The research of fracture prolongation, closure mechanism and flow conductivity evaluation for water-fracs

Article type: Research Article

Authors: Zhang, Li gang^{a; b; *} | Qu, Si ning^a | Lv, Yun shu^{a; c} | Li, Shi bin^a | Guan, Bing^a

Affiliations: [a] Petroleum Engineering, Northeast Petroleum University, Hei long-jiang Daqing 163318, China | [b] College of Engineering and Applied Science (CEAS), University of Cincinnati, USA | [c] Petroleum Engineering, Technische Universität Clausthal, Clausthal-Zellerfeld 38678, Germany

Correspondence: [*] Corresponding author. E-mail: zhangligang529@163.com.

Abstract: Water-fracs is a key technology to increase yield and injection in low permeability oil and gas field, while it has a certain limitation. The application of the water-fracs mainly depends on the flow conductivity provided by self-supporting fracture in reservoir. The steering, slipping and closing processes of self-supporting fracture are simulated with the finite element simulation method under the consideration of the rock heterogeneity, deviation stress, the angle between fracture initial direction and maximum principal stress direction, and the irregular curve fracture. The sensitivity factors and effect rules of the angle of the direction of crack growth and slipping distance are obtained,and the formation mechanism of fracture conductivity is revealed. The preparation method of the wall combination of the self-supporting fracture indoor and the test method of the flow conductivity under different closure pressure are established. The result provides a theoretical foundation for the water-fracs increasing production mechanism and the appropriate reservoir conditions.

Keywords: Water-fracs, the angle of the direction of crack growth, slipping distance, flow conductivity, self-supporting fracture

DOI: 10.3233/SFC-170202

Journal: Strength, Fracture and Complexity, vol. 10, no. 2, pp. 117-127, 2017