Fluid flow modeling in multi-stage hydraulic fracturing patterns for production optimization in shale reservoirs

Abstract

Horizontal drilling and multi-stage hydraulic fracturing are the key technologies enabling the oil and gas industry to unlock unconventional resources. As verified often with the utilization of microseismic data, hydraulic fracturing in shale reservoirs typically creates highly complex fracture networks due to their complex geology and the activation of the pre-existing natural fractures that cannot be realistically captured when the classical planar bi-wing fracture models are implemented. Coupling proper geomechanical models with microseismic data helps better reflect the fracture complexity that is anticipated to enhance production performance. Recently, new stimulation design patterns have been proposed for production optimization using this approach by coupling the fundamental geomechanics concepts in order to waive the stress interference constraint of the minimum fracture spacing and to produce further fracture complexity in the altered stress regions. The aim of this study is to evaluate and compare two new stimulation patterns, namely, the Alternate and the Zipper, to the Consecutive multi-stage stimulation pattern from a fluid flow perspective using a dual permeability numerical model. The study considers anticipated fracture complexity and Stimulated Reservoir Volume (SRV) overlap of parallel lateral wells. An economic evaluation is also conducted to couple the flow-based optimization with the Net Present Value (NPV) analysis to quantify costs vs. benefits of selecting a specific stimulation pattern. Another focus area of the research is the flowback behavior study of the Consecutive stimulation pattern for several rock types after various well shut-in times. Results of this research demonstrate how the configuration of fracture stages, complexity of fracture networks and SRV overlap impacts the production performance and eventually NPV of the studied stimulation patterns. The comparison study highlights the governing parameters and provides insights on the significance of developing and optimizing a stimulation pattern utilizing fluid flow evaluation. The flowback behavior study helps to understand how the water imbibition mechanism, driven by capillary forces during the well shut-in period, impacts the early time production performance and water load recovery.