Hydraulic auxiliary piston pressurized bottom hole reverse circulation fishing tool

Abstract

The invention discloses a hydraulically assisted piston pressurized bottom hole reverse circulation fishing tool, which comprises a hydraulic device installed in the upper cavity of a pressurized nipple, a pressurized nipple and a flow channel sequentially connected from top to bottom Conversion sub, slider and overshot; booster sub consists of a booster sub body with a cylindrical structure and a worm and worm gear rotation mechanism, transmission mechanism and Piston mechanism; the flow channel conversion nipple includes a nipple body and a one-way valve; the slider is composed of a slider nipple and balls randomly inlaid on the outer wall of the slider nipple; There are multiple openings at the top opening of the body that can be opened upwards; this tool can shorten the circulation process, reduce energy loss, ensure that the fishing tool can be lowered to the predetermined position in a well with a large inclination angle, and provide enough falling objects Or debris storage space, improve construction efficiency.

Description

technical field [0001] The invention relates to the technical field of downhole operation of oil and gas wells, in particular to a hydraulic auxiliary piston pressurized bottom hole reverse circulation fishing tool. Background technique [0002] When carrying out litter or debris salvage operations in oil, gas and water wells, the litter at the bottom of the well is washed or salvaged to the ground mainly by means of full wellbore positive circulation or reverse circulation. The full wellbore positive circulation method means that the bottom of the tubing string is brought down to the bottom of the well with a pen tip, and the surface pump is used to inject the workover fluid from the tubing at high pressure and large displacement, and the debris or debris is washed at the bottom of the well to make it impact the bottom of the well, and the tubing and the annulus between the casing and return to the surface. If the falling objects at the bottom of the well are large, it is ...

AI Technical Summary

Problems solved by technology

Especially in the salvage operation of oil, gas and water wells with large inclination angles (such as high-inclination wells, horizontal wells, etc.), affected by the wellbore trajectory, the hydraulic loss of the workover fluid during the circulation process is serious, resulting in Insufficient hydraulic energy to achieve salvage operations

However, increasing the pump pressure and displacement on the ground will not only increase the cost of equipment, energy and workover fluid volume, but also make the surface pipelines bear higher pressure, increase the risk of puncture leakage, and pose a safety hazard

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