Thomas Hagen

Scale Squeeze Treatments in Short Perforation and High Water Production ESP Wells - Application of Oilfield Scale Management Toolbox

Inhibitor squeeze treatments have been regularly carried out to prevent both sulphate and carbonate scale depositions from reservoir to topside facilities in North Sea field since 1990s. Some of the wells, especially for the short perforation, high water production wells and relatively clean sandstone with little amount of clay material, had experienced a relatively short squeeze life with traditional squeeze treatment. In this paper, an oilfield scale technology toolbox has been introduced to meet the challenge of squeeze treatment for high water production and short perforation ESP well, including scale inhibitor molecular design, squeeze life enhancement technique, squeeze design, inhibitor residual analysis technique, application and deployment techniques. Field trials were carried out with a satisfactory result. This paper outlines the idea of how a special monomer was introduced into a polymer to provide improved inhibition performance and enhanced adsorption and retention capability, along with squeeze life enhancement technique through crosslinking and bridging capability with other ionic polymer additives. In addition, the squeeze life enhancement techniques through squeeze treatment design, residual analysis and deployment are discussed. A detailed lab test program to qualify the squeeze scale inhibitors will be introduced including brine compatibility, static jar test, dynamic loop test and coreflood test to qualify the scale inhibitor for squeeze application. This polymer scale inhibitor showed good efficiency in both sulphate and carbonates scale inhibition under the test conditions, along with very good adsorption and desorption property without formation damage. This paper will give a comprehensive study of oilfield scale squeeze treatment for challenged well, which includes molecular synthesis, program of lab qualification, field design, deployment, application and monitoring. In addition, the mechanisms of squeeze life enhancement through molecular design, squeeze life enhancement and squeeze design will be addressed.