井下叶栅偏心块质量优化技术研究

井下叶栅转动使得套管串产生偏心公转振动,套管偏心公转改变了井内环空流体的运动状态,使井内流体产生周向流动实现紊流顶替,改善了窄边顶替效率和固井质量。建立了偏心叶栅作用下井下套管串偏心公转振幅计算模型,分析了不同公转振幅条件下环空流体的旋流速度,在此基础上根据偏心块质量与套管公转振幅之间的关系,对不同井深处实现环空紊流顶替的偏心块质量进行了优化,从而为不同井深处井下偏心叶栅结构的优化设计提供必要的依据。

A Study on the Optimizing Technology of the Quality of Downhole Cascade Eccentric Block

The rotation of downhole cascade makes the casing string produce eccentric revolution vibration.The eccentric revolution of casing string changes motion state of fluid in annular space and makes the fluid produce circumferential flow to realize turbulent displacement.Thus improve displacement efficiency in the narrow side and cementation quality. This paper established eccentric revolution amplitude calculation model of the casing string under the action of downhole eccentric cascade. It analyzed swirling flow velocity of annular fluid under the condition of different revolution amplitude. Thus according to the relationship between the quality of eccentric block and revolution amplitude of the casing string,it optimized the quality of eccentric block in different well depth to realize annular turbulent displacement. Then provide necessary basis for optimizing eccentric cascade structure design in different well depth.