Development of an Oil-Based Gravel-Pack Carrier Fluid

Abstract Operational problems arise when wells drilled with synthetic/oil-based reservoir drilling fluid (S/OB-RDF) systems are completed using traditional water-based gravel pack carrier fluids. Fluid compatibility, formation wettability and filter cake cleanup have to be addressed, along with the cost of prolonged rig time, for displacements and pit cleaning. There is significant potential for oil-based gravel pack carrier fluids for completing openhole horizontal wells drilled with S/OB-RDFs. Oil-based carrier fluids may minimize compatibility issues, reduce rig time, and provide a means for filter cake cleanup. At a minimum, oil-based gravel pack carrier fluids should: Carry and suspend gravel at downhole temperatures Provide density up to 13.5 ppg for well control Be compatible with standard oil- and synthetic-based muds and additives. An oil-based gravel pack carrier fluid with these fluid characteristics has been developed. The fluid system is formulated using a low aromatic base hydrocarbon, a heavy brine formulation (e.g. NaCl, CaCl2, CaBr2, K-formate.) and a surfactant. Results indicate that the fluid system is stable under shear, has good gravel suspension characteristics and has a low formation damage potential. Yard test data demonstrate the feasibility of the fluid system when used in conjunction with shunt screen technology.