The total loss of fluid during drilling continues to plague the oil and gas industry. For many reasons, the various technologies that have attempted to combat this severe issue have been unsuccessful. In Middle East drilling operations, carbonate and limestone formations pose difficult geological conditions, such as naturally occurring fractures and vugular and/or cavernous zones. These troublesome zones are the primary reason for additional costs, including increased drilling non-productive time. The lack of an efficient, controllable solution has led operators to implement complicated and potentially risky drilling practices to access the targeted depths of many wells in the area.

A Right-Angle-Setting Composition (RAS-Co) has been developed to provide the industry an efficient solution for plugging and isolating specific problematic zones. The RAS-Co is engineered to remain at a low fluid viscosity (18–30 cP) during placement and quickly react to bottomhole temperature in a consistent and controllable manner. The instant transition in viscosity from a thin fluid to a rigid composite lets the technology be mixed at the rig site, pumped through any drillstring configuration, and spotted/placed in any suspected loss zone—thereby eliminating further fluid losses. The innovative RAS-Co can be applied in two different versions. The dual-pill version can be used in zones up to 400°F (~204°C) wherever water-based fluids are being used. This version is deployed like a standard ‘gunk squeeze’ application. The time-delayed single pill version can be used where both non-aqueous and water-based fluids are being used at up to almost 300°F. It can tolerate up to 50% contamination with water or drilling fluids, and will not invade the formation. Both versions can be removed with acid. The chemical formula of RAS-Co is customized to offer a versatile, yet controllable solution that is effective for stopping even the most severe lost circulation events.

Key advancements made during the developmental stage (laboratory data) are presented, as well as several successful field applications of the engineered, fluid composition.

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