Research On Simulation Technology Of Reaming While Drilling

With the peak period of oil field exploitation in the east of China having passed,the exploration and development of oil and gas resources in recent years will be developed to the deep west.Due to the special geological conditions in the western region,necking and stuck drilling will occur in the actual drilling process.In order to effectively solve these problems,the drilling and hole expansion technology has been applied.However,in the field operation,it is found that the eye expander is prone to violent vibration during rock cutting,which leads to the wear of cutter wings and affects the drilling efficiency,and even causes premature failure of drilling tools in serious cases.These problems seriously restrict the development and application of the drilling and reaming technology.Through field experiments,it was found that suitable drilling pressure distribution and downhole drilling tools combination can effectively improve the vibration of the hole expander.However,the previous method of calculating the drilling pressure ratio was too single and could not consider various parameters comprehensively;in addition,today’s understanding of the drilling tool combination of the follow-on borehole reaming is not clear,and it is impossible to combine the drilling tool combination with the actual drilling parameters.For this reason,it is necessary to conduct a systematic study on the drilling pressure and torque distribution relationship between the lead expansion holes and the downhole drilling tool combination.In this thesis,the relationship between rock drillability and mechanical drilling speed on the drilling pressure and torque distribution of the drill bit in the lead expansion hole is studied based on the PDC single tooth cutting force model.When the rock drillability increases,the total drilling pressure and drilling pressure ratio of the collar reaming bit increase;when the mechanical drilling speed increases,the total drilling pressure of the collar reaming bit increases,and the drilling pressure ratio is basically unchanged.A finite element model was established according to the drilling column dynamics to study the vibration characteristics of the hole reamer and the drill column below it.The simulation results show that the vibration of the eye expander is the most intense in the drilling and reaming system,and the vibration intensity of the drill column below the eye expander decreases as it moves away from the eye expander.The effects of rock drillability,mechanical drilling speed,drill column speed and lead spacing on the vibration characteristics of the eye reamer were studied.When the rock drillability,mechanical drilling speed and drilling column speed increase,the vibration of the eye reamer becomes more intense;the increase of the spacing of the leading eye reamer makes the vibration of the eye reamer decrease first and then increase.Taking the stabilizer as the research object,the influence of the number and installation position of the stabilizer on the vibration characteristics of the eye expander was studied.Under the conditions of this paper,the vibration of the eye expander is smaller as the number of stabilizers increases;the suitable installation position of the stabilizers can effectively reduce the vibration of the eye expander.