Modeling the proppant fines mobility on productions trends for hidraulic fractured wells

Abstract

In general terms, hydraulic fracturing is the physical -mechanical process of creating fractures in the formation in order to provide highly conductive flow channels to accelerate the total production. To this end, the injection of a highly viscous polymer fluid accompanied by particulate material called proppant material whose main function is to keep open the fissures in the rock.

The application of efforts by the rock that comes into contact with the fracture proppant material begins a crushing process. This phenomenon gives rise to the gradual appearance of proppant fines, which have the ability to be transported and deposited spatially throughout the proppant pack, thereby generating affected areas with partial obstruction or total highly conductive channels. This process occurs throughout the productive life of the fracture and has its greatest influence during the execution of chemical stimulation treatments through the proppant pack.

This study presents a new engineering approach that enables quantification of the impact generated by the mobilization and redistribution of the proppant fines banking on altering the effective fracture conductivity and its associated production. A Single Well Model (SWM) was created using Local Grid Refinement (LGR) to represent the partial fracture conductivity reduction, this model allowed to recreate the different distribution patterns in order to obtain the production trends after a remedial chemical stimulation event. The results show percentages of detrimental production between 9 to 30% compared to the base case production. The results indicate that the effect of the various distribution patterns of form caused by the re-mobilization of proppant fines banking generates significant and sustained levels of production reduction. This negative factor should be minimized during the well intervention involving the injection of fluid along the deteriorated fracture. In addition, it was found that this type of interventions, not only must be performed at matrix injection rates, but also considering a control strategy similar to those used in wells with high production of formations fines.