Radial horizontal well sealing device, drilling equipment and drilling method

Abstract

The invention provides a radial horizontal well sealing device, drilling equipment and a drilling method, and relates to the technical field of geological drilling equipment. The radial horizontal well sealing device comprises a sealing shell, an injection pipe, a sealing element, a power feeding mechanism and a rotary drilling mechanism; the sealing element is of an active rolling type dynamic sealing structure and is arranged between the sealing shell and the injection pipe; the rotary drilling mechanism and the power feeding mechanism both adopt high-pressure jet fluid as a power source so as to transmit rotary power and feeding power to the injection pipe; and the drilling equipment comprises an oil pipe, a steering gear, a jet drill bit and a sealing device. By virtue of the sealing device, static friction sealing is changed into dynamic friction sealing, passive sealing is changed into active sealing, and the sealing device has the advantages of reducing drilling cost, being long in service life of equipment, high in drilling efficiency and the like, is also suitable for high-temperature and high-pressure stratums and can avoid the problem that traditional static friction sealing fails.

Description

technical field [0001] The invention relates to the technical field of geological drilling equipment, in particular to a radial horizontal well sealing device, drilling equipment and a drilling method. Background technique [0002] As the development of oil and gas fields enters the middle and late stages, most of the remaining oil reservoirs are low permeability, heavy oil, thin oil layers and fractured oil and gas reservoirs. Radial horizontal wells, full name ultra-short radius radial horizontal wells, also known as ultra-short radius horizontal wells. , Lower crude oil extraction cost has become the leading technology of crude oil extraction in the world. Radial horizontal well technology includes two processes of casing window opening and bottom drilling. The principle is to use the window opening drill bit to open holes in the casing of the oil layer, and then use the hydraulic jet action of high-pressure jets and the rotary crushing action of small drill bits to brea...

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Problems solved by technology

[0010] At present, the traditional radial well sealing structure uses a rubber seal at the joint between the oil pipe and the steering gear. When the oil pipe is pressed down, the seal between the rubber seal and the steering gear is a sliding static seal structure. The parts are prone to fatigue and wear problems, and the spikes on the injection pipe are easy to pierce the rubber, resulting in sealing failure. Because the sealing performance of the radial well tubing has become the main indicator of its completion degree, poor sealing performance will lead to high-pressure fluid leakage. The hydraulic pressure is reduced and the formation cannot be broken; moreover, fluid sealing and power feeding are a contradiction. In the existing radial horizontal well tubing sealing device, if the sealing is too tight, the tubing activity will be reduced, or even locked. can't guarantee

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