Development of High-Temperature and High-Mineralization-Resistant Adaptive Plugging Agent and Its Performance Evaluation

Abstract

Most of the existing drilling fluid plugging agents fail in the high-temperature and high-mineralization environment of deep formations, and the drilling fluid will enter the deep part of the formation along microfractures and fractures, causing a series of downhole complications and accidents, which seriously affects the safety and efficiency of drilling and results in great economic losses. It is important to develop a high-temperature and high-mineralization-resistant plugging agent to effectively plug the formation for the development of deep oil and gas. In this paper, an adaptive plugging agent ADS is prepared by emulsion polymerization using 2-acrylamide-2-methylpropanesulfonic acid, N,N-dimethylacrylamide, and styrene as raw materials, which is resistant to high temperature and high mineralization in water-based drilling fluids, and is resistant to temperature up to 180 °C, sodium salt resistant to saturation, and calcium salt resistant to 5%. It has less influence on the rheology of the drilling fluid system.

Preparation and Evaluation of Nanopolymer Microsphere Plugging Agents for Ultrahigh-Temperature Water-Based Drilling Fluids

“…The two methyl groups on the amide group in DMAA increase the spatial site resistance and enhance the rigidity of the molecular chain. It also reduces the polarity of the amide group, is unfavorable to the forming of hydrogen bonds with water molecules, and the high-temperature hydrolysis stability is enhanced, which may boost the polymer from temperature resistance. − Furthermore, the synthetic PSDA has a certain deformation capacity, which allows it to enter and plug pore joints.…”