煤层气用低摩阻清洁酸性能研究

Study on the performance of low friction clean acid in coalbed methane

针对当前煤层气开采过程中,储层渗透率低,易受外来工作液体伤害的问题.用自制的一种两性离子表面活性剂(SHS-1)作为主剂得到了一种清洁酸.通过实验评价,SHS-1具有明显的降阻性能,有利于施工中提高液体的排量;同时,60℃时,该清洁酸降阻率与20℃时差别不大;通过圆盘实验对比HCl和清洁酸与碳酸盐岩的反应速率,表明清洁酸具有明显的降低酸岩反应速率的能力;通过酸岩反应动力学方程可以看出,清洁酸的反应级数小于HCl;对清洁酸进行破胶,破胶液的各项性能指标均能满足现场返排的要求,通过岩心伤害实验,表明该破胶液对煤芯的伤害较低.

Aiming at to solve the problem of low permeability of the reservoir and the susceptibility to damage from external working fluids during the current coalbed methane mining process.A clean acid was obtained using zwitterionic surfactant(SHS-1)as the main agent.Through experimental evaluation,SHS-1 had obvious drag reduction performance,which was conducive to the injection of large displacement liquids during application.At the same time,the drag reduction rate of the clean acid at 60°C was not much different from that at 20°C.Through rotating rock disk instrument experiment,it was shown that clean acid has the ability to significantly reduce the reaction rate of acid-rock.It could be seen from the acid-rock reaction kinetics equation that the reaction order of clean acid was less than that of HCl and the clean acid could reduce the reaction rate of acid-rock.After the breaking of clean acid,the indicators of breaking liquid could meet the requirements of flowback in application.Through the core damage experiment,it was shown that the breaking fluid had lower damage to the coal core.