Investigating the simultaneous fracture propagation from multiple perforation clusters in horizontal wells using 3D block discrete element method

Abstract

Multi-cluster horizontal well fracturing is one of the key technologies to develop the unconventional reservoirs such as shales. However, the field data shows that some perforation clusters have little production contribution. In this study, a three-dimensional (3D) numerical model for simulating the multiple fracture propagation based on 3D block discrete element method was established, and this model considers the stress interference, perforation friction and fluid-mechanical coupling effect. In order to determine the most appropriate measures to improve the uniformity of multiple fracture propagation, the effect of the geologic and engineering parameters on the multiple fracture propagation in shale reservoirs is investigated. The modeling results show that the geometry of each fracture within a stage is different, and the outer fractures generally receive more fracturing fluid than the interior fractures. The vertical stress almost has no effect on the geometries of multiple fractures. However, higher horizontal stress difference, larger cluster spacing, smaller perforation number, higher injection rate, and smaller fracturing fluid viscosity are conducive to promote the uniform propagation of multiple fractures. The existence of bedding planes will increase the fluid filtration, resulting in a reduction in fracture length. The middle two fractures receive less fluid and the width of them is smaller. Through analyzing the numerical results, a large amount of fracturing fluid should be injected and the proppant with smaller size is suggested to be used to effectively prop the bedding planes. Cluster spacing and perforation number should be controlled in an appropriate range according to reservoir properties. Increasing the injection rate and reducing the viscosity of fracturing fluid are important means to improve the geometry of each fracture.

Numerical study of hydraulic fractures propagation in deep fracture-cavity reservoir based on continuous damage theory

“…Huang performed simulation to study the interaction between hydraulic fractures and gravels in glutenite formation based on 2D particle discrete element method, and results showed that the non-uniformly distributed stress field caused by the existence of glutenite maily affects the fracture propagating path (Huang et al, 2023b). Although the reservoir types studied are different and the methods used are also varied, these studies have reached similar conclusions regarding the expansion behavior of hydraulic fractures in fractured reservoirs (Song et al, 2017;Tan et al, 2017;Huang et al, 2019;Song et al, 2020;Tan et al, 2020;He et al, 2023;Liu et al, 2023;Wu et al, 2023). They all agreed the significant influence of reservoir heterogeneity and geostress states on the propagation path of hydraulic fractures, as well as the control effect of fracturing fluid flow rate and viscosity on the morphology of hydraulic fracture propagation.…”

Research on geophysical response analysis and prediction technology of geostress in the shale gas area of the southern Sichuan Basin

“…For geostress, many theories, methods, and applications are still in the exploratory stage (Yang et al, 2013;Song et al, 2017;Song et al, 2020;Liu et al, 2023). Geostress is a key factor affecting shale hydraulic fracturing design (Huang et al, 2019;Zheng et al, 2022;Huang et al, 2023a;He et al, 2023;Tan et al, 2023). Meanwhile, understanding geostress is a prerequisite for successful development of shale gas (Tan et al, 2017;Luo et al, 2022;Zhang et al, 2022;Huang et al, 2023b).…”

Mechanisms of Hydraulic Fracture Propagation and Multi-well Effect during Multiple Vertical Well Fracturing in Layered Reservoirs with Low Permeability

“…The rapid development of numerical methods and computer technology provides an effective way to study hydraulic fracture propagation in large-scale low-permeability reservoirs and compensates for the shortcomings of experimental research. − In recent years, many researchers have employed numerical methods to create large-scale three-dimensional (3D) fracturing models to study the behavior of fracture propagation during multiple horizontal well fracturing. , The effects of well spacing, perforation parameters, fracturing sequences, and horizontal stress differences on fracture propagation have provided a theoretical basis for optimizing horizontal well cluster spacing. − Large-scale fracturing models effectively solve the problem of size bottlenecks in the experimental specimens. Research on the fracture propagation law based on large-scale models can contribute to a better understanding of the mechanism of hydraulic fracture propagation in the field. − …”

“…24−26 In recent years, many researchers have employed numerical methods to create large-scale three-dimensional (3D) fracturing models to study the behavior of fracture propagation during multiple horizontal well fracturing. 27,28 The effects of well spacing, perforation parameters, fracturing sequences, and horizontal stress differences on fracture propagation have provided a theoretical basis for optimizing horizontal well cluster spacing. 29−34 Large-scale fracturing models effectively solve the problem of size bottlenecks in the experimental specimens.…”