Plastic Waste as a Sustainable Loss Circulation Material for Preventing Fluid Loss in High-Permeability Formations

Abstract Lost circulation is a common problem that happens during drilling in formations that are fractured, vugular, and have high permeability, which can lead to excessive fluid loss, rig downtime, and complications with well control. Previously, conventional LCMs such as calcium carbonate and nutshells were widely used, but they present challenges in cost, environmental footprint, and local availability. This study investigates the use of plastic waste particles, specifically high-density polyethylene (HDPE), as a sustainable loss circulation material (LCM) in water-based drilling fluids. In this work, plastic packaging waste was repurposed without chemical, thermal, or mechanical treatment. Materials were sourced from two different post-consumer streams, then manually cleaned and sieved to obtain particle sizes below 500 µm, appropriate for bridging and sealing high-permeability pore networks and microfractures. No synthetic processing or modification was performed, making the approach simple and scalable. Three mud systems were prepared and evaluated: a base formulation, a reference sample with calcium carbonate, and a modified system where calcium carbonate was fully replaced by HDPE. HPHT filtration tests (200 °F, 500 psi) using 120 µm ceramic discs were conducted to assess fluid loss, along with full rheological profiling. A separate LCM test using a slotted disc setup further confirmed the sealing ability of the plastic particles under pressure. The results show that plastic waste particles formed effective seals and reduced fluid loss more than calcium carbonate. Mud stability and rheological performance were preserved. The sealing efficiency depended on particle size compatibility with the loss zone aperture. This work demonstrates that HDPE waste can serve as a low-cost, effective LCM and provides a viable pathway for plastic reuse in drilling operations, contributing to circular economy goals and waste reduction.