Sustainable Two-In-One Fluid System for Drilling and Cementing Processes

Abstract This research focuses on developing a multipurpose fluid that functions as both a drilling fluid and cement. It addresses the persistent challenge of incomplete displacement caused by residual mud in the wellbore during traditional cementing operations. This fluid initially acts as a drilling mud but can be activated to solidify into cement. Residual fluid in the wellbore also hardens, ensuring complete displacement and improving cementing efficiency. This study introduces a unified fluid system that can be utilized for both drilling and cementing, eliminating the need for separate formulations. The proposed drilling fluid formulation uses sustainable materials, with blast furnace slag as the primary weighting agent, combined with various additives to achieve superior performance in rheology, fluid loss control, SAG resistance, and low free fluid. Upon activation with a specific agent, the fluid transitions into a solid. The strength of the solidified material is evaluated using Ultrasonic Cement Analyzers (UCA) and Unconfined Compressive Strength (UCS) tests. Test results demonstrate that the multipurpose fluid exhibits excellent rheological properties prior to activation. For an 11 ppg formulation, the API HPHT fluid loss is less than 10 ml, with a filter cake thickness below 3/32 inches. The SAG factor of 0.5 indicates outstanding stability. After activation, the system maintains low viscosity initially and then transitions rapidly into a high-strength solid, making it highly suitable for field applications. Within approximately 4 hours, the compressive strength exceeds 500 psi and surpasses 1500 psi within 24 hours, as measured by an Ultrasonic Cement Analyzer (UCA). Notably, no free water is observed in the activated fluid. This study presents a low-density fluid system for drilling and cementing. Activated with a simple alkaline agent, it transitions into a high-strength solid for cementing and zonal isolation. Made with furnace slag, it offers excellent rheology, fluid loss control, and SAG stability, ensuring cost-effective, integrated applications.