Awakening an Old Field—A Case Study of a Refracturing Program in the Greater Green River Basin

Abstract

Summary Restimulation of wells completed in the Frontier Formation, a low-permeability (e.g., 0.01–0.05 md) gas sand, has proved to be successful in the Fontenelle Field. The field is east of the Fon-tenelle reservoir, on the LaBarge Platform in the western part of the Greater Green River Basin in southwestern Wyoming. In this area the majority of hydrocarbon reserves in the Second Frontier are produced from the massive shoreface sandstones locally known as the Second Bench of the Second Frontier (Kf22b). To date, Berco Resources, LLC has increased reserves in the Fontenelle Field by restimulating four wells producing from the Frontier Formation with massive hydraulic fracturing treatments. Because of the success of these treatments, another operator in an offset area to the north has also successfully implemented a Frontier refracturing program. This paper summarizes the refracturing program and the success which Berco Resources, LLC has realized. The candidate selection process is examined, as well as operational considerations when restimulating old wells. The stimulation treatments and fluid systems are also investigated. Daily/monthly production data consisting of gas, condensate, and water rates along with well head pressures are evaluated for all cases with fractured well type curves, the pseudoradial flow specialty plot (Δp/q vs. log t), and a production simulator comparing actual versus modeled production rates. Finally, the impact of the refrac-turing treatments on economic return is presented. The success of the refracture treatments has led to a new drilling/completion program in the Fontenelle Field in 2006 by an operator that recently acquired theBerco Resources, LLC properties.