超分子自交联压裂液的研制及在深层页岩气的应用

Preparation of Supramolecular Self-crosslinking Fracturing Fluid and Its Application in Deep Shale Gas Fracturing

针对深层页岩气压裂中存在施工压力高、加砂困难的问题,文章从结构减阻与自交联携砂机理研究入手,研制了超分子自交联压裂液,实现超分子结构减阻及自交联增黏携砂。该超分子压裂液体系具有较好的增黏、携砂、减阻性能,同时具有助排、抗盐等多种功能,满足在线混配要求。可采用返排液配制成压裂液从而减少油田压裂污水排放。在深层页岩气井现场应用表明,采用返排液配制的超分子自交联压裂液平均减阻率达到77.55%,加砂强度达到3.2 t/m,减阻性能及携砂性能优于普通滑溜水压裂液,在深层页岩气压裂上具有广泛的应用前景。

In view of the problems of high operation pressure and sand addition difficulty in deep shale gas fracturing,in this paper,self-crosslinking fracturing fluid was prepared based on structural drag reduction and self-crosslinked sand carrying mechanism,realizing supramolecular drag reduction and self-crosslinked sand carrying.The supramolecular fracturing fluid system has good viscosification,sand carrying and drag reduction performance,and multiple functions such as drainage assistance and salt resistance,which can meet the requirements of online mixing.Fracturing fluid can be prepared with flowback fluid to reduce the discharge of fracturing wastewater in oilfield.The field application in deep shale gas wells shows that the supramolecular self-crosslinking fracturing fluid prepared with flowback fluid has an average drag reduction rate of 77.55%and sand loading strength of 3.2 t/m,the drag reduction performance and sand carrying performance are better than ordinary slick water fracturing fluid,so it has a wide application prospect in deep shale gas fracturing.