RU2520976C2 - Oil and gas well repair unit and method for running coil tubing in and out by means of this unit - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: group of inventions is related to oil industry and intended for workover, geophysical and thermal and hydrodynamic surveys of oil, gas and other wells using coil tubing and for well intervention. The unit (Fig. 1) includes a transportation basis 1 with two outriggers 12, the operator's cabin with control system 9, a drum 2 with drive 4, coil tubing 3, a winder 10 for winding of coil tubing to the drum, an injector with jigging blocks 5 with a guider 11 installed before it, the injector drive 6, sealing and BOP equipment 7 connected to the well Christmas tree 8 and a logging module 14, at that the drum drive is a power drive unit, the guider is made as a roll, coil tubing (Fig. 2) is a polymer-coated steel tubing; at the unit there is an installed pump 13 and a speed sensor measuring speed of the tubing feed to the well, two delivery force sensors and a metre measuring length of the tubing in the well, at that the above sensors, a temperature sensor and a well-pressure gage, the third delivery force sensor, a gamma-activity indicator, an accelerometer, a collar locator and the metre measuring length of the tubing in the well are connected to the control system, at that the logging module includes a temperature sensor and a well-pressure gage, a collar locator, a gamma-activity indicator, an accelerometer and the third delivery force sensor.

EFFECT: provision of workover, geophysical and thermal and hydrodynamic surveys of oil, gas and other wells.

5 cl, 1 ex, 2 dwg

Description

The group of inventions relates to the field of the oil industry and is intended for underground repair, geophysical and thermohydrodynamic studies of oil, gas and other vertical wells, deviated wells and wells with horizontal sections of the profile using a flexible pipe and for performing downhole operations - washing, removing hydrate and paraffin plugs , perforation and other works.

In modern technology, a well installation for servicing oil wells is known, comprising a vehicle with guide beams, a drum with a continuous steel pipe, a feed mechanism (this mechanism is called an injector, wellhead feeder, conveyor or feed device) with four hydraulic stands arranged in pairs, of which the opposite in relation to the well, a pair of hydraulic struts is rigidly connected to the base of the feed mechanism and is equipped with rollers for extension along the guide beams to the working position, and the extension of the feed mechanism to the working position. To increase productivity by accelerating and simplifying the installation and alignment of the feed mechanism at the well and expanding technological capabilities, the pair of hydraulic struts facing the well is connected to the base of the feed mechanism pivotally, and the pair of hydraulic struts opposite to the well is equipped with support shoes for placing rollers in them, the extension unit of the feed mechanism to the working position is made in the form of two hydraulic cylinders and ropes with flip rollers, the ends of the rope being connected to the support shoes of hydraulic racks, and the middle of the rope - with a feed mechanism through the hydraulic cylinder, the drum is made in the form of two concentric shells, an outer one with holes and an inner one, forming an annular cavity for supplying heated air to it (SU 1439197 A1, E21B 19/22, E21B 19 / 00, 11/23/1988).

The disadvantage of this design is the low durability of a continuous steel pipe, due to the double bending cycle of the pipe during its descent and removal from the well. The first pipe bending cycle takes place when it is unwound from the drum - the pipe straightens from a bent position. The second bending cycle is at the entrance to the injector, where the pipe from a rectilinear form is repeatedly bent before entering the injector. In addition, the relative position of the operator’s cab, drum and injector eliminates the simultaneous monitoring of their functioning.

The closest analogue is an underground well repair unit using a flexible steel pipe, containing a transport base, on the frame of which there is a control cabin, transmission, a drum for winding a flexible pipe, an injector providing for forced movement of the flexible pipe, mechanisms for transferring the injector and control cabin to the working position mouth sealant. The axis of rotation of the drum for winding a flexible pipe is parallel to the axis of the transport base, which, when the unit is in working position, passes through the axis of the well (RU 2154146 C2, E21B 19/22, 10.08.2000).

The disadvantages of this unit are the fragility of the flexible pipe, the complexity and high cost of construction. The use of steel pipe has a number of negative consequences. When passing through the injector and when winding onto a drum, the steel pipe is subjected to irreversible plastic deformation, when immersed in a well under high pressure in contact with oxygen, it is subject to accelerated corrosion, and due to high fatigue due to cyclic stresses, the flexible pipe is cracked and quickly destroyed and eventually becomes unusable.

The use of a steel pipe also makes it difficult to design due to the additional introduction of a guiding device in it in the form of an arc before the pipe enters the injector. The use of this device is necessary in order to increase the radius of bending of the steel pipe and thereby reduce the deformation of steel and increase its service life.

Since steel is a heavy material, this forces the use of expensive high-power injectors.

The disadvantages of the prototype also include the uneven distribution of the load on the flexible pipe during the hoisting operations, due to the fact that the main traction component of the structure is the injector, and the drum is intended only for winding the pipe and its storage. In this case, when lifting and lowering the pipe into the well to a greater depth, a tensile force is applied to the pipe section located below the injector, much greater than the pipe section between the drum and the injector. This leads to accelerated destruction of the pipe, and also forces the use of expensive high-power injectors.

The objective of the proposed group of inventions is to simplify and cheapen the design, increase the service life of the flexible pipe.

This problem is solved due to the fact that the unit for repairing oil and gas wells contains a transport base with two outriggers located at the rear of the transport base, an operator's cab with a control system located in front of the transport base, a drum with a drive located in the middle part transport base, a flexible pipe, a flexible pipe stacker on a drum, an injector with pressure pads, in front of which there is a guide device, an injector drive, a sealing and blowout preventer udovanie, which is connected to the fountain fittings of the well installed above the wellhead, and the logging and technological module mounted on the lower end of the flexible pipe and having a cable communication channel with the control system, while the drum drive is made power, the guiding device is a roller, a flexible pipe It is a steel-polymer pipe, a pump is installed on the unit for supplying a pulsating pressure to the pipe cavity, as well as a sensor for measuring the pipe feed rate into the well, two force sensors dachas, one of which is installed on the stacker and the other on the injector, and a pipe length meter in the well, the above sensors, a temperature sensor and a pressure sensor in the well, a third pipe supply force sensor, a gamma activity indicator, an accelerometer, a coupling locator and the pipe length meter in the well is connected to the control system, while the logging-technological module includes a temperature sensor and a pressure sensor in the well, a coupler locator, a gamma activity indicator, an accelerometer and a third pipe feed force sensor .

The steel-polymer pipe may consist of a pipe body made of a thermoplastic polymer, for example, polyethylene, polypropylene, polystyrene, polycarbonate, polyvinyl chloride and so on, transverse reinforcement made of steel tape of rectangular cross-section, laid at an angle of 45-60 degrees to the axis of the pipe, and longitudinal steel wire reinforcement.

A method of lowering and raising a flexible pipe using an oil and gas well repair unit includes feeding it into the well using an injector, further immersing the pipe into the well under its own weight, lifting the pipe and uniformly winding it onto the drum using a stacker, while feeding the pipe in the well, the drum operates in a braking mode, after the start of immersion of the pipe into the well under its own weight, the injector and the drum simultaneously operate in a braking mode, while the process is controlled by those installed on the unit a speed measuring sensor, a pipe feed sensor into the well, two pressure transmitting force sensors, one of which is installed on the stacker, and the other on the injector, and a pipe length meter in the well, providing by comparing their readings with the readings of the logging module installed at the lower end of the pipe, monitoring the progress of the pipe end and detecting its forced stops during advancement, while pulsating pressure is applied to the pipe cavity using the pump to overcome forced stops, at the next lift of the pipe, the lifting force is distributed between the injector and the drum, and the winding force created by the drum is set by an algorithm that includes the control system calculating the force required to lift the pipe from the well, setting the drum drive for each pipe layer on the drum to pull the pipe to prevent crushing of the pipe, moreover, the aforementioned force is controlled by means of a force sensor mounted on the stacker in such a way that if the pulling force has reached an allowable maximum, then the sensor The IR sends a signal to the control system, which, in turn, sends a signal to the drum drive to reduce the force, while the drive force of the injector is ensured by the fact that the control system subtracts from the required total tractive effort the force created by the drum drive and sends the received signal to the injector drive, when the end of the pipe exits the well to prevent its ejection due to wellhead pressure, sealing and anti-blowout equipment are installed at the exit from the well and, cr IU addition, when extracting the tube retains its injector. For each stage of pipe descent or ascent into the well, the control system can set the force of pressing the injector blocks against the flexible pipe, which provides static friction between the pipe and the blocks, sufficient to ensure the movement of the pipe together with the blocks and preventing the pipe from slipping.

EFFECT: replacement of a guide device in the form of an arc by a roller, replacement of a powerful injector with a low-power one, reduction of pipe fatigue and its deformation under the influence of cyclic stresses, reduction of injector wear and elimination of corrosion processes on the pipe surface.

Due to the fact that the flexible pipe is made of thermoplastic polymer and steel, it is cheaper, much less susceptible to irreversible plastic deformation, when immersed in a well under high pressure in contact with oxygen, it does not undergo accelerated corrosion and has less corrosion than steel pipe fatigue when exposed to cyclic stresses.

The use of a steel-polymer pipe makes it possible to simplify the design by replacing the guide device in the form of an arc with a roller, and also allows the use of less powerful injectors.

The use of a drum equipped with a power drive, which during the lifting operations along with the injector takes on the main load, also allows you to use a cheap low-power injector and eliminates the accelerated destruction of the flexible pipe due to the uneven distribution of load on it during operations.

The control system controls the force of pressing the injector clamping blocks against the flexible pipe, depending on the required feed force or injector braking force, providing optimal loading of the parts and components of the injector and, therefore, reduces its wear.

Figure 1 shows a diagram of a unit for the repair of oil and gas wells, and figure 2 shows a flexible steel-polymer pipe.

The unit is arranged as follows. In the front of the transport base 1, which is supported on the ground by two outriggers 12 located in the rear of the transport base, an operator's cab with a control system 9 is installed, and a drum 2 with a drive 4 is installed in the middle part. For smooth laying of a flexible steel-polymer pipe 3, the lower end of which a logging and technological module 14 is installed, a stacker 10 is used on the drum when winding. A pump 13 is used to supply pressure to the flexible pipe.

At the rear of the unit is a roller 11, designed to guide a flexible pipe in front of the injector (wellhead feeder) 5, equipped with a drive 6. Sealing and blow-out equipment 7 is located below the injector, which is connected to the fountain fittings of the well 8 located above the wellhead.

Fountain reinforcement is a set of devices mounted at the wellhead for its sealing, suspension of elevator pipes used to raise formation fluids - oil, gas, water, to the surface during development, fountain and gas lift operation of wells and control of production flow of the well.

A flexible steel-polymer pipe may consist of a pipe body 15 made of a thermoplastic polymer, in particular polyethylene, transverse reinforcement 16 made of steel tape of rectangular cross-section, laid at an angle of 45-60 degrees to the axis of the pipe, and longitudinal reinforcement 17 made of steel wire. If the angle between the axis of the pipe and the steel tape is less than 45 degrees, then in places where the pipe bends, the tape will become very bent. If this angle is more than 60 degrees, this will lead to a strong stretching of the pipe in the case when its weight in the well is of great importance.

In addition to the elements shown in the drawing, electrical cables can be integrated into the pipe body. In this case, the pipe is called a umbilical.

The unit can operate in two modes - lowering and lifting a flexible pipe. The mode is set in the operator's cab with the control system 9. The descent of the flexible pipe into the well is as follows. The flexible pipe is fed into the well, including into the well with wellhead pressure, by means of an injector 5, while the drum 2 operates in a braking mode and thereby provides the pipe to the injector with preliminary tension.

When in the future the pipe reaches a sufficient depth to sink into the well under its own weight, the injector and the drum begin to synchronously operate in a braking mode. This process is controlled due to the fact that the unit has a sensor for measuring the feed rate of the pipe into the well, two sensors for the force of its supply, one of which is installed on the stacker, and the other on the injector, and a pipe length meter in the well (not shown in the drawings) providing by comparing their readings with the readings of the sensors of the logging and technological module, monitoring the progress of the end of the pipe and the detection of forced pipe stops during its movement, due to:

- friction forces arising in places of well curvature;

- overcoming the paraffin or asphaltene plugs available in the well.

To overcome the places of forced stops using the pump 13, a pulsating pressure is supplied into the pipe cavity.

At the end of the pipe, a logging-technological module 14 is installed with the following elements:

- temperature and pressure sensors in the well, which eliminates the use of the pipe in conditions that exceed the temperature and pressure limits for it;

- a locator of couplings designed to track the movement of the end of the pipe in the well and accurately set it to the required depth by determining the location of the coupling and locking joints;

- an indicator of gamma activity, ensuring the binding of the end of the pipe to the section of the well;

- an accelerometer that controls the acceleration of the end of the pipe along the wellbore, including in places where the wellbore is curved and its horizontal part;

- a force sensor that controls the feed force of the end of the pipe during its descent and its tension if a load is placed at the end of the pipe.

The subsequent rise of the flexible pipe from the well is as follows. The lifting force is distributed between the injector 5 and the drum 2, and the winding force generated by the drum is provided according to the winding algorithm specified by the control system located in the operator’s cabin 9, eliminating crushing of the pipe on different layers, and the force created by the injector takes this value so that the sum of the efforts of the drum and injector is sufficient to ensure the extraction of the pipe from the well.

The winding algorithm and the traction force generated by the drum and injector drives are specified as follows. At the beginning, the control system calculates the force required to lift the pipe from the well. For each layer of pipe on the drum, the control system sets the drum drive to a corresponding pulling force to prevent crushing of the pipe, the aforementioned force being monitored by a force sensor mounted on the stacker. If the pulling force has reached the maximum permissible value, the sensor sends a signal to the control system, which, in turn, sends a signal to the drum drive to reduce the force. Then the control system subtracts from the required total force the force that is generated by the drum drive and sends the received signal to the injector drive.

To exclude the ejection of the pipe under the action of wellhead pressure when removing the end of the pipe from the well, sealing and anti-blowout equipment 7 is installed at the exit from the well and, in addition, the injector holds it when removing the pipe.

The control system provides control of the pressing force of the injector clamping blocks against the flexible pipe, depending on the required feed force or injector braking force, which ensures optimal loading of parts and components of the injector and increase its durability.

This is achieved as follows. For each stage of pipe descent or ascent into the well, the control system sets the value of the force N _{F of the thrust of} pressing the injector blocks against the flexible pipe so that between the pipe and the blocks a _static friction force is provided with a certain margin, "sufficient to ensure the movement of the pipe together with the blocks, and it does not happen pipe slippage: This value is automatically calculated by the control system using the following formula:

$$N_{Ft\mathrm{I\; am}g\mathrm{and}}=\left({\displaystyle \underset{O}{\overset{n}{\int }}d{F}_{t\mathrm{I\; am}g\mathrm{and}}}/K_{tR}\right)\cdot \mathrm{1.25,}$$

where: F _traction - traction force of the injector;

To _tr - reduced coefficient of friction of a thermoplastic polymer on steel blocks;

O <n <max; max - maximum traction force of the injector (in the case when the pipe is completely immersed in the well);

1.25 - safety factor.

Uniform winding of the pipe on the drum provides stacker 10.

Claims (5)

1. A unit for repairing oil and gas wells, comprising a transport base with two outriggers located at the rear of the transport base, an operator's cab with a control system located at the front of the transport base, a drum with a drive located in the middle of the transport base, a flexible pipe , a flexible pipe stacker on a drum, an injector with pressure pads, in front of which there is a guide device, an injector drive, sealing and blow-out equipment that is connected to the fountain by the well reinforcement installed above the wellhead, and the logging and technological module installed on the lower end of the flexible pipe and having a cable communication channel with a control system, characterized in that the drum drive is made power, the guiding device is a roller, the flexible pipe is a steel-polymer pipe, a pump is installed on the unit for supplying pulsating pressure to the pipe cavity, as well as a sensor for measuring the pipe feed rate into the well, two sensors for its supply force, one of which is set it is new on the stacker, and the other on the injector, and a pipe length meter in the well, the above sensors, a temperature sensor and a pressure sensor in the well, a third pipe supply force sensor, a gamma activity indicator, an accelerometer, a coupler locator and a pipe length meter in the well connected to the control system, while the logging-technological module includes a temperature sensor and a pressure sensor in the well, a coupler locator, a gamma activity indicator, an accelerometer and a third pipe feed force sensor. 2. The unit according to claim 1, characterized in that the steel-polymer pipe consists of a pipe body made of thermoplastic polymer with transverse reinforcement made of rectangular steel tape laid at an angle of 45-60 degrees to the pipe axis, and longitudinal reinforcement made of steel wire. 3. The unit according to claim 2, characterized in that the body of the steel-polymer pipe is made of polyethylene. 4. A method of lowering and raising a flexible pipe using an oil and gas well repair unit, including supplying it to a well using an injector, further immersing the pipe into the well under its own weight, lifting the pipe and winding it onto the drum using a stacker, characterized in that when the pipe is fed into the well, the drum operates in a braking mode, after the pipe has been immersed in the well under its own weight, the injector and the drum simultaneously operate in a braking mode, while the process is controlled by the speed sensor a spindle, a sensor for supplying the pipe into the well, two sensors for the force of its supply, one of which is installed on the stacker, and the other on the injector, and a pipe length meter in the well, providing by comparing their readings with the readings of the sensors of the logging-technological module installed on the bottom the end of the pipe, monitoring the progress of the end of the pipe and detecting its forced stops during advancement, while to overcome the forced stops, a pulsating pressure is applied to the pipe cavity using the pump, with the subsequent lifting of so that the lifting force is distributed between the injector and the drum, and the winding force created by the drum is set by an algorithm that includes the control system calculating the force required to lift the pipe from the well, setting the drum drive for each pipe layer on the drum to pull the tube to prevent crushing of the pipe, and the above the force is controlled by means of a force sensor installed on the stacker in such a way that if the pulling force has reached the permissible maximum, then the sensor gives a signal to the system control, which, in turn, sends a signal to the drum drive to reduce the force, while the drive force of the injector is ensured by the fact that the control system subtracts from the required total tractive effort the force created by the drum drive and sends the received signal to the injector drive, when the end of the pipe exits the well in order to prevent its ejection due to wellhead pressure, sealing equipment and blow-out equipment are installed at the well exit and, in addition, when removed and pipe it keeps the injector. 5. The method according to claim 4, characterized in that for each step of lowering or raising the pipe into the well, the control system sets the force of pressing the injector blocks against the flexible pipe, which provides rest friction between the pipe and the blocks, sufficient to ensure the movement of the pipe together with the blocks and excluding slippage of the pipe.

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