Production Review of Current Stimulation Techniques in the Jonah Field

Abstract

Abstract Since the discovery of the Jonah field in 1977, many styles of hydraulic fracturing treatments have been employed to stimulate the Lance formation. Commercial production was not established in the field until the early 1990s, and technological improvements have permitted increased production since that time. Further trials of fracturing techniques, including slickwater fracs, induced stress diversion, and flow-through composite fracture plugs, continued over time. Since March 2010, channel fracturing treatments have been employed in the Lance formation in conjunction with more traditional, conventional fracturing treatments. For the purpose of this paper, conventional fracturing treatments consist of either crosslinked gel or slickwater fracturing treatments. The proppant is added in a continuous manner with an increasing proppant concentration. For crosslinked gel treatments, the typical proppant is 20/40 -mesh white sand added up to a maximum of 6 lbm/gal. For the slickwater treatments, the typical proppant is 40/70- or 30/50- mesh white sand added up to a maximum of 3 lbm/gal. The channel fracturing treatments use a pulsed method of adding the proppant to the fluid. Instead of adding the proppant continuously, the proppant is turned on and off in approximately 15-second time intervals. This concept is intended to provide high-conductivity, unpropped open flow paths through hydraulic fractures held open by the proppant pillars. To assess the effectiveness of the channel fracturing method in the Jonah field compared to conventional fracturing treatments, a spatial sampling technique was used. Spatial sampling is a documented method for comparing large groups of wells with their direct offsets. The original intent of the spatial sampling method was to identify underperforming wells; however, the method has also been employed as a way to compare various completion or stimulation techniques. In this case, spatial sampling was applied in an attempt to evaluate the effectiveness of the channel fracturing technique compared to conventional fracturing techniques using continuous proppant addition during the treatment. Five discrete areas of the Jonah field were included in the study. Only wells completed in the same time frame as the channel fractured wells were included. The treatment and production data for all wells were obtained from public sources. There might also be differences in production among the conventionally fractured wells, depending on whether a crosslinked or slickwater treatment was used; however, the effect of slickwater treatments, as opposed to crosslinked treatments, was not considered in this study.