Research On Hydro-Seat For Wireline Coring Tool Inner Tube

With the increase of resources consumption and the decrease of surface resources,China has regarded explore deep mine as a strategy.Diamond wireline coring tool has been applied for deep drilling owing to the less trip of inner tube.However,the deeper we drill the ground,the more complex the stratum will be.The Wireline coring technology will appear a number of disadvantages when we drill the complex stratum.For example,the inner will be jamming easily and latch will break down further.Then,the inner tube can't be retrieved which will lower the efficiency of drilling.This thesis focuses on innovative design of locating mechanism of wireline coring tool and verify the feasibility of hydro-seat wireline coring tool in some complex stratums.First of all,the author investigate and survey the designs of locating mechanism of wireline coring tool for domestic and overseas companies and put forward the hydro-seat solution for inner tube of wireline coring tool on basis of these designs.Then,the author introduces the structures and working principle of hydro-seat mechanism.We can find the variational pressure difference laws of nozzle and the orifice by calculating the calculation model that established by author.Then we can get the hydraulic force laws for the whole hydro-seat mechanism with the change of structure parameters and quantity of drilling fluid.On condition of the size of nozzle and orifices,the author concludes that hydraulic pressure will increase with the close of orifices outlet in same quantity of fluid and hydraulic force will increase with the increase of quantity of fluid in same open of orifices.Secondly,the author simulates pressure differences of several diameters of orifices in different quantities and opening by ANSYS Fluent and carry out laboratory tests for some orifices.Then we can get the local resistance coefficient of orifices and amend the empirical value.Finally,four working conditions that may occur when hydro-seat wireline coring tools drilling are analyzed,and the resistance that the inner tube assembly may encounter when drilling in complex formations is analyzed and theoretically calculated,mainly including Clay layer,watersensitive stratum and fractured stratum are drilled,the friction resistance generated by the core and core tube.The friction resistance is analyzed and calculated using soil mechanics theory and force balance equation,and the upper part of the core liquid and the core tube are connected with each other.The pressure generated by the pressure difference between the outer pipes and core is calculated using empirical values.The structural parameters of the hydro-seat wireline coring tool are designed,and the hydraulic force of the inner pipe assembly is calculated when the orifices opening of the drilling fluid is different under different pumping quantities of the designed coring tool.According to the resistance encountered when drilling into different formations,the drilling state of the drill was verified by force,and the applicable range of the drill was obtained.