黏弹性转向酸转向剂的研制及性能评价

DEVELOPMENT AND PERFORMANCE EVALUATION OF VISCOELASTIC TURNING ACID DI⁃VERTING AGENT

压裂酸化储层改造中,目的是为了解除地层污染堵塞,尽可能沟通孔洞,实现在地层均匀布酸,常规酸酸岩反应速度快和滤失,酸液优先进入储层的大孔道或高渗透部分发生指进,酸液在地层达不到均匀布酸,从而降低储层改造效果的情况;在室内以丙烯酰胺、AMPS为单体和一定浓度的聚氧乙烯二丙烯酸酯,在引发剂的作用下共聚合成一种黏弹性表面活性转向剂SD,利用该转向剂配制黏弹性转向酸TAC-SD,并对其进行性能评价,评价结果表明,转向剂在酸液体系中的配伍性好,酸液浓度在20%时,黏弹性转向酸TAC-SD黏度为30mPa.s,酸液浓度在14%时,峰值黏度为255mPa.s,转向点酸浓度为17%,转向范围为17%~12%,室内岩心流动实验表明,转向酸TAC-SD转向效果明显;在川渝地区现场应用4口井,从现场施工井反馈情况分析,黏弹性转向酸在地层转向效果明显,为酸液在地层均匀布酸,提高储层改造效果提供了有力保障。

Fracture acidizing reservoir reconstruction,the purpose is to remove plugging formation pollution,communication holes,as far as possible to achieve in acid formation uniform cloth,conventional rock reaction speed and filtration,attracts many acid into reservoir macroscopic throats priority or high permeability part fingering,acid formation are not uniform,thus reducing effect of reservoir reconstruction;Indoors with acrylamide and AMPS as monomer and a certain concentration of poly⁃oxyethylene acrylate,under the action of the initiator,copolymerization to synthesize a kind of viscoelastic surfactant to SD,us⁃ing the divertor configuration viscoelasticity steering acid TAC-SD,and carries on the performance evaluation,the evalua⁃tion results show that the diverter in acid system compatibility is good;the acid concentration is 20%;the viscoelasticity steer⁃ing acid TAC-SD viscosity is 30 mpa.S;as acid concentration is 14%,the peak viscosity is 255 mpa.S,turning point acid con⁃centration is 17%,steering range of 17%~12%.Laboratory core flow experiments show that TAC-SD steering acid has obvi⁃ous effect.Four Wells were applied in Sichuan and Chongqing area,and the feedback analysis from the on-site construction Wells showed that the viscoelastic turning acid had obvious turning effect in the formation,which provided a strong guarantee for the acid uniformly distributing acid in the formation and improving the effect of reservoir reconstruction.