Field Application of Chelatants in the Handling of ASP-Flooding Produced Fluid

Abstract

Summary Suspended-solid (SS) particles in the produced water of the X2M alkaline/surfactant/polymer (ASP) flooding project were separated by membrane filtration and identified to consist mainly of alkali-earth-metal carbonates and silica precipitates. A compound formulation of chelatants was developed to stabilize the water phase of ASP-flooding produced fluid and prevent or reduce precipitation of both alkali-earth-metal carbonates and silica. The compound chelatant was put into a limited field trial in the surface production system of the X2M ASP-flooding project to evaluate its effects on the quality of treated produced water. The average SS content of treated ASP-flooding produced water was decreased to below the 20-ppm SS specification limit for reinjection by a dosage of chelatant at 480 ppm or higher. Scale-removal performance of the compound chelatant was also observed during the field trial.