Title: Transient pressure behaviour of multi-stage fractured horizontal well in stress-sensitive coal seam

Authors: Ren Zongxiao; Qu Zhan; Jiang Huayi; Lou Erbiao; Zhang Jiaming; Yao Ze; Yang Hongbin

Addresses: College of Petroleum Engineering of Xi'an Shiyou University, Xi'an 710065, China ' College of Petroleum Engineering of Xi'an Shiyou University, Xi'an 710065, China ' College of Petroleum Engineering of Xi'an Shiyou University, Xi'an 710065, China ' Tarim Oilfield, Ku er le 841000, China ' CNPC Economics and Technology Research Institute, Beijing 100724, China ' CNOOC Research Institute, Beijing 100028, China ' School of Petroleum Engineering, China University of Petroleum, East China, Qingdao 266580, China

Abstract: As an alternative energy of conventional resources, coalbed methane (CBM) has been studied globally. So far, the pressure distribution model for multi-stage fractured horizontal well (MFW) in stress sensitive coal seam is almost solved by numerical method. In this paper, a transient pressure behaviour model of MFW was established. Using perturbation transformation, Laplace transform, image theory and superposition principle the mathematical model was solved. According to the result of calculation, the flow process of MFW can be identified as six regimes. Stress-sensibility primarily influences the latter five stages. The well bore dimensionless pressure drop is several times larger comparing with the situation that does not take the stress sensitive into account. Accordingly, the influences of some of the critical parameters on the transient pressure behaviour were studied, including the fracture number, permeability modulus, storage ratio, and so on. [Received: August 25, 2016; Accepted: October 9, 2017]

Keywords: coalbed methane; stress sensitive; fractured horizontal well; source function; flow regimes.

DOI: 10.1504/IJOGCT.2019.102785

International Journal of Oil, Gas and Coal Technology, 2019 Vol.22 No.2, pp.163 - 187

Accepted: 09 Oct 2017
Published online: 07 Oct 2019 *

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