Use of inhibitors for scale control in brine-producing gas and oil wells

摘要

Field and laboratory work have shown that calcium-carbonate scale formation in waters produced with natural gas and oil can be prevented by injection of phosphonate inhibitor into the formation, even if the formation is sandstone without calcite binging material. Inhibitor squeeze jobs have been carried out on DOE's geopressured-geothermal Gladys McCall brine-gas well and GRI's co-production wells in the Hitchcock field. Following the inhibitor squeeze on Gladys McCall, the well produced over five million barrels of water at a rate of approximately 30,000 BPD without calcium-carbonate scaling. Before the inhibitor squeeze, the well could not be produced above 15,000 BPD without significant scale formation. In the GRI brine-gas co-production field tests, inhibitor squeezes have been used to successfully prevant scaling. Laboratory work has been conducted to determine what types of oil field waters are subject to scaling. This research has led to the development of a saturation index and accompanying nomographs which allow prediction of when scale will develop into a problem in brine production.