Research on key technology of packer rubber barrel for integrated fracturing and completion of gas well

Abstract

The staged and layered fracturing technology plays an important role in unconventional tight reservoirs. And the gas well fracturing and completion integration is the core component to realize the fracturing and completion integration process, which can realize the integration of acid fracturing and later drainage production so as to reduce the secondary pollution to the reservoir. The packer rubber barrel’s performance directly affects the long-term effective sealing reliability itself in high temperature and high pressure environment. In this paper, the constitutive model of rubber tested from high temperature and high pressure curing kettle to simulate the high-temperature and highly corrosive environment of the formation. On this basis, the structure of the packer’s shoulder and the protective ring of the rubber barrels are optimized through Abaqus to reduce its stress failure under high pressure, and its corrosion resistance is improved by improving the rubber material. The sealing performance of the packer rubber cylinder under the field underground requirements is tested through laboratory evaluation test and field test. The results show that the protective ring and rubber tube shoulder at 30° angle are a reasonable result of optimization, and the optimized packer can meet the requirements of 154 °C temperature resistance, 79 MPa pressure bearing and long-term effective sealing. The successful development of packer rubber and the integrated analysis process can lay a solid foundation for the realization of integrated fracturing and completion process for exploration and development of deep volcanic or carbonate reservoirs.

Numerical study on mechanical responses of AHR and BWD packer under a cyclic loading

“…As the only part of the packer functioning sealing, the mechanical property of the rubber cylinders with limited deformation under the setting pressure and the contact state with the well wall determines the packer's sealing property. However, failures often happen to the rubber cylinders in the down-hole environment [1][2][3] . Therefore, the focus of investigation on the packer's sealing performance should be put on the rubber cylinder's stress state and deformation.…”