大庆致密油储层压裂渗吸增产表面活性剂研制及性能评价  

Development and performance evaluation of surfactant for fracturing imbibition of tight reservoirs in Daqing Oilfield

作　　者：王永昌[1,2] WANG Yongchang(Oil Production Engineering&Research Institute of PetroChina Daqing Oilfield Co Ltd,Daqing 163453,China;Heilongjiang Provincial Key Laboratory of Oil and Gas Reservoir Stimulation,Daqing 163453,China)

机构地区：[1]中国石油大庆油田有限责任公司采油工程研究院,黑龙江大庆163453 [2]黑龙江省油气藏增产增注重点实验室,黑龙江大庆163453

出　　处：《大庆石油地质与开发》2023年第1期108-114,共7页Petroleum Geology & Oilfield Development in Daqing

基　　金：中国石油天然气股份有限公司重大科技专项“难采储量有效动用技术研究与试验”(2016E-0210)。

摘　　要：大庆外围致密油藏物性差、储层岩石表面弱亲水,常规压裂液用表面活性剂洗油性能差,渗吸作用不明显,与致密储层配伍性差。为提高致密油层压裂效果,延缓产量递减,提高采收率,利用Amott瓶渗吸洗油法,从渗透率、pH、矿化度和使用浓度等方面开展了岩心渗吸洗油效率影响因素评价实验,研制的一种压裂渗吸用表面活性剂XYJ-1可渗透到低渗透储层深部,改变岩石润湿性,并通过压裂后闷井一定周期,使表面活性剂渗吸到超低渗储层孔喉内,将更多原油渗吸置换出来,进而提高单井产量及采收率。通过红外光谱及核磁共振对分子结构进行了表征,结果表明特征吸收峰与产物符合。评价结果表明,该渗吸用表面活性剂能将储层岩石表面润湿性由弱亲水性改变为强亲水性,当表面活性剂质量分数为0.20%时,表面张力为24.01 mN/m,界面张力为0.061 mN/m,接触角为26.2°,渗吸洗油效率可达21.69%,比常规压裂用助排剂渗吸洗油效率提高了1.89倍,可用于超低渗透储层的增产改造,为压裂提高采收率提供有效手段。Tight oil reservoirs in the periphery of Daqing Oilfield have poor physical properties,and reservoir rock surface is weakly water-wet.Conventional surfactants have poor displacement performance,insignificant imbibition,and poor compatibility with tight reservoirs.In order to improve fracturing effect of tight oil,delay production decline and increase oil recovery,evaluation experiment is carried out on the factors affecting imbibition displacement efficiency of cores from the aspects of permeability,pH value,salinity and concentration by Amott bottle imbibition displacementc method.The developed surfactant XYJ-1 for fracturing imbibition can penetrate deep into low permeability reservoir and change wettability of rock and can make surfactant infiltrate into pore throats of ultra-low permeability reservoir by soaking for a period of time after fracturing to imbibe more oil,and finally increase production and recovery of single well.Molecular structure is characterized by IR and HNMR,and the results show that the characteristic absorption peak is consistent with the product.Evaluation results show that imbibition surfactant can change wettability of reservoir rock surface from weak water-wet to strong water-wet.With a concentration of 0.20%,the surface tension of surfactant is 24.01 mN/m and the interfacial tension is 0.061 mN/m,with contact angle of 26.2°,and oil imbibition efficiency up to 21.69%,increased by 1.89 times higher than that of conventional drainage aids.It can be used to increase production of ultra-low permeability reservoirs,and provides effective means for fracturing to increase oil recovery.

关 键 词：超低渗储层 压裂 渗吸 表面活性剂 渗吸洗油效率 评价实验 

分 类 号：TE357[石油与天然气工程—油气田开发工程]