Research and Application on Adaptability of the Flexible Sealing Element for Unconventional Reservoirs Fracturing

Abstract

The study on the flexible sealing element for separate layer fracturing in tight oil reservoirs was researched in order to meet the urgent developing requirements of deep volcanic gas reservoirs in Daqing Oilfield and tight oil reservoirs in Hailar–Tamtsag Oilfield. The traditional NBR rubber in the oilfield cannot meet the high technical requirements in the wells (120–180 °C, 50–100 MPa), or wells with CO₂, H₂S, and other chemical additives, etc. Therefore, the rubber formula made from HNBR and AFLAS with favorable anti-chemical corrosion and temperature and pressure-bearing performance are modified for use in the hostile environment. Meanwhile, the selection of various additives, the optimization of the vulcanization process, the geometric structure design, the hardness combination and the relation between the setting force and the sealing differential pressure of flexible sealing element and its protective parts are studied to innovatively develop the flexible sealing element which can resist the temperature of 150–180 °C and pressure of 100 MPa for separate layer fracturing in the deep volcanic gas reservoirs. The study not only indicates a step up in the field of recovering oil from the deep gas and tight oil reservoirs, but also promotes the integration of the horizontal open hole wells completion and multi-sectional fracturing for the deep gas wells and provides the reference for water injection and production technology in the domestic oil field and the overseas.

Copyright 2017, Shaanxi Petroleum Society.

This paper was prepared for presentation at the 2017 International Field Exploration and Development Conference in Chengdu, China, 21–22 September 2017.

This paper was selected for presentation by the IFEDC&IPPTC Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper, as presented, have not been reviewed by the IFEDC&IPPTC Committee and are subject to correction by the author(s). The material does not necessarily reflect any position of the IFEDC&IPPTC Committee, its members. Papers presented at the Conference are subject to publication review by Professional Committee of Petroleum Engineering of Shaanxi Petroleum Society. Electronic reproduction, distribution, or storage of any part of this paper for commercial purposes without the written consent of Shaanxi Petroleum Society is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of IFEDC&IPPTC. Contact email: paper@ifedc.org or paper@ipptc.org.