Research On The Screw Down-hole Supercharger Of Improving The ROP

With the development and application of ultra high pressure jet technology, Hydraulic mechanical joint rock breaking drilling technology has aroused wide concern, people have begun to study the down-hole supercharger.Most of them adopt the research route of the underground part of the hydraulic booster, although they have made some achievements, they have not reached the site application conditions. Because the existing booster has a set of complex hydraulic reversing mechanism and reliability is low; and the underground space is limited, working condition is poor, complicated structure is easy to cause accidents. Therefore, developed a new type of downhole pressure unit is very necessary.This paper combines the existing mature downhole power-- screw drill, puts forward a kind of new screw downhole pressure speed device and screw drill as the power source. The device can make the rotary motion of the screw drill into straight reciprocating motion of the plunger, thereby making the part of drilling fluid into the pressure chamber be ultra high pressure fluid. Firstly, based on the in-depth study of ultra high pressure water jet assisted rock breaking mechanism, through a variety of pressurization scheme comparison, determined the overall scheme of screw supercharger speed device, and finished three-dimensional modeling of the units with Pro/ENGINEER; secondly, according to the structure parameters of screw drill tool, suitable specification of the screw is determined through theoretical calculation, and the structure is improved; thirdly, finished the structure design and strength check of the important parts on the reversing and pressure mechanism, and finished the finite element analysis of the plunger and the plunger cylinder by ANSYS, meeting the design requirements; also the detailed design of the plunger high-pressure sealing structure is finished, the the sealing material and sealing properties are discussed; then, according to the design pressure and flow of high pressure, determined nozzle diameter, and selected the structure of nozzle, and calculated the optimal contraction angle of nozzle by ANSYS; finally, according to the design requirements,writted the test plan. Based on the research above, finish machining drawings and assembly drawings etc..