A new approach for well test analysis of wells wit hfinite conductivity fractures

摘要

Analyses of variable flow rate tests have been given special attention recently because it is generally impractical to deep a constant flow long enough in the field to perform a drawdown test,in additon to wellbore storage that affects early-time data in may situations.For fractured wells,this early-time period represents linear or bilinear flow in fractures.Thus,it is veryimportant to devise a technique that would allow a petroleum engineer to obtain reservoir characterstics in addition to fracture characteristics such as fracture conductivity and fracture hald-length,using this early flow data. In this paper,a new analysis method is developed to describe drawdown and buildup tests for wells intersected by finite conductivit fractures,This new method utilizes thesuperposition metod to arrive at a solution for downhole pressure versus time using simultaneously measured downhole pressure and sandface rates.Analysis based on the solution of this new method allows one to calculate directly obthreservoir and facture characteristics.Results obtained are verified by solving two field examples to demonstrate the model capabilities.A step-by-step procedure for analysis is also presented.