1+12.5%三乙二醇丁醚+37.5%的2%KCl水溶液+25%MS-9。该微乳液的平均粒径为70.5 nm;能在长时间(180 d)静置和高速离心(8000 r/min)条件下保持稳定;可将油水界面张力降低至10^(-4)~10^(-3)m N/m数量级;与清水相比,可使云母片表面的接触角降低约35°;经岩心粉8次吸附后仍能维持高界面活性,抗吸附能力较强。与压裂液的配伍性良好。以未添加ME的压裂液作为空白对照,在模拟压裂入井阶段时可将洗油效率提升54.94百分点~61.82百分点,焖井阶段可将渗吸置换效果提升15.68百分点,返排阶段可加快原油采出速度和采出程度,将原油采收率增加32.56百分点。该微乳液粒径小、稳定性强、油水界面张力低、改善润湿效果良好、抗吸附能力强,可在压裂施工全过程增大原油采收率,增渗驱油作用效果显著。In order to achieve imbibition stimulation of low permeability tight oil reservoirs,a microemulsion additive(ME)for increasing production by imbibition stimulation was developed,based on the integrated construction method of“compression-injection-recapture”and with the goal of improving the performance of fracturing fluids.The major raw ingredients were fatty alcohol alkoxylation sulfate anionic surfactant(SY-1)and methyl 9-octanoate(MS-9).The phase behavior was explored by fitting a ternary phase diagram,and then the formula was optimized using orthogonal tests.Its performance was evaluated by laboratory experiment,and then the stimulation effect during fracturing was tested.The results showed that the optimum formula for preparing ME was obtained as follows:25%SY-1,12.5%triethylene glycol butyl ether,37.5%KCl aqueous solution(2%mass fraction)and 25%MS-9.The average particle size of the microemulsion was 70.5 nm.It could keep stable under the conditions of long standing(180 days)and high-speed centrifugation(8000 r/min).It could also reduce the interfacial tension to the order of 10^(-4)—10^(-3)mN/m.Compared with water,it could reduce the contact angle by approximately 35°.It could maintain high interfacial activity after 8 adsorptions with core powders,indicating strong anti-sorption ability.It had good compatibility with fracturing fluid.When the fracturing fluid without ME was used as blank control,ME could enhance the oil washing efficiency by 54.94 percentage points—61.82 percentage points during the simulated fracturing entry stage.During the simulated fracturing well stage,the imbibition displacement impact might be raised by 15.68 percentage points.Meanwhile,during the flowback stage,it could accelerate the speed and degree of crude oil recovery,and then the crude oil recovery rate could be increased by 32.56 percentage points.The microemulsion had the advantages of small particle size,strong stability,low interfacial tension between oil and water,good wetting improvement effect and strong adsor

关 键 词：压裂 微乳液 渗吸置换 界面张力 润湿性 低渗透致密油藏 

分 类 号：TE348[石油与天然气工程—油气田开发工程] TE357