Title: A novel model of initial fracture pressure in fractured formation

Authors: Yi Ding; Pingya Luo; Xiangjun Liu

Addresses: State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China ' State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China ' State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China

Abstract: Initial fracture pressure is basic parameter in design of hydraulic working. In fractured formation, abundant natural fractures increase complication of predicting initial fracture pressure. Without accurate initial fracture pressure, reservoir stimulation efficiency will be impaired. Therefore, in this paper, in combination with shear and tensile strength criterion in multiple natural fracture planes condition, a new fracture initiation model has been established. Based on this model, influence factors of fracture initiation have been analysed. Results indicate that initiation type could be tensile or shear failure along fracture plane, decreasing the initial fracture pressure. Initial fracture pressure is related to fracture occurrence and its decline becomes large due to increasing fracture number. With multiple natural fractures, initiation is totally controlled by natural fracture. In the application, results of this model are good consistent with oilfield data. Thus, this model can offer guidance for hydraulic fracturing. [Received: May 22, 2017; Accepted: June 19, 2018]

Keywords: fractured formation; natural fracture; hydraulic fracture; initial fracture pressure.

DOI: 10.1504/IJOGCT.2020.106706

International Journal of Oil, Gas and Coal Technology, 2020 Vol.24 No.1, pp.18 - 35

Received: 03 Mar 2018
Accepted: 19 Jun 2018
Published online: 20 Apr 2020 *

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