This article, written by Senior Technology Editor Dennis Denney, contains highlights of paper SPE 159089, ’Horizontal Pressure-Sink-Mitigation Completion Design: A Case Study in the Haynesville Shale,’ by Robert C. Martinez, SPE, Josh Rosinski, SPE, and Doug Dreher, SPE, Exco Resources, prepared for the 2012 SPE Annual Technical Conference and Exhibition, San Antonio, Texas, 8-10 October. The paper has not been peer reviewed. Pressure sinks caused by production from an initial well can impair future completion effectiveness unless steps are taken to mitigate the effects. Pressure sinks exist in an area that was stimulated previously or has a reduced pore pressure, which then creates a path of least resistance for a subsequent nearby stimulation. Pressure-sink-mitigation (PSM) techniques are vital for successful Haynesville shale development. PSM techniques applied to Haynesville shale wells represent a potential breakthrough on how to mitigate the effects of pressure sinks effectively and increase the ultimate gas recovery of the unit. Introduction The Haynesville shale-gas play covers the east Texas/north Louisiana border area (Fig. 1). Hydraulic-fracture stimulation is critical to produce natural gas from the nanodarcy-permeability rock. Initial designs used a hybrid treatment (i.e., conventional job) that included a slick water pad followed by low concentrations of 100-mesh sand spaced with slick water sweeps. Fracture modeling showed that these hybrid treatments created very long fracture half-lengths. Fig. 2 shows how wells producing as far as 1 mile in an east-northeast/west-southwest orientation from an ongoing fracture treatment often would exhibit a pressure response during the fracture treatment of the offset well. This well interaction was the first indication that a hybrid slickwater treatment could be influenced by pressure sinks. Early in the development program, 80-acre offset wells were drilled to evaluate infill-well performance. A conventional completion design and a PSM design (PSM 1) were used on the off-set wells, and performance was reduced significantly. This reduced performance was not limited to 80-acre offset wells. When designing around pressure sinks, production from an existing well within a 1-mile radius could affect performance significantly, and could risk several wells in a development plan. Subsequent stimulations had a similar effect on offsets during and after the stimulation. It became apparent that different completion designs would be needed.