RU2443848C1 - Device for cleaning well bore from mud and elimination of differential wall sticking - Google Patents

Abstract

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to oil and gas industry and may be used in wellbore sweep and elimination of differential wall sticking. Device comprises drilling pipe, single-start welded or solid auger with 4-6 flights. Auger vane inclination to drilling string axial line makes 45-75°. Jet nozzles arranged at 45-75° to drilling pipe axial line to the left along auger direction are fitted in auger vanes on every lead of screw.

EFFECT: higher efficiency and clearing, expanded performances.

1 dwg

Description

The invention relates to techniques for drilling wells and is intended for flushing wells and eliminating sticking of the drill string when drilling for oil and gas, in particular when drilling a horizontal section and intervals of unstable rocks.

A device for cleaning the well of sludge or turbulator upward wash fluid (RU 2160818 C1, IPC7 E21B 21/00, publ. 04/19/1999). A device for cleaning a well from cuttings includes non-rotating drill pipes, a chisel, a downhole motor and centralizers with blades located at an acute angle to the axis of the drill pipes. The device is equipped with turbines installed behind the centralizers with the possibility of rotation around their longitudinal axes under the action of the flow of flushing fluid. The outer diameter of the turbine is less than the outer diameter of the centralizers. The direction of the centralizer blades along the direction of the wash fluid coincides with the direction of rotation of the bit.

The disadvantage of this device is the low efficiency due to the lack of additional turbulent flow and the likelihood of disruption of the natural filter cake during rotation of the layout elements and there is no anti-seizing effect, as well as the difficulty in replacing the elements of the device.

There is also known a device for removing drill cuttings from a horizontal section, taken as a prototype, which includes a drill pipe with a two-start and three-start screw with a pitch of 4.7 and 15 pipe diameters, the angle of inclination of the spiral to the centerline of 37 and 13 ° (abstract of I. Khabibullin A. Improving the processes of transportation of cuttings during the drilling of horizontal wells, Ufa; 2008, p.21-24).

A disadvantage of the known device is the low efficiency of cleaning the well from sludge, since when drilling inclined and horizontal sections of the wellbore a significant amount of drill cuttings accumulates, which gradually settles and fills the area of the lying wall, which often leads to sticking and jamming of the drilling tool in the well, and short life of the device.

Also a disadvantage of the above devices is the lack of the possibility of their use in the elimination of sticking of the drill string.

The task to which the claimed technical solution is directed is to develop a device for cleaning the wellbore from sludge and eliminating sticking of the drill string.

When implementing the claimed technical solution, the problem is solved by achieving a technical result, which consists in increasing the efficiency of drilling wells and improving the quality of cleaning the wellbore from sludge by expanding functionality, creating a turbulent flow, additional fluid flow rate.

The specified technical result is achieved by the fact that the device for cleaning the borehole from the sludge and eliminating the sticking of the drill string contains a drill pipe and a screw, which is used as a single-pass welded or continuous with a drill pipe screw with 4-6 turns, and the angle of inclination of the auger blades to the axial the line of the drill string is 45-75 °, and in the blades of the auger at each step of the turn there are hydraulic nozzles at an angle of 45-75 ° to the centerline of the drill pipe to the left in the direction of the auger.

The causal relationship between the claimed technical result and the essential features is as follows. Distinctive features are: the presence of a single-auger screw, in the blades of which are installed hydraulic nozzles that improve the removal of sludge, prevent the formation of an oil seal on the device in its auger part and sludge accumulation without rotation of the drill string and with rotation if necessary. The auger has sufficient strength to withstand the generated axial loads and torques when it is rotated to the right in the direction of the screw to eliminate the sticking of the drill string, which will allow the column to be moved down and thereby destroy the structure of the interval grasped by the rock. The claimed location of the nozzles increases the speed of the upward fluid flow and helps to remove the upper unstable layer of the borehole wall. Turbulent fluid flow in the well during drilling helps to prevent narrowing of the wellbore due to complete cleaning of the wellbore and a small gap between the auger of the device and the wall of the well. The device is also used to free the drill tool from sticking due to its rotation to the right in the direction of the screw. All tasks have been achieved.

The drawing shows a General view of a device for cleaning the borehole from sludge and eliminate sticking of the drill string.

A device for cleaning the wellbore from sludge and eliminating sticking of the drill string comprises a drill pipe 1 with a welded screw 2 or a pipe made jointly with a screw 2.

The screw 2 is a single-turn, the number of turns of which, for example, is from four to six, the width and height of the screw from the base of the drill string depends on the required degree of well cleaning, the fluid flow rate created in the interval of sludge sedimentation and the wavelength of the fluid flow after it passes through device. For example, the width is 30-35 mm and the height of the screw from the base of the drill pipe is 21-23 mm.

To create a turbulent flow, the required speed of the upward fluid flow and increase the strength characteristics of the device during the elimination of sticking of the drill string, the auger blades are located at an angle φ = 45-75 ° to the axial line AA of the drill pipe 1. A single-pass turn of the screw 2 is directed to the right along the entire drill pipes 1 from the coupling 3 to the nipple 4. In the blades of the screw 2 at each step of the turn are installed hydraulic nozzles 5 at an angle of 45-75 ° to the centerline of the drill pipe, to the left in the direction of the screw (directed along the blades along the move drilling fluid from the bottom to the mouth). The number and diameter of nozzles 5, in particular, 6-12 mm, are calculated based on the conditions for the removal of settling sludge from under the blades of the screw 2 and the prevention of the formation of oil seals in the groove between the blades of the screw 2.

A device for cleaning wells and eliminating sticking of the drill string works as follows.

During drilling, the drilling fluid in the well rises through the annulus from the bottom to the wellhead, where when the drilling fluid passes through the device for cleaning the borehole from the sludge and eliminates the sticking of the drill string, the drilling fluid enriched in the sludge passes through the screw 2, which the energy of the flow and creating additional hydraulic pressure between the turns of the screw 2 and the wall of the well begins to mix the drilling fluid, while spinning the flow, it gives it a rotational motion This prevents the settling of sludge in the well, and the installed hydromonitor nozzles 5 prevent the formation of glands between the turns of the screw 2 and the settling of sludge in the area of the lying wall of the device. After the drilling fluid passes through the device for cleaning the borehole from the sludge and eliminates the sticking of the drill string, the energy created by it and the flow rate continue to act for a certain distance, which helps to prevent sludge accumulation and narrowing of the borehole in the installation interval of the device. If there is a sticking of the drill string in the interval of the device, it is necessary to turn the drill string to the right and the stick will be eliminated.

The use of a device for cleaning the borehole from sludge and eliminating sticking of the drill string while drilling unstable, fractured and other rocks provides calibration and removal of drill cuttings from the zone of its subsidence. The proposed device can be implemented during the drilling of any wells, where the annular channel is slammed and the drill string is stuck, however, the most effective use for oil and gas drilling with a screw device is to use predominantly inclined and horizontal sections of the wellbore.

Claims (1)

A device for cleaning the borehole from the sludge and eliminating the sticking of the drill string containing a drill pipe and a screw, characterized in that the screw is a single-pass welded or continuous with a drill pipe screw with 4-6 turns, and the angle of inclination of the auger blades to the centerline of the drill the column is equal to 45-75 °, and in the blades of the screw at each step of the turn installed monitor nozzles at an angle of 45-75 ° to the centerline of the drill pipe to the left in the direction of the screw.