Research On The Vibration Characteristics Of The Reaming While Drilling Tool System And The Influence Law Of Reaming Process Parameters

Hole-Enlargement-While-Drilling(HEWD)is the key technology to solve wellbore shrinkage and formation creep in slim hole,deep well and ultra-deep well.It can optimize casing program,improve drilling and cementing efficiency,and reduce cost.At present,most of researches on HEWD were still in the aspects of reamer designs and bottom hole performance(BHA)selections.And they didn,t consider the interaction of HEWD's tools and the dynamic characteristics of HEWD 's BHA in different conditions.In this paper,an analysis model is established to analysis the vibration characteristics of HEWD's BHA and the influence of HEWD's parameters on vibration of HEWD's BHA in the foundation of rock drillability,rock breaking,drill string dynamics and numerical simulation technology.The main points of this paper are listed as followings:(1)The development of reamers and the research status of HEWD's BHA dynamics are investigated,and the research content and methods are determined.(2)The dynamic model of HEWD,s BHA is established based on the actual well path,the interaction among reamer,bit and rock and the contact between BHA and wellbore,and the numerical simulation model is established based on the dynamic model.The reliability of the numerical simulation model is verified by comparing with the measured data in the field.(3)The characteristics of axial,transverse and stick slip vibration are analyzed to reveal the vibration of HEWD's BHA,the vibration intensity of HEWD's BHA different position is compared,and the risk points are indicated.(4)The influence of rock drillability,drilling parameters and BHA on vibration of HEWD's BHA is analyzed,and the laws of influence are revealed.The laws can provide reference data for the further development of mitigation measures.The characteristics of vibration of HEWD's BHA and The influence of HEWD's parameters on vibration of HEWD's BHA are studied in this paper.This work is helpful to understand the vibration of HEWD's BHA and can provide reference data for the further development of mitigation measures.