新型高性能转向酸的制备及性能评价

碳酸盐岩储层微裂缝发育，酸化压裂改造过程中酸液单向突进，造成储层有效裂缝沟通困难，酸化压裂改造效率低。为了提高碳酸盐岩储层酸化压裂改造效率，制备了一种对CO₂敏感的新型高性能转向酸体系，该体系主要由盐酸、SDS、TMPDA及缓蚀剂组成，配方为3.96% SDS+1.09% TMPDA+24% HCl+0.5% MZ-1缓蚀剂。虽然该体系本身不具有黏弹性，但在CO₂存在的条件下，体系中的TMPDA作为联接基与普通的SDS生成黏弹性极好的类Gemini型表面活性剂，CO₂消除之后可恢复到初始状态。相关性能评价及研究表明，该体系抗温、抗剪切性好、转向性能优越，酸液驱替前后岩心渗透率明显增大，而且渗透率差异较大的2组岩心的渗透率极差基本消除，可以有效地提高碳酸盐岩储层酸压改造效率，而且有希望实现循环利用。 

Preparation and Evaluation of a New High Performance Diverting Acid

Carbonate rock reservoirs have plenty of micro fractures. Unidirectional fngering of acid solution in acidizing carbonate reservoirs always results in diffculties in communicating fractures and low effciency of acidizing fracturing job. To improve the job effciency, a new high performance diverting acid, which is sensitive to CO2, has been developed. The diverting acid has a formulation as follows:3.96%SDS+1.09% MPDA+24% HCl+0.5% Z-1 (a corrosion inhibitor). This acid, although not viscoelastic, can acquire viscoelasticity through the reaction of TMPDA with SDS at the presence of CO2, because the reaction of TMPDA with SDS produces a surfactant Gemini which had superior viscoelasticity. The diverting acid resumed its original state as soon as CO2 disappeared. Laboratory study has shown that this diverting acid had good high temperature stability, good shearing performance, and superior diverting ability. In core experiment, several groups of cores were displaced with the new diverting acid. It was found that the permeability of the acid-flooded cores increased remarkably, even after removing the biggest permeability increases of two groups of cores. The effciency of acidizing fracturing job can be improved with the new diverting acid, and recycling of the diverting acid may also be realized.