Development of polymer gel systems for lost circulation treatment and wellbore strengthening

Abstract

Lost circulation is a frequent problem and a significant contributor to the non-productive time (NPT) in the drilling operation. Field reports and experimental studies have revealed that conventional solutions are doomed to fail in many complex loss situations. Factors such as fracture sizes, depth, temperature, pressure, and type of formation, complicate the problem and limit the lost circulation materials (LCM) options. The primary objective of this research was to develop a flowing crosslinked polymer-based drilling fluid by introducing a gelling polymer and a crosslinker to the LCM and drilling mud formulations. The goal is to enhance wellbore strength by increasing the fracture resistance of weak formations to avoid potential mud losses. Other objectives of this research covered developing different fast-curing LCM pills to treat lost circulation in challenging situations. Different types and combinations of polymers, crosslinkers, and reinforcing nanoparticles were utilized. Further, in this research, machine learning (ML) algorithms were used to assess the relationship between the crosslinked polymer recipes and drilling fluids additives. The ML approach aims to expand the developing study and to open more opportunities for this work to be efficiently applied in the field. The novelty of this study is in the use of the organic and inorganic crosslinker in controllable gelling polymeric LCMs that can seal near wellbore fractures and stable unconsolidated formations. Besides, this research introduces a new concept of gelation kinetics of polymeric gels in drilling fluids. This concept and the post-experimental analysis conducted in this study are essential for the petroleum industry to develop new lost circulation preventive and corrective methods.