Numerical modeling of multiple fractures competition propagation in the heterogeneous layered formation

Abstract

Separate-layer fracturing technology is one of the key stimulation technologies in the multi-layer reservoirs However, multiple fractures cannot evenly propagate due to the strong heterogeneity of the layers. In this paper, a three-dimensional model considering heterogeneity and fluid partitioning is developed to simulate the competitive propagation of multiple fractures in heterogeneous layered formation. The fracture pressure, fracture morphology, fluid volume and fracture length were systematically analyzed under different heterogeneous physical parameters. The following conclusions were obtained: (1) Formations with high rock strength, low permeability or high horizontal minimum principal stress will increase the fracture pressure and reduce the fluid volume within the fracture and fracture length. (2) Hydraulic fractures are easy to propagate into the interlayers if the pay zones have high rock strength and low permeability. (3) In heterogeneous layered formations, hydraulic fractures are more likely to gain competitive advantage in the high Young’s modulus and high permeability formations, while have the disadvantage in the high rock strength and high minimum principal stress formations. Poisson’s ratio has a little effect on the fracture propagation. This paper provides some helpful design guidance for the separate-layer fracturing in the heterogeneous layered formation.

Keywords

• Fossil energy
• Layered formations
• Hydraulic fracturing
• Fracture propagation
• Numerical simulation