Title: Preventing gas migration after hydraulic fracturing using mud cake solidification method in HTHP tight gas well

Authors: Jun Gu; Hangxian Gao; Pin Gan; Penghui Zeng; Jiahe Chen; Haiyang Hao

Addresses: Department of Petroleum Engineering, Faculty of Earth Resources, China University of Geosciences, Wuhan, Hubei 430074, China ' Exploration Branch, China Petroleum and Chemical Corporation (SINOPEC), Chengdu, Sichuan 610041, China ' Department of Petroleum Engineering, Faculty of Earth Resources, China University of Geosciences, Wuhan, Hubei 430074, China ' Exploration Branch, China Petroleum and Chemical Corporation (SINOPEC), Chengdu, Sichuan 610041, China ' Exploration Branch, China Petroleum and Chemical Corporation (SINOPEC), Chengdu, Sichuan 610041, China ' Department of Petroleum Engineering, Faculty of Earth Resources, China University of Geosciences, Wuhan, Hubei 430074, China

Abstract: The mud cake solidification (MCS) at cement-formation interface (CFI) is a key to improve the liner cementing quality and zonal isolation ability for preventing gas migration after hydraulic fracturing in high temperature high pressure (HTHP) tight gas wells. This paper introduces a new method of MCS, consisting of mud cake solidification agents (MCSAs) (GJE-I and GJE-II) as spacers in front of cement slurry. When the curing time is 3, 7 and 15 days at 132°C and 21 MPa, compared with the conventional method, the bond strength at CFI was improved by 907.16%, 829.57% and 988.45%, respectively. Moreover, the compatibility of MCSAs meets the requirements for liner cementing operation of HTHP tight gas wells. The field application shows that the qualified ratio of cementing quality is 100%, the ratio of high quality is up to 90.00% and the gas migration rate after well cementing and hydraulic fracturing decrease rapidly to zero. [Received: January 3, 2018; Accepted: June 3, 2018]

Keywords: HTHP tight gas well; hydraulic fracturing; gas migration; liner cementing; zonal isolation; mud cake solidification agents; MCS method; cement-formation interface.

DOI: 10.1504/IJOGCT.2020.106150

International Journal of Oil, Gas and Coal Technology, 2020 Vol.23 No.4, pp.450 - 473

Accepted: 03 Jun 2018
Published online: 24 Mar 2020 *

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