Development of Rubber Packing Element for 105 MPa/215 °C Deep-Well Test Packer

Abstract

The rubber packing element is one of the most important parts of deep-well test packers, but the existing rubber packing elements are insufficient to meet the requirements of field use as the stratum temperature and pressure rise as drilling becomes deeper. In this study, a rubber material formulation that meets the actual needs of the field (can withstand a high temperature and high pressure of 215 °C/105 MPa) was designed. Based on this, a mathematical model of the packer’s rubber packing elements was established, and its structure was analyzed using finite element software. Furthermore, the rubber packing elements produced according to this design were verified in an indoor simulation experiment. The results of structural analysis show that the best sealing was achieved when the end-face inclusion angle of the rubber packing element was set at around 40°, the length of the rubber packing element was between 60 and 80 mm, and the hardness was greater than or equal to 90 HA. Under the experimental conditions of 105 MPa and 215 °C, the experimental device stabilized at a pressure for 62 h and the pressure drop was 0.3 MPa, meaning that the elements passed the experiment and, thus, they can go through the setting-down process and function well in normal works. For the rubber packing elements with a sealing capacity and temperature resistance of 105 MPa and 215 °C, respectively, developed in this paper, their sealing reliability was verified through indoor simulation experiments, providing an important guarantee in terms of the smooth implementation of deep-well testing and the completion of operations at high temperature and high pressure.