Performance evaluation and field verification of a selective water plugging agent

Abstract

Given the low plugging success rate of existing plugging agents in oilfield applications, this study proposed a new selective plugging agent system (SA-1-S) with a high plugging efficiency, which dissolves in oil and releases oil flow channels under formation temperature conditions. Being insoluble in water and acid, it blocks water flow channels. In particular, at ambient temperature of 25 °C and reservoir temperature of 65 °C, the dissolution rate of SA-1-S particles in formation crude oil, kerosene, and diesel oil exceeded 96%, being suitable for formations at temperatures below 120 °C∼130 °C. The proposed agent’s plugging rate exceeded 90% on cores and 80% under reverse kerosene action; this rate dropped under forward scouring by 2.01 ∼ 3.21%. The selective water plugging agent proposed in this paper has application prospects in improving the oil recovery in high water-bearing oil wells.