Case Study: Isolation and Restimulation of Granite Wash Zone in Mendota, NW Field Using Inflatable Packer Frac Liners

Abstract

ABSTRACT The Mendota, NW (Granite Wash, SW) field in east central Roberts, County, Texas produces gas and gas condensate from the Cherokee Granite Wash section. Due to multiple producing intervals spread over a long vertical section, many of the wells in this field were fracture stimulated using the "limited entry" diversion technique1. Later comparison of actual gas recovery versus volumetrically calculated gas-in-place indicated very low gas recovery for wells originally stimulated by limited entry. It was concluded that some of the zones in these wells did not receive adequate treatment and would benefit from restimulation. In order to fracture stimulate individual zones in wells with multiple open producing intervals, it is necessary to isolate the individual zone to be treated from the other open intervals. For the first well in the study area to be restimulated, a frac liner was configured utilizing two inflatable packers straddling a segment of tubing covering the upper producing intervals. This enabled fracture stimulation of the deepest zone with the treatment pumped down the casing and through the short liner interval, allowing an adequate injection rate with a reasonable injection pressure.