To stimulate a reservoir efficiently, multistage plug-and-perf completion and fracturing technologies are widely utilized to create multiple hydraulic fractures along a horizontal wellbore. However, excessive field cases and lab tests evidenced that, the simultaneous initiation and propagation of multiple fractures within a stage could compete with each other, cause uneven fluid and proppant partition into each placed cluster. Resulting in low cluster efficiency and non-uniform fracture development. Solid particulate diverters can aid to influence the fluid distribution between open clusters to optimize stimulation efficiency. The objective of this study is to use numerical models to thoroughly investigate the functionality of particulate system in fracturing process and optimize the completion and stimulation strategy under specific downhole conditions.
In this study, both CFD-DEM model and a 3D fracture simulator are employed to model fluid diversion and fracturing process for wells completed with plug-and-perf technique. For a field case study, sensitive analyses were performed to quantify the impact of completion design and pumping strategy on the resulted stimulation efficiency. The overall conductive reservoir volume is predicted to compare the cluster efficiency between different design scenarios. Thereafter, the stimulation efficiency of placed perforation clusters is analyzed and optimized with engineered solid particulate diverters.
For the presented particulate diversion technique, both in-stage and inter-stage fluid diversion are operationally feasible. From our analysis, engineered solid particulate diverters can effectively plug the active perforation clusters and build-up enough pressure to divert fracturing fluid into non-active perforation clusters to create additional fractures. Proper number of diverter pills and adequate pumping schedule can boost the cluster efficiency and eventually increase the conductive reservoir volume.
Through a field case study, the presented geomechanical analyses showed that the diverter design and operational parameters can be customized to enhance cluster efficiency. By adjusting completion design, the usage of particulate diverters can be optimized accordingly to maximize the stimulation efficiency. With the proposed efficient design, all the planned perforation clusters can develop and propagate hydraulic fractures and contribute to the overall production.