Abstract
Calcium carbonate is the most predominant scale in Saudi Aramco crude producers. Conventional phosphonate based scale inhibitor treatments are highly effective in carbonate formations. Application of new research findings in the company’s modified scale inhibitor squeeze treatment programs has significantly improved the treatment life at the lowest possible cost. These modifications resulted in better post-squeeze well response compared to more conventional treatment. However, in spite of the success of scale inhibitor treatment in vertical and conventional horizontal wells, addressing the placement of chemicals in long horizontal and complex producers, such as multilateral, maximum reservoir contact (MRC) and extreme reservoir contact (ERC) wells is always challenging and cost intensive.
A drop in operating pressure at a gas-oil separation plant (GOSP) from 450 psig to 250 psig in a carbonate field necessitated a proactive scale inhibitor treatment program. A comprehensive scale mitigation study was conducted to prioritize the treatments based on the severity of the scaling potential for all the vertical, deviated, horizontal, multilateral, and MRC wells as part of the company’s scale mitigation strategy. Conventional bullheading of chemicals from the surface into all laterals and selective lateral treatment after comprehensive lateral testing was executed as part of the trial test campaign. This paper describes/illustrates well selection criteria for priority treatment methods applied for simple to complex wells, comparison of pre- and post-production results, and a discussion of the current ongoing optimization program.
