Study On Design And Configuration Of Dilution-based Dual Gradient Drilling System

In deepwater drilling,the conventional drilling technology is not economical and exist a big risk.Dual gradient drilling technology can effectively solve the drilling problems encountered in conventional drilling in deepwater drilling.In this paper,combined with the project of Sinopec-key techniques research of deepwater dual density drilling(JP14012),we conducted the research of DBDG drilling system configuration design and configuration research that suitable for deep water of the south China sea,the main research contents are as follows:(1)The principle research of DBDG drilling technologyAnalyses the working principle of DBDG drilling technology,combined with the characteristics of deep water drilling working environment of the south China sea,we proposed technical scheme of DBDG drilling system that suitable for deep water of the south China sea,the technical scheme included the overall realization scheme ?diluent selection scheme and the main technical characteristics etc.we conducted the research of drilling well body structure design and optimization of DBDG drilling.(2)The research of diluent injection technologyBy means of hydraulic parameters calculation dilution density,injection rate and other parameters,to select injection pump and research the layout plan of injection pipeline and select the best scheme,to design the solution of Injection pipe joint,to research injection method and the required equipment of below the seabed mud,completed system design scheme of diluent injection system.(3)The diluent separation recycling technology researchResearch the separation principle of wellhead which contained diluent and drilling cuttings,through the analysis of mixture of liquid solid phase,formulated dilution process for separating and recovering,proposed dilution separating and recovering schemes,and optimized of separation and recovering key equipment,carried out the theoretical simulation analysis of recovery efficiency,and optimized the operating parameters of the key equipment,complete system design of dilution separation and recovery.(4)Study on DBDG drilling system engineeringInvestigation and analysis of conventional solid control equipment technical parameters and characteristics of the existed drilling platform,demonstrated the feasibility of the DBDG drilling to the existed drilling platform and give the corresponding solution.According to the principles of the national standard and the offshore equipment layout,divided the existing platform and arranged the corresponding regional equipment,ultimately determined the overall scheme of the key equipment of the dilution.