Effect of Well Down Spacing on EUR for Shale Oil Formations

Abstract

Abstract With the shift in focus towards unconventional oil and gas as the future of the oil and gas industry, it has become essential to optimize performance of wells in these formations and ensure economic feasibility in these unpredictable scenarios. Down Spacing of wells is a procedure by which we reduce the space between the laterals of two wells to maximize recovery from the formation. In conventional reservoirs, due to the homogeneity in petro-physical parameters of the formation, down spacing is usually not economic as the lower number of wells would also be sufficient to achieve optimum productivity, furthermore, the wells will have a tendency to cannibalize each other's production. However, in unconventional reservoirs like shale, down spacing becomes essential to maximize reserves and the productivity from them as poor permeability hinders majority of the pores to be reached by a relatively lower number of wells. The presented paper, achieves to find the optimum down spacing distance that can be achieved between two fractured lateral wells in Eagle Ford Shale Play. The paper analyses the performance of group of wells with different well spacing in the Eagle Ford formation. The data used is from the public forum. The EUR/well is calculated using decline curve analysis. Fekete-Harmony has been used for calculation of EUR and then a simplistic cash flow analysis had been conducted to analyse the feasibility for each presented scenario. This paper also has a group of analog wells created in Fekete Harmony with drilling and completion techniques similar to the ones widely used in Eagle Ford Formation. Real world Eagle Ford geological and petrophysical parameters are incorporated into the Harmony model for the analysis of these wells. This paper emphasizes on the need for downspacing in the shale oil reservoirs for optimum production. It also discusses the advantages and disadvantages of downspacing as well as looks into the economic side of this process.