Productivity-Index Behavior for Hydraulically Fractured Reservoirs Depleted by Constant Production Rate Considering Transient-State and Semisteady-State Conditions

This paper introduces a new approach for studying productivity-index (PI) behavior of fractured oil and gas reservoirs during transientand pseudosteady-state conditions. This approach focuses on the fact that PI derivative could vanish at a certain production time, indicating the beginning of pseudosteady state, wherein the PI demonstrates constant value. The reservoirs in this study are considered depleted by horizontal wells intersecting multiple hydraulic fractures where Darcy flow and non-Darcy flow may control flow patterns in the porous media. The PI is calculated assuming constant production rate and considering pressure profile for early- and intermediate-production time when transient condition dominates fluid flow and late-production time when pseudosteady state is reached