Simulation And Calculation Of Key Parameters In Dual Gradient Drilling

Compared with the land drilling,the use of traditional drilling methods for deepwater drilling operations are facing many difficulties:available deep water drilling rigs,small pressure window,gas invasion and so on.Double gradient pressure control drilling technology is a new drilling technology solution for the above-mentioned deepwater drilling problem.CML double gradient drilling is an important branch of the drilling technology solution.Its key operating parameters include wellbore pressure,drilling fluctuation pressure,pump displacement,annular drilling fluid level,etc.These key operating parameters affect construction safety And the main factors of operating costs,the current lack of the corresponding theoretical calculation model.Based on this,the key parameters of the new double gradient drilling-CML double gradient drilling in double gradient drilling are the main research contents.This paper first studies the development of double gradient drilling pressure drilling technology both at home and abroad,and through research,it has not been studied in China for CML double gradient drilling.Then,this paper studies the process principle,process flow and ancillary equipment of CML double gradient pressure drilling technology,and discusses the difference between the technology and other double gradient drilling drilling and the applicable environment of the technology.Under different working conditions Numerical simulation of the key parameters of the double gradient drilling:calculation of the annular pressure drop at the time of drilling and the liquid level of the annular drilling fluid;When the gas pressure is used,the AUSMV model is used to calculate the parameters such as pump displacement,annulus pressure,pump pressure,annular pressure,gas-liquid ratio and overflow.The simulation results show that the drilling fluid with the same density can be used to cope with the downhole pressure change under different working conditions,and even without the drilling fluid,it is necessary to increase the drilling fluid.On the basis of theoretical research,based on VS2013 and C#language software development,the final development of a double gradient drilling calculation and analysis software,the use of the software can be based on the basic data,under different conditions CML double gradient drilling simulation and calculation,The calculation results will be used to guide the key parameters of CML double gradient drilling,and provide reference for CML double gradient pressure control drilling engineering engineering design and construction,and contribute to the safe application and popularization of double gradient pressure control drilling technology.