Research On Continuous Circulation Drilling Tools

Continuous circulation drilling technology can effectively overcome downhole pressure fluctuation caused by starting or stopping pump,and decrease the risk of underground complex situation and accident due to the underground pressure fluctuation.It especially benefits the pressure sensitive wells,high angle wells,large displacement wells,deep wells,underbalanced wells,and narrow density windows wells.In recent years,the continuous circulation drilling technology has been paid more and more attention because of its advantages.From the historical development of continuous circulation drilling technology,there are two ways to realize the continuous circulation drilling wells.This paper describes the working principle of the two kinds of technology and equipment.And after the analysis of domestic drilling equipment and valve manufacturing,the writer design and manufacture a set of continuous circulation drilling tools.The core three-side continuous sub is composed of a ball valve and a side valve.And a designed fast connection tools and other matched transition manifold and some ground control systems,make continuous circulation drilling operation is reasonable.At last by fast and reliable continuous circulation drilling operation ensure downhole mud equivalent circulation density stability,and reduce the occurrence of downhole complicated conditions and accidents.Through the experiment of continuous circulation drilling tool,after repeated modification and test performance of the tools for sealing,strength,function,etc.,the final field test was finished on Xinggu7-H173 wells,and it is proved that the continuous circulation drilling tools and its supporting process in this paper can realize drilling without stopping pump.Compared CCS continuous circulation system controlled at the wellhead,continuous circulation drilling tools developed in this paper has the advantages of simple structure,convenient operation,rapid flow conversion,small pressure fluctuation,maintain pressure stability,etc.It provides a powerful tools for the realization of continuous circulation drilling.