Openhole versus Cemented Completions for Horizontal Wells withTransverse Fractures: An Analytical Comparison

摘要

Horizontal wells that are to be stimulated with transverse fractures are usually completed either openhole with annularisolation packers or cemented. Fluid communication is established by perforating or using stimulation sleeves. The industrycontinues to grapple with several issues regarding these completions, such as what the optimum number of fractured intervalsis, and which approach (openhole versus cemented) provides the best hydrocarbon production.Analysis was performed to create a simple method for determining the production impacts of increasing the number offractured intervals in a horizontal well. The intent was to create something similar to the McGuire-Sikora curves (method ofdetermining the production impacts of fracturing vertical wells) for horizontal wells with transverse fractures. Using theMcGuire-Sikora curves allows for a quick assessment of productivity gains associated with fracture stimulating a verticalwell.Analysis was performed using a two-dimensional reservoir simulator using a steady-state edge drive. A methodology wasdeveloped, and is described, for including the effects of vertical to horizontal permeability ratios in a two-dimensionalsimulator.Analytical results showed productivity-index ratios as a function of relative conductivity for different fracture geometries.The resulting curves were used to estimate production gains of fracture stimulation compared to the openhole, unstimulatedcase. The variables included in the analysis were reservoir permeability, vertical to horizontal permeability ratio, reservoirthickness, reservoir length, fracture half-length, fracture width, fracture permeability, fracture spacing along the horizontal,and openhole and cemented completions.In this paper, comparisons are made to published works that use production data and microseismic data to compareopenhole and cemented completions. The analysis presented should help fuel the industry debate of whether cementedcompletions are an overused solution.