Predicting Carbonate Scale in Oil Producers from High Temperature Reservoirs

Abstract

Abstract Calcium carbonate scale is a common problem in the oil industry leading to reduced well performance and obstruction of the safety valves. Recent field experiences indicate that scaling may be a problem at lower Saturation Ratio (SR) than earlier anticipated. In a high pressure, high temperature Scale Cell crystal growth in synthetic formation water has been studied. Induction times and growth rates have been determined using a microscope cell. The results have been interpreted using nucleation theory. The findings indicate that wells may be safely operated at SR below 2.5 at 85°C. At higher temperature crystal growth is less dependant on SR and the temperature dominates the system. Care should therefore be taken when operating wells at temperature above 100°C.