为明确页岩-氧化液反应特征,采用3种氧化剂对四川龙马溪组富有机质页岩的氧化溶蚀效果进行了研究,探讨了氧化剂种类和浓度、温度、固液比等因素的影响,并开展了页岩氧化反应动力学实验研究。结果表明,NaClO能使页岩中的黄铁矿、白云石等矿物及噻吩、亚砜等有机质发生氧化形成溶蚀孔隙,页岩储层的平均孔径从4.54 nm增大至14.21 nm;随着NaClO浓度、温度、固液比的增大,页岩溶蚀率先增大后减小。通过氧化反应动力学研究发现,反应速率随NaClO浓度变化呈幂函数增长,随温度变化呈指数增长,NaClO浓度为0.6 mol/L时,反应活化能为31 255.6 J/mol。

Chemical oxidation,as one of the important methods to improve shale gas desorption,can effectively solve the problems of difficult desorption and low permeability in shale gas exploitation.In order to clarify the characteristics of shale-oxidation fluid reaction,three kinds of oxidants are employed to study their oxidation and turbidity-dissolving effects on organics-rich shale in Longmaxi Formation,Sichuan province,China.The influences of the type and concentration of oxidant,temperature,solid-liquid ratio and other factors are tested.Moreover,the kinetics of shale oxidation reaction is studied through experiments.It is shown that NaClO can oxidize minerals such as pyrite and dolomite,and organic matters such as thiophene and sulfoxide in the shale to form dissolution pores.The average pore size of the shale reservoir increases from 4.54 nm to 14.21 nm due to dissolution.With the increasing NaClO concentration,temperature and solid-liquid ratio,shale dissolution rate increases firstly and decreases then.The reaction speed increases as a power function with the change of NaClO concentration and increases exponentially with the change of temperature.The activation energy of the reaction is 31 255.6 J·mol^-1 when the concentration of NaClO is 0.6 mol·L^-1.

肖湑桥(1998-),男,硕士生,研究方向为化学氧化强化页岩气解吸技术,13693477348@163.com。