All-metal downhole motor based on multi-stage double-plunger-eccentric gear mechanism

Abstract

The invention discloses an all-metal downhole motor based on a multi-stage double-plunger-eccentric gear mechanism. The downhole motor comprises a flow distribution shaft, an outer pipe and a multi-stage eccentric gear driving mechanism which are coaxially arranged, wherein the flow distribution shaft is suspended and supported in the outer pipe through the multi-stage eccentric gear driving mechanism. According to the novel rotary plunger type downhole motor hydraulically driven by drilling fluid, the plunger structure is high in machining precision, low in cost and good in plunger type dynamic sealing effect; the torque is transmitted through a planetary gear train with an eccentric structure, so that the working efficiency of the downhole motor is improved. The downhole motor driven bythe multi-stage double-plunger-eccentric gear mechanism adopts an all-metal structure and is resistant to the high-temperature environment; the plunger is simple in structure, good in sealing effect and small in machining difficulty of the curved surface of the downhole motor; the problem of poor metal sealing effect is effectively solved; and meanwhile, a modular structure is adopted, the multi-stage plunger structure can be installed for relay driving, the double-plunger structure is adopted to ensure that the internal force is balanced and stable, and the torque of the downhole motor is increased.

Description

technical field [0001] The invention relates to a power drilling tool, in particular to an all-metal downhole power drilling tool driven by high-temperature drilling fluid and based on a multi-stage double plunger-eccentric gear mechanism. Background technique [0002] It is an inevitable choice to use bottom hole power drilling tools to drive drilling and coring in high temperature and deep drilling fields such as deep earth drilling, high temperature geothermal, and ultra-deep wells. There are two basic types of downhole power drilling tools: screw drilling tools and turbo drilling tools. The all-metal turbodrill has the advantages of high temperature resistance and corrosion resistance. It is currently the only power drill that can drill in a high temperature and high pressure environment exceeding 250°C, but the turbodrill has high speed and low torque. As a positive displacement power drilling tool, the screw drilling tool has good mechanical output characteristics, bu...

AI Technical Summary

Problems solved by technology

As a positive displacement power drilling tool, the screw drilling tool has good mechanical output characteristics, but the rubber stator of the screw motor will fail quickly when the temperature exceeds 180°C, and cannot adapt to the long-term drilling operation under the high temperature condition at the bottom of the well.

The metal screw adopts a stator with an all-metal structure. The curved surface structure of the stator is difficult to process, easy to wear, and high in cost.

These power drilling tools have defects in temperature resistance, processing characteristics, output characteristics, etc., which seriously affect the mechanical efficiency and service life of power drilling tools

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