Scale deposits are controlled now with liquid inhibitors

Abstract

The use of liquid inhibitors to control scale deposition in fractured formations is discussed. Laboratory tests were conducted in order to observe the precipitation of calcium sulfate and calcium carbonate upon addition of calcium chloride, sodium sulfate, or sodium carbonate to sodium chloride solutions. Following these precipitation tests, the effects of chemical inhibitors were then determined. Other tests were used to measure the adsorption of an organic phosphate and a polyorganic acid on silica. The results of these tests are tabulated. Methods are then discussed for placing liquid inhibitors in fractured formations surrounding producing, injection, or disposal wells. Several methods for detecting inhibitors have been investigated, both in the laboratory and in the field. Case histories involving chemical fracture-squeeze treatments in 3 wells are also discussed.