RESEARCH ON DEEPWATER SYNTHETIC BASED DRILLING FLUID

With the technology advancement,the offshore oil exploration and exploitation are being approached from shallow sea to deep sea,even to the ultra-deep sea.Deepwater drilling fluid technology is one of the key technologies on deepwater drilling,the main problems of deepwater drilling fluid are low temperature rheological property and gas hydrate.In order to solve the technical problems,the deepwater liner alpha olefin synthetic based drilling fluid formulation was optimized by laboratory experiment,and the low temperature rheological property of synthetic based drilling fluid was researched by simulating deepwater operation temperature.The results showed that the viscosity of drilling fluid increased with the temperature decreasing,but the 63 rpm readings and dynamic tangential force of drilling fluid nearly weren't affected by temperature conditions.The gas hydrate formation ability of optimized deepwater synthetic based drilling fluid was studied at the pressure of 20MPa and the temperature of 0℃ by DSC(Differential Scanning Calorimetry) technique,the results showed that there was no gas hydrate formation.The laboratory results showed that the drilling fluid's properties of resistance to temperature,inhibition,and the ability of reservoir protection were better.