RU49879U1 - FLOATING DRILL PIPE - Google Patents

Abstract

The invention relates to the drilling of tunnel shafts with a diameter of up to 1400 mm for laying oil and gas product pipelines, communication lines, power transmission lines, etc. A floating drill pipe includes locking connecting elements associated with a tubular body. An air annular cavity is made in the wall of the pipe body along its entire length. EFFECT: light weight of the drill string to relieve harmful loads during operation.

Description

The invention relates to the drilling of tunnel shafts with a diameter of up to 1400 mm for laying oil and gas product pipelines, communication lines, power lines, etc.

The floating pipe is designed to transmit torque from the drilling rig to the bit or reamer with which the wells are drilled, to supply flushing fluid from the pump to the bottom of the hole, and to create a load on the bit or reamer to destroy the rock while drilling the well. All of these issues are performed by the drill pipe string.

With the current state of engineering and technology for drilling, many types of wells are drilled for oil, gas and water.

Wells are vertical, directional and vertical, and with the transition to horizontal. The technology is currently being developed and wells are drilled with a diameter of 300-1400 mm under obstacles with the wellbore entering the rock to the obstacle, drilling under the obstacle and with the wellbore reaching the surface behind the obstacle, the well length is up to several thousand meters. Such trunks are drilled for laying oil and gas pipelines, power lines and communications under rivers, highways and railways, lakes and other natural and artificial barriers.

In all cases, vertical, inclined, including horizontal inclined shafts were drilled while drilling the initial “Pilot” trunk under obstacles, “from one’s own”, ie away from the rig. The load on the rock cutting tool-chisel in vertical and directional wells is made due to the weight of the estimated number of weighted drill pipes (UBT) and partial discharge to the bottom of the weight of the drill string. When drilling a “Pilot” well under obstacles, the drill string is sent to the bottom and the load on the bit is created by the drilling rig, as the entire drill string in this case lies on the wall in the inclined and horizontal parts of the trunk.

The weight of the column in this case does not work on the table wiring, but creates additional, significant harmful loads on the drilling rig from friction forces on the borehole walls and forces of alternating bending load during rotation. When drilling under obstacles, the drill string is in particularly difficult, unusual conditions compared to vertical and inclined shafts. In this case, the drill string connecting the bit with the drilling machine drive mechanisms mounted on the surface of the earth is a kind of long drive shaft with very limited transverse dimensions, operating without intermediate supports. This shaft transmits significant power required by the bit or reamer.

for the effective destruction of drilled rocks, spent on overcoming significant resistance forces from the friction of the column in the liquid on the wall of the well. In this case, the shaft is in a difficult stress state from the action of tensile, compressive and bending loads created during rotation in a fairly spatial wellbore and having a significant dead weight. From twisting the drill string into the spring due to its large weight and friction forces in the borehole of a large diameter with its subsequent reversal of the shocks, it creates the effect of unfastening the threads of the tool joints. After unfastening the thread of the tool joint, the thread is broken and the drill string is disconnected. After unfastening the thread of the locking joint in a horizontal trunk of large diameter, reconnecting to no avail, you have to drill the trunk again.

From the patent literature known drill pipe with gas lining see US Pat. RF №02149975 IPC E 21 V 17/00 publ. 06/11/1997, bull. Number 23. The invention addresses the special issues of drilling vertical exploratory, producing oil, gas and special wells for scientific purposes. A drill pipe device is proposed that includes a supporting tubular body equipped with lock joints with a coating placed on its surface in the form of an annular float element with a density lower than the density of the fluid filling the well. The float element is made in the form of a vessel of small diameter, filled with helium. The invention does not address the purpose of facilitating a drill pipe in a fluid. Equipping the coarse float element is technologically difficult and expensive. The float elements are not protected in terms of strength against hydraulic shock of the pumped liquid, especially in conditions of extremely low or high temperatures of the atmosphere or ultra-deep wells. There is no guaranteed service life of float elements, especially when working with acids and alkalis used in well drilling. In the case of leakage of lightening gas from depressurized containers, drill pipes become heavier and their rise from an ultra-deep well will become impossible, because tensile stresses on the metal of the pipe will become outrageous.

The closest in technical essence and the achieved result to the claimed technical solution is a drill pipe protected by RF patent No. 2015293 IPC E 21 V 17/00 bull. No. 12, 1994. The invention addresses the issue of facilitating drill pipes in flushing fluid while drilling various types of exploratory, producing oil and gas wells, but this technical solution does not address the issues of drilling inclined and horizontal boreholes of large diameter up to 1400 mm. The drill pipe contains a housing with connecting locking elements and annular float elements located in the cavity of the housing. For laying siphons, oil and gas pipelines, power transmission lines and communications, the authors of the patent offer

the manufacture and placement of the lightening element is rough in plastic or aluminum containers, which do not work under the conditions of pumping acids and alkalis. Fluid through drill pipes, when drilling all types of wellbores, is pumped only by double and single acting piston pumps. Pressure pulsation and water hammer when working with piston pumps are inevitable. Containers with lightening material or float elements, as stated in the description of the invention, are in a pulsating fluid pressure environment with hydraulic shocks up to 200-250 atmospheres, without the necessary strength, they will necessarily deform towards a decrease in volume with increasing pressure and water hammer. Cracks will appear in the shells of containers and in the lightest material in the first hours of operation. The fluid that is pumped through the pipes penetrates the facilitating elements and their specific gravity is equal to the specific gravity of the flushing fluid. As a result, the drill pipe lightening effect will disappear. The high cost of these pipes will be unjustified.

The present invention eliminates the disadvantages of the prototype and performs the task of lightening the weight of the drill string to relieve harmful loads. This is achieved through the development and creation of floating or significantly facilitated drill pipes in the flushing fluid due to the buoyancy effect, according to Newton's law. Reducing the weight of the drill pipe will allow the installation of intermediate support-centralizers, which will bring the rotating column closer to the centerline of the well. The approach of the column to the axis of the borehole will reduce alternating bending loads along the pipe body and in threaded joints. The load on the rotary and feed mechanism of the drilling rig will be reduced by reducing the weight of the column and friction forces.

Drilling of the same shafts will require a drilling rig of lesser power, the problems associated with the liquidation of accidents and the costs of wiring wellbores as a whole will decrease. It will be possible to drill longer trunks.

The problem is solved using the features specified in the claims common to the prototype, such as a floating drill pipe, including tool joints connected to the tubular body and distinctive essential features, such as an air annular cavity made in the wall of the body rough along its entire length. The above signs provide:

1. Reducing the cost of power to overcome the forces of the phenium of the pipe body on the rock component of the well wall.

2. Reducing the magnitude of the torque to drive the rock cutting tool into rotation of the bit or reamer used for drilling the well.

3. Reducing the tensile forces exerted by the drilling rig on the drill string when creating a load on the bit or reamer,

destructive rocks.

4. Decrease in alternating tensile, twisting and bending loads in a large diameter well.

5. The ability to install intermediate supports under the drill string to reduce stress and prevent twisting of the drill string, consisting of these pipes, into the spring, which eliminates its breakage and eliminates the accident rate from pipe breakage in wells of a similar design.

The invention is illustrated in the drawing, which shows a pipe including locking connecting elements: a locking sleeve 1 and a locking nipple 2 connected with a tubular body 3. In the pipe body 3, an air annular cavity 4 is made along its entire length, bounded by an inner 5 and an outer 6 wall connected to locking elements 1 and 2 by a weld seam inner 7 and outer 8. The tubular body 3 has a passage channel 9 for liquid.

A drill string for drilling boreholes under various obstacles is assembled from individual drill pipes. The creation in the wall of the pipe body along its entire length of an air annular cavity, the immersion of which in the liquid creates a buoyancy force, and which will facilitate the total weight of the pipe and the drill string as a whole. The authors called this pipe "floating". To connect the pipes to each other, at the ends of each pipe, a lock thread 10 is cut. At one end, the lock thread is a female thread and the lock thread is zinc at the other end. After assembling all the parts by welding, a drill pipe with an air annular cavity 4 and a passage channel 9 is obtained.

Calculation of the drill pipe, the required size, for buoyancy in the flushing fluid.

1. Outer pipe:

Outer diameter Dnar = 177.8 mm

Wall thickness - δ = 6.9 mm.

Weight of 1 running meter, taking into account the weight of couplings 29.1 kg. on the metro

2. Inner pipe NKT-2 "Dp. 60.3 mm.

δ = 5 mm. Weight of 1 running meter, taking into account the weight of the couplings 6.93 kg.

3. The volume of displaced fluid will be

R is the radius of the outer pipe Dnar: 2 = 88, 9 mm. L = 10 decimeters.

V = L × π × (Dnar: 2) ²

V = 10 × 3.14 × 88.9 ² = 10 × 2.4816-24.816 l. at 1 pm

4. The buoyancy in the clay solution is γ = 1.14 kg / dm. Will be torn. = V × γ = 24.816 × 1.14 = 28.290 kg. per 1 running meter.

5. The total weight of the floating drill pipe in the air will be:

G = G ₁ + C 2 + G _water ; Where

G ₁ - weight 1 linear meter of external pipe 29.1 kg per 1 linear meter Meter

g ₂ - weight 1 linear meter of tubing 2 "= 6.93 kg. per 1 running meter. Internal volume 2" of the pipe 2 liters per 1 lm, provided that it is filled with water, the weight inside the water pipe G will be 2 kg. at 1 pm 6. Total weight of floating rough

G = G ₁ + G ₂ + G _water = 29.1 + 6.93 + 2 = 38.03 kg. Per 1 l.m

Given the buoyancy force, the weight of one linear meter of a "floating" pipe in a solution will be:

Gmelt. = G-Tear. = 38.03-28.29 9.74 kg. at 1 pm

A 139.7 mm drill pipe, which bores are drilled under obstacles, has a weight of one running meter of 32.6 kg or 35.6 kg. Thus, the decrease in the weight of the drill string in a horizontal well will be: 35.6 kg -9.74 kg = 25.86 kg per linear meter.

The table shows a comparison of the weights of the columns of conventional pipes and "floating".

According to the invention, the floating drill string is made double-walled. The pipe walls, both internal and external, are made of the same steel grade as conventional drill pipes. The wall thickness is calculated and provides for operation in hydrodynamic conditions without the risk of destruction.

Pipe tensile and torsional strength are calculated and does not differ from pipes required for drilling these wells.

The effect of floating rough while drilling inclined and horizontal boreholes of large diameter wells will remain until the end of operation, i.e. to the maximum permissible wear of the wall thickness and threaded joints, which is natural for all types of drill pipes.

The structural strength, reliability of operation, ease of manufacture and low cost of a floating pipe are not comparable with all analogues of previous inventions. Tests of the rough proposed design showed positive results.

Table Column Length Drill stand. 139.7 mm.kg Pipe 177.8 mm, kg. Floating. TOTAL 100 3560 974 200 7120 1978 27% STANDARD PIPES 300 10680 2922 139.7 mm. 400 14240 3896 500 17800 4870 1 35.6 kg 1 lm 9.74 kg 1 lm

Claims (1)

A floating drill pipe including tool joints connected to the tubular body, characterized in that an annular air cavity is made in the wall of the pipe body along its entire length.