An operator drilling in the Gulf Coast sandstone formation in Harris County, Texas experienced gas influxes and mud losses in the 8 ½-in. hole section at 12,337-ft. The operator was forced to continue circulating a 16.2 lb/gal water-based mud (WBM) to maintain well control. While continuing to circulate, the operator was losing 30 barrels each hour. The operator only had another 550 feet to drill to reach total depth (TD) in the vertical well.
The operator needed to increase the mud weight to 16.5 lb/gal to stop the gas influx and drill to TD. The drilling fluid consultant contacted Impact Fluid Solutions to use STAR SHIELD to enable the drilling fluid service provider to extend the mud weight window of the WBM system. Impact recommended 5 lb/bbl of STAR SHIELD wellbore stability additive to prevent further mud losses and allow the operator to weight up without induced losses and stop the gas influx.
After treating the whole system with 5 lb/bbl of STAR SHIELD, the operator was able to increase the mud weight to 16.5 lb/gal which stopped the gas influx without further losses. The operator drilled to TD, ran casing and cemented the casing without losses.