The Design Of New Type Of Hydraulic Torsion Impactor And Its Dynamic Simulation

As the shallow oil and gas resources are increasingly depleted, the development of oil and gas drilling are more into the deep formation. PDC bit is generally used in deep well with hard formation at present, but the stick-slip vibration phenomenon can be easy to appear in the process of drilling, it can lead to the low drilling efficient and short service life of bit, hole anomaly and so on. Studies have shown that torsional impact drilling technology can effectively alleviate the stick-slip vibration phenomenon of PDC bit. However, the research of torsional impact drilling technology in China started relatively late, the torsional impact drilling tool main refer to foreign research data, its work performance is not very ideal. So based on the previous studies, this paper designs a new type of hydraulic torsion impactor, its outer diameter is 0180mm and can control the flow between 18 to 38 L/s, then study it in terms of theory and simulation.The work of this paper is as follows:(1) Analyze the effect of torsional impact drilling tool to the PDC bit, complete the whole structural design of new type of hydraulic torque impact. Point out three problems should be solved, such as how to achieve the power, how to design dynamic impact group and how to purify the mud. Then modeling the dynamic impact group, analyses the working principle of its hydraulic drive through its different position state, and know that it would experience four kind of state in a period of motion, verify the rationality of structural design;(2) To produce the driving liquid and form high and low pressure chamber in the dynamic impact group, use the orifice to control the flow rate and pressure difference act on dynamic impact group, and through the required torque estimate the required flow rate. Then design the short hole form of orifice based on its theory, and then put forward two kinds of design scheme of orifice in hydraulic torque impact. The one is use single size of orifice, the other is use various sizes of orifice. Finally determine the optimal scheme and orifice size according to flow field simulation, and through the flow rate by simulation estimate the collision torque and frequency;(3) Collision simulation of dynamic impact group was applied in Adams to analyze the elastic collision between hydraulic hammer and spindle, use the impact model and build constraint. Get that hydraulic hammer has impact and bounce state and dissipation of energy in the collision process. Then analyze the change of torque and time under different angular velocity. And then make the statics analysis to it and get the stress distribution and displacement by impart torque to hydraulic hammer, make sure its structural design can satisfy the strength requirement;(4) Because the solid phased particles in drilling fluid can hinder the normal operation of dynamic impact group, so design a axial inlet type of solid-liquid separating unit which is composed of vortex inducer,vortex body and orifice sleeve. Then determines the size of each structure and the blade of vortex inducer. Simulate the solid-liquid two-phase flow which is based on RSM turbulent model to get the velocity schematic, pressure field and the distribution of volume fraction of solid particles. And then analyze the separation efficiency of separating unit of different size underflow and different particle size.The main results of this paper are as follows:(1) Solve the problem of how to achieve the power, confirm use four sizes of orifice to control different flow rate. Then estimate the collision torque is 1402-2048 N·m, the collision frequency is 15-21Hz;(2) Collision simulation is applied to dynamic impact group, draw the conclusion that collision torque is increasing with angular velocity increasing, collision time is decrease with angular velocity increasing. And find that the collision torque is 1750-2158 N·m, the collision time is about lms. Then strength analysis is carried out to find out the maximum stress is happened on the Hydraulic hammer, the value is 385.53MPa, satisfy the strength requirement;(3) Design a new type of solid-liquid separating unit and simulate the two-phase flow to realize the feature of internal flow field. Then analyze the separation efficiency and realize that the flow rate have little impact on it, but it increasing with the size of underflow increasing, and to the solid particles of large particle size the separate efficiency will be better.Through the above research work, have a deeper understanding to the new type of hydraulic torsion impactor. The scheme selection of orifice and design form of solid-liquid separating unit have its innovativeness, the collision simulation to the dynamic impact group is not common. The conclusions have certain reference value to the later related research.