Numerical simulation on the effect of pore pressure gradient on the rules of hydraulic fracture propagation

Autor: Weiyong Lu, Changchun He
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Energy Exploration & Exploitation, Vol 39 (2021)
Druh dokumentu: article
ISSN: 0144-5987
2048-4054
01445987
DOI: 10.1177/01445987211009389
Popis: To clarify the influence of pore pressure gradient on hydraulic fracture propagation, the stress distribution in and around the borehole is explained by theoretical analysis method in this paper. A mechanical model of hydraulic fracture initiation under the action of pore pressure gradient is established. Then coupled seepage-stress-damage software is used to simulate the initiation and propagation of hydraulic fractures in rock samples under the action of pore pressure gradient. Finally, the influence of the number and spatial position of the induction holes on the initiation and propagation of hydraulic fractures is analyzed. It is shown that: (1) Pore pressure gradient can effectively reduce the initiation pressure of hydraulic fractures. (2) The greater the pore pressure gradient is, the easier the hydraulic fracture is to spread to the region with high pore pressure. (3) With the action of pore pressure gradient, the hydraulic fracture is shaped as ‘丨’, ‘丿’ and ‘S’ types and can be represented by the four abstract conceptual models.
Databáze: Directory of Open Access Journals