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.

New methodology to predict operational limit of hydrogenated acrylonitrile butadiene rubber packer element for downhole application in energy industry

“…The new findings extended our previous works 14,15 to more complex geometry and compression of HNBR downhole packer using fundamental material behavior such as viscoelasticity, hyperelasticity, chemical degradation based on laboratory tests, and FEA for long-term sealing application. The current study has additional consideration of fluid aging for a long-term operation to conventional FEA analysis of packer rubber studied by Zheng et al 16,17 and Chen et al 18 The proposed FEA methodology by chemical aging is not limited to the size of the elastomer shape and can be readily extended to develop a successful operation limit for various elastomer applications in the energy industry.…”

“…Development of a rubber packing element for a 105 MPa /215 C deep well test packer was reported, and it is qualified by mathematical model simulation and experiment. 18 These studies did not consider chemical degradation to validate sealing performance.…”

Structure Design and Sealing Performance of Downhole Emergency Packer

“…To reduce the occurrence of blowout accidents, the packer can be installed on the drill pipe when running down the well. In case of downhole overflow, the emergency packer can effectively prevent the high-pressure liquid in the lower annulus from flowing to the wellhead, and prevent the annulus from the packer to the wellhead from high pressure, thus reducing the probability of blowout and wellhead operational risk [2].…”