Research And Application Of Variable Frequency Electric Drive Mud Pump For Deep Hole Geological Core Drilling

Mud pump is one of the key equipment in geological core drilling which is known as the "heart" of drilling rig.And its performance will directly affect the quality,efficiency,cost and safety of drilling.In recent years,with the complexity of deep-hole geological core drilling formation and the diversification of construction technology,as well as the development of digital and intelligent well site construction.The traditional BW series mud pump has some problems,such as poor matching of performance parameters,complicated structure design,short service life of vulnerable parts,inconvenient operation and maintenance,and inaccurate parameter monitoring.The goal of this paper is to design and development of new frequency conversion electric drive mud pump——BW-300/16 DB type mud pump,in order to satisfy deep hole geological core drilling technology.By means of theoretical calculation and analysis,computer aided design and experimental study.Its working characteristics and advantages are analyzed and studied.First,according to the actual working conditions of deep-hole geological core drilling,based on the relevant calculation theory of fluid mechanics and the mud circulation pressure model,the flow rate and pressure of the mud in the hole during the small diameter deep hole rope coring drilling are analyzed and calculated,which provides working condition basis for performance parameter design of mud pump.Secondly,according to the requirement of deep hole geological core drilling technology on the performance of mud pump.Based on the comparison and analysis of the traditional mud pump's structure performance and speed regulation mode,the traditional BW-300/16 mud pump is upgraded to BW-300/16 DB mud pump by frequency conversion technology.The stepless adjustment between working points of mud pump is realized and the working area is increased.Thirdly,according to the overall technical scheme of the new mud pump,through the study and improvement of the speed regulating system,control system,the whole machine structure and the vulnerable parts,such as valve,cylinder liner,piston cup,etc..The improvement design of the virtual prototype is completed by using Autodesk Inventor(2012)three-dimensional design software.Stress analysis was carried out on key parts such as crosshead,the crankshaft,connecting rod and so on,which improved the reliability of the design.The comprehensive performance and working efficiency of the mud pump are improved.Lastly,a prototype of BW-300/16 DB variable frequency drive mud pump is manufactured,and the comprehensive performance of the new variable frequency drive mud pump designed and developed is verified by the mud pump test bench type test and the drilling project test of well Qiandi 4.Through preliminary test and verification,the variable frequency drive mud pump breaks through the limitation of traditional mud pump in the aspects of process parameter matching,man-machine control,life of fragile parts and operation energy consumption.It embodies the functional advantages that are combined with the applicability and equipment development trend of deep hole geological core drilling technology.This paper also lays a good foundation for further research and application of the new variable frequency drive mud pump.