Experimental Investigations and Optimizations of Rheological Behavior of Drilling Fluids Using RSM and CCD for Gas Hydrate-Bearing Formation

In this research work, the effects of hydrate inhibitors on the rheological behavior of drilling fluids were thoroughly analyzed for gas hydrate-bearing formations under the ocean floor conditions. Initially, base drilling fluids were prepared using carboxy methyl cellulose, polyanionic cellulose, xanthan gum, calcium carbonate and potassium chloride. Further, three kinetic inhibitors and two thermodynamic inhibitors were added in these base drilling fluids to maintain the rheological characteristics for optimum drilling performance at low-temperature conditions. Response surface methodology in conjunction with the central composite design was utilized to evaluate and optimize the drilling fluid combinations to get the desired response in terms of apparent viscosity at different temperatures. The software analyzed the data and optimized drilling fluid combinations for gas hydrate formation in offshore conditions. The optimized drilling fluids have shown desired results which may be used for the drilling of gas hydrate-bearing formations.