Method for well drilling and cementing of radial horizontal well with ultra-short radius and equipment thereof

Abstract

The invention relates to a method for well drilling and cementing of a radial horizontal well with ultra-short radius and equipment thereof. A method of well drilling before well cementing is adopted and the method comprises the steps of: well drilling: universal joints are used to connect a plurality of flexible drill stems, a first-section flexible drill stem and an angle gain drilling head, an angle gain device is installed in a vertical well hole, and the upper surface of the device is a steering curved face inclined downwards; the flexible drill stems are made inclination on the steering curved face of the angle gain device, and the device is taken out of the well after well drilling; well cementing: a plurality of sections of flexible sleeves connected by hinged extension pipes are placed into the well hole for well cementing. Meanwhile, the minimum outside diameter of the angle gain drilling head is not less than that of the flexible drill stem, and the outside diameter of the flexible drill stem is not less than that of the flexible sleeve. The invention has the advantages that: the damage to sleeves is reduced; flexible sleeves are put in position for well cementing after well drilling, and therefore the strength of flexible sleeves is approximate to that of common sleeves; well drilling can not be affected even if small eccentricity occurs in the process of well drilling, and flexible drill stems can arch in reverse direction to avoid barriers when rubbing against well walls.

Description

technical field [0001] The invention relates to the field of oil and coal bed gas exploitation, in particular to a drilling method and equipment for an ultra-short-radius radial horizontal well. The ultra-short-radius radial horizontal well drilling can be realized by using the tool. Background technique [0002] In the petroleum and coalbed methane industry, the ultra-short-radius sidetracking technology, which simultaneously exploits multiple formations in the same well, is one of the main means of increasing production in the late stage of petroleum exploitation. [0003] Oil wells are divided into long-radius wells, medium-radius wells, short-radius wells and ultra-short-radius wells according to the radius of curvature. A well with a curvature radius greater than 500 meters is a long-radius well, a radius of curvature between 100 and 500 meters is a medium-radius well, a radius of curvature between 20 and 100 meters is a short-radius well, and a radius of curvature less...

AI Technical Summary

Problems solved by technology

[0014] The technical problem to be solved by the present invention is to provide a drilling and cementing method for ultra-short-radius radial horizontal wells, so as to solve the defect that the flexible drill pipes with slotted and bent pipes in the prior art cannot go down well smoothly. Ultra-short radius sidetracking horizontal well with curvature radius less than 2m

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