A Study of Fracture Penetration Law of Tight Sandstone Gas Reservoir in Block LX

Abstract

The fracture of tight sandstone gas reservoir in Block LX is characterized by thick sand body and thin gas layer. The production layer is adjacent to water layer and coal fracture, and the longitudinal stress difference of the shielding layer is small. Based on the theory of fracture tip stress intensity factor, this paper adopts core experiment and theoretical analysis method, combined with fracturing engineering geological characteristics and construction parameters, to analyze the fracture penetration criterion and study the influence of construction factors and reservoir geological characteristics on the law of fracture penetration law. The results show that the minimum horizontal principal stress difference of artificial fracture passing through the interlayer is affected by the construction displacement, reservoir thickness and other factors; The construction displacement has obvious influence on the minimum horizontal principal stress when the artificial fractures pass through the interlayer, and the construction with small displacement can prevent the artificial fractures from passing through the interlayer when the stress difference of the reservoir interlayer is less than 3.5MPa. The minimum horizontal principal stress difference of the reservoir layer when the artificial fracture extends to the interface of he reservoir layer can be determined by using the criterion of the artificial fracture behavior and the model of the artificial fracture behavior, which will provide some technical guidance for the field hydraulic fracturing construction.