井下液力复合加压器的结构改进与力学分析

Structural Modification and Mechanics Analysis of Downhole Composite Hydraulic Thruster

目前的单级液力加压器行程太短,加压效果并不明显,多级液力加压器在实际钻井作业中柔性较大,易发生柔性弯曲,并且制造成本较高。为此,从经济和功能2方面综合考虑,对液力加压器结构进行改进,利用增压缸与单向流通阀相结合,实现双重加压和减振功能,进而研制了液力复合加压器。对液力复合加压器进行了结构设计和力学性能分析。分析结果表明:液力复合加压器利用钻头喷嘴的结构特点,将压差加压的单一加压方式改为复合加压模式,不仅具有复合加压功能,而且能够存储瞬时的液压能,减振效果比原有加压器更明显,减振过程储存的液压能为再次加压提供了更加有利条件。所得结论为解决大位移井和水平井的假钻压问题提供了方案。

The current single-stage hydraulic thruster has the disadvantages ol short stroke and non-obvious thrust effect. The multistage hydraulic thruster has high flexibility in the actual drilling operation, which is prone to flexible bending. In view of this, comprehensively considering the economic and functional aspects, the existing hy-draulic thruster structure has been modified. Combining the booster cylinder and the check valve, duplex pressuriza-tion and vibration reduction function could be achieved, and a composite hydraulic thruster device has been devel-oped. The structure has been designed and mechanical properties have been analyzed for the composite hydraulic thruster. The results show that, by means of the structural characteristics of the drill bit nozzle, the composite hydrau-lic thruster allows a composite thrust mode instead of single thrust mode, and additional function of instantaneous hy-draulic energy storage could also be attained. The vibration reduction performance is more obvious than the original device, and the stored hydraulic energy during the vibration process provides more preferable conditions for re- pres-surization. The conclusion provides a solution for the weight stacking issue in extend reach wells and horizontal wells.