What is the Acceptable Cluster Interference Degree in Multistage Hydraulically Fractured Wells?

Abstract

Abstract The cluster spacing was set up to 700 ft in diffrent shale formations including Bakken and Barnet shales. Howerver, tight cluster spacing was applied in apart in Eagle Ford and DJ Basin for cluster spacing up to 15 ft. The tight fracture spacing was applied to ais to increase the initial production rate. However, a higher initial production rate is at the expense of higher operation and completion costs in addition to operational complexity. This study presents an combined workflow to calculate the percent of interference and its effect on the well performance in addition estimate the acceptable interference degree that provides the highest well profitability. Analytical rate transient analysis (RTA) and reservoir numerical simulation were combined to estimate the ratio of the effective fracture surface area (ACe) for hydrocarbon production to the actual stimulated fracture area (ACa) from the numerical simulation. The degree of interference was calculated by (1- ACe/ACa). The economic study was added to the integrated workflow to estimate the degree of interference and the optimum spacing based on the profitability of the well. This study presents an integrated workflow to quantify the degree of cluster interference as a function of spacing. The workflow was integrated with an economic model to estimate the acceptable interference percent to have a higher NPV. The higher the stage number and tighter cluster spacing, the higher the cluster interference will be. The acceptable interference percent is a function of formation properties and economic parameters. The acceptable interference percent was found to be 16% in the case of 0.0001md, 2.5$/Mscf. Increasing the formation permeability increases the acceptable interference percent to accelerate production and increase the recovery. As the gas price increases, tighter spacing is recommended, where, at 8$/Mscf, the NPV was continuously increasing up to the lowest spacing in this study of 20 ft. This study provides an integrated workflow to quantify the interference percent and the acceptable percent as a function of cluster spacing, formation properties, and economic analysis in order of increasing the well profitability.