SU1701883A1 - Method of hole construction in gragmental inundated incoherent rocks - Google Patents

Abstract

The invention relates to the mining industry, in particular to methods for the construction of wells. The purpose of the invention is to increase the economic efficiency of the method. The wellbore is drilled under the conductor, the conductor is installed, followed by cementation. After that, the transition to the drilling of the main and near-hole parts of the wellbore with a smaller diameter to the design depth is made. The wellbore part of the wellbore is drilled with a diameter equal to or less than 0.5 of the diameter of the main part of the wellbore, not exceeding the triple diameter of the latter. The drilling tool is then removed, the jig is covered with a cap and the well is left for later use for hydrogeological purposes. 1 il. (Ls

Description

The invention relates to the mining industry, in particular to methods for the construction of wells.

There is a known method for constructing wells in detrital watered uncemented rocks, including drilling for the conductor, installation of the conductor, ztsebnuyu cementation, drilling of a smaller diameter to the design depth, expansion of the trunk to sizes exceeding twice the diameter of the trunk, at a height from the bottom not exceeding three times the diameter of the trunk .

The disadvantage of this method is its complexity, which consists in the need to use the extender.

The aim of the invention is to increase the economic efficiency of the method.

The goal is achieved by those. that a method of constructing wells in detrital watered uncemented rocks, including drilling a wellbore under the conductor, installing a conductor with its subsequent cementing, drilling the main part of the wellbore and drilling the bottomhole part with a diameter at the boundary of the main and bottomhole part of the trunk more than twice the diameter of the bottom, and the height from the border to the bottom, not exceeding the tripled diameter of the main trunk, the bottom hole part is made in the form of a trunk with a diameter less than 1/2 the diameter of the main trunk ola

The drawing shows a well constructed according to the proposed method, a vertical section.

Xi

About 00

with

Oj

In the drawing indicated; 1 - conductor; 2 - cement ring; 3 - the main part of the wellbore diameter D; 4 - surface before drilling; 5 - bottom-hole part of a borehole with diameter d and length I;

6- surface before drilling with diameter do;

7- boundary between the main and bottomhole parts of the barrel; 8 - separation crack; 9 - conductor cap; 10 - weld; 11 - slaughter.

The method is carried out as follows.

Drilling with a large diameter with the installation of the conductor 1 and the cement ring 2. Drill a smaller diameter main part 3 of the barrel, then go to the drilling of the bottom hole part 5 of the trunk in compliance with dependencies: d 0.5D; I 3D. Upon completion of drilling of the bottom-hole part 5 of the borehole with the bottom 11, a cover 9 is installed on the welding 10, and the well is preserved. At the boundary of the bottomhole part 5 of the borehole with the bottom 11 d do, which causes cleavage stress and formation of the cleavage crack 8, which, having reached the boundary 7 between the main and bottomhole parts of the trunk, stops the further development of the Ring wedge-shaped layer of detrital rocks bounded by surfaces 5, 7 and 8, then collapses and slides down. At the same time, the main part of the trunk remains in a stable state. During the re-entry, the cover 10 is removed, the production string is lowered into the wellbore and the necessary complex of works on development and testing is carried out in it.

The wells, drilled using mud as a flushing fluid, are equipped with large holes after degreasing, and clean water is equipped with mesh filters.

Example. The implementation of the method for the rotational drilling method using pure water as a washing liquid,

Drilling under the conductor 1 with a length of 4-6 m is carried out using mud.

After installing the conductor 1 and the cement ring 2, go to drilling the main part 3 of the barrel using clean water, maintaining the water level in the barrel 1.52, 0 m above the static level. Then move on to drilling the bottom-hole part 5, observing the dependencies; d, 5; I D. Upon completion of drilling, install cover 9 on welding 10, preserving the well. After that in

left on the preservation of the well pr 61-, the sliding of the layer bounded by surfaces 5, 7, and 8 proceeds. After the re-preservation, the filter column with a mesh filter is lowered into the main part of the barrel, maintaining the water level by 1.5-2.0 m above static. After installation of the filter column, in-tube washing is performed to clean the surface of the filtration openings from

sand and clay particles and water repellency. Then go to pumping and pumping.

The invention makes it possible to switch on a mass scale without any special additional costs to the use for hydrogeological purposes of wells drilled in detrital watered uncemented rocks by a rotational method for geological exploration, geotechnical engineering, etc. that do not require casing of the main part of the wellbore.

Claims (1)

Invention Formula A method of constructing wells in detrital, watered, non-cemented rocks, including drilling the wellbore under the conductor, installing the conductor with its subsequent cementation and further drilling of the main and bottomhole parts of the wellbore to the design depth, characterized in that, in order to increase economic efficiency, the bottomhole part of the wellbore is drilled with a diameter equal to or less than 0.5 of the diameter of the main part of the borehole; exceeds three times the diameter of the well. in 1