SU794181A1 - Borehole drilling method - Google Patents

Description

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The invention relates to the drilling of wells under difficult conditions and can be used in superdeep drilling, in drilling in strata with abnormally high formation pressures.

The well-known method of drilling wells, including the descent of concentric drill pipes to a certain depth, the injection of a gaseous agent into the additional annulus, which allows only part of the mud column to be aerated and the specific gravity of the 1J fluid to be regulated.

The disadvantage of this method is that when drilling wells with mud based solutions, the possibilities of aeration are limited. There is a sharp increase in squeezing pressure with increasing well depths. Circulation restoration in the presence of absorption zones is not always ensured. At the opening of productive layers, especially gas, the compressibility of the aerated liquid is good, which can greatly complicate the process of pressing the flowing well.

The aim of the invention is to increase the efficiency of the drilling process.

To achieve the goal in the method of drilling wells, including the creation of a circulating, flushing fluid in the drilling

pipes and annulus using pumping devices, create one or more modes of movement of flushing fluid with different characteristics by installing pumping devices in different parts of the drill string.

The method is reduced to the installation in the wellbore at certain depths of autonomous pumping devices, which, in the process of drilling the well, can pump out drilling mud (flushing fluid) from the well, or vice versa, inject it into it. Autonomous devices pump the fluid through the annulus, increasing or decreasing the velocity of the upstream flow.

The method is carried out as follows.

A drill string is lowered into the well with a bit or turbo-drill installed at the end. Further expansion of the drill string takes place after the installation of a submersible pump, which is driven by a submersible motor. During the drilling process, when the pump is in operation, the liquid is taken up through its lower windows and is pushed out through the upper holes located above the self-sealing packer. Pumping devices can be installed downhole at different depths.

When using the proposed method, the process of changing and maintaining the necessary pressure drop in the annulus and on the bottom is carried out quickly and without changing the specific weight of the drilling fluid. By creating the required value of the pressure drop per face, the maximum mechanical speed and penetration of the bit are achieved.

The capacity of the pumping devices can be adjusted from the surface. It is possible to dramatically increase the hydraulic power of a downhole motor.

By abruptly reducing the pressure drop in the annulus, it is possible to select fluids from productive formations directly during the drilling process.

Claims (1)

Invention Formula The method of drilling wells, including circulating the flushing fluid in the drill pipe and annulus using pumping devices, characterized in that, in order to increase the efficiency of the drilling process, one or more different characteristics of moving flushing fluid are created by setting the pumping devices to different parts of the drill pipe string. Sources of information taken into account in the examination 20 1. US Patent No. 3534822, cl. 175-69, published. 10.29.70.