RU2803273C1 - Electric downhole motor for drilling oil and gas wels - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention is related to technical means for drilling oil and gas wells, ensuring the destruction of rocks in a mechanical way using an electric downhole motor (EDM). A device for drilling oil and gas wells, lowered on a drill string, contains an EDM, a rock cutting tool located under it and a battery storage unit located above it, a control system for turning on, off, and adjusting the EDM speed. To ensure power supply on the outer side of the housings of the battery storage unit and EDM either a cable with a hidden termination protected from damage by a protective overlay is laid, or power supply is carried out by means of an end current-conducting contact of the threaded connection of the battery storage unit and EDM. The end contacts are located at the end face of the shoulder of the threaded connection in such a way that when two threaded connections are twisted, said end contacts are in the same plane. To recharge the battery pack, an energy receiving system is located above it, which is a rectenna installed around the circumference along the outer and inner surfaces of the drill pipe, and the indicated EDM, the battery pack and the drill pipe with the rectenna are mechanically and electrically connected to each other in such a way that a cavity is formed.

EFFECT: increased reliability of the device.

3 cl, 7 dwg

Description

The invention relates to technical means for drilling oil and gas wells, ensuring the destruction of rocks mechanically using an electric downhole motor EDM (electric drill).

A device is known for supplying electricity to a downhole three-phase electric motor, carried out via a cable transmission line located inside the drill pipe, consisting of sections of a three-core hose cable with cable end couplings that are connected to each other when screwing up the drill pipes. However, such a power transmission line caused large hydraulic losses in the drill pipes and was structurally complex. To reduce hydraulic losses, an electric drill power system of the “two wires - drill pipes” type is used [F.N. Fomenko. Drilling wells with an electric drill. - M: Nedra, 1974. - P. 114-124].

The disadvantages of such a system are, in addition to the design complexity, the complexity of operation, since during the drilling process at various stages and operations it is necessary to control the parameters of the power transmission line.

An electric drill for drilling oil and gas wells is known, containing a bit for breaking rock, a spindle, a thrust bearing, an electric motor and a current lead that connects an energy source on the Earth's surface with an electric motor [RU 2321717 C1, IPC E21B 4/04, publ. 04/10/2008]. As a DC electric motor, it adopts a brushless DC motor with a thyristor switch. The control electrodes of the switch thyristors are connected to the output circuits of the rotor position sensor, which is powered by a high-frequency alternating voltage source. A high-frequency alternating voltage source is connected to the upper end of the current lead, and the lower end of the current lead is connected to the input circuit of the rotor position sensor through an electrical filter containing at least one electrical capacitor. In the second version, the input circuit of the rotor position sensor is connected to the lower end of the current supply through a voltage constant circuit.

The main trend of known technical proposals is to improve and refine the current supply system for power supply of an electric drill.

Common disadvantages of the described devices are the conductive system to the downhole electric drill and contact connections in the drill pipes. Another important factor limiting the use of electric drills in well construction is that all models in the power supply system do not have an equal in-line passage in the cavity of the drill pipes. This is due to the presence of a cable channel and a branded contact system connecting the pipes to each other, which makes it impossible to carry out a number of works, for example, eliminating sticking, installing a colmatation pack, carrying out geophysical research through the drill pipe down the well, and limits the use of the necessary equipment type equipment Yas, spiral blade calibrators in bottom hole assembly (BHA).

The above technical and technological limitations when using ECD in drilling wells served as a factor in their abandonment and the cessation of the development of this technical direction in the USSR and the Russian Federation.

There is a known section for the current supply to an electric drill, which includes a drill pipe with a coupling and a nipple and an internal pipe made of wear-resistant material placed in it with an annular gap, one end of which is fixed in the coupling using a sleeve, and the other in the nipple using a mandrel [RU 2660975 C1, IPC E21B 17/02, publ. 03.10.2017]. A cable is laid in the annular gap with conductive rings attached at the ends, which are mounted in the contact sleeve on the nipple side and in the contact tip on the coupling side, while the contact sleeve is inserted into the sleeve, and the contact tip into the mandrel. The cable is wound around the inner tube near the contact sleeve. When screwing together sections, the ends of adjacent internal pipes are pressed against each other to form a continuous hole inside them, suitable for pumping flushing fluid under pressure. Also, a torpedo or other equipment can be lowered along a continuous hole to eliminate sticking of the drill string.

The claimed technical solution is aimed at the development of domestic downhole drilling equipment for the construction of “highly intelligent” wells and the development of a promising direction for the construction of multifunctional wells for the extraction of “ready” energy resources such as hydrogen.

The technical problem, the solution of which is provided by using the invention, is to expand the functionality of electric downhole motors for drilling wells, by creating a design that makes it possible to use for drilling:

complex profiles of directional and horizontal wells with a fairly significant horizontal section of the well;

directional horizontal wells with a rising section of the profile along the productive part of the reservoir;

horizontal multilateral wells;

horizontal wells with low-frequency oscillators;

technological double-wellhead wells with one drilling point;

for drilling in tandem with a top drive system;

domestically produced mud pumps with low-power hydraulic parameters;

on depression during aeration of drilling fluid;

using standard emergency and drilling tools.

When implementing the invention, the problem is solved by achieving a technical result, which is to increase the reliability of the device by reducing in quantitative terms the contact connections in the drill pipes.

This technical result is achieved by the fact that a device for drilling oil and gas wells, lowered on a drill pipe string, contains a bit for rock destruction, an electric downhole DC motor and a current lead that connects the energy source to the electric downhole motor, and as an energy source A rechargeable battery pack is used, and additionally, rectennas installed on the outer and inner surfaces of the drill pipe are used as a means of recharging. In this case, an electric downhole motor, a battery pack, and a drill pipe with rectennas are connected to each other mechanically and electrically, forming an in-pipe hollow space.

An electric downhole DC motor (EDM) is connected via a threaded connection to the ABB (from one to the required amount in terms of power and energy consumption). It is possible to connect ABB to an electric drill using an electric cable running from ABB to the EDM along the outer casing of the EDM and protected from damage by a protective cover. It is also possible to connect the ABB to an electric drill using a system of end contacts, which are located at the end of the flange of the ESD and ABB threaded connection in the same plane when twisting two threaded connections, while the contacts are in close contact with each other in the threaded connection. For example, in known solutions with a well depth of 2000 m, the number of contact connections will be equal to 158, which significantly reduces the reliability of this electrical circuit. In turn, at any well depth there will be only one number of contact connections in the proposed solution. This ensures a high degree of reliability and also reduces the likelihood of failure. In this case, the performance check is carried out at the initial descent of the ECD and ABB, and does not require, as in the case of contact connections in drill pipes, constant testing during descent.

The difference between the proposed solution and the known ones is that the device for transmitting electrical energy from the wellhead to the electric drill located at the bottom, including the electrical cable channel and the system of electrical terminals, as well as the device for supplying electricity to the drill pipe (current collector), is replaced with a battery pack ( ABB). That is, the electric drill will be supplied with electricity in the downhole zone, which will reduce electricity losses, ensure a reliable supply of electricity, and reduce the time spent on assembling the drilling tool.

Due to the location of the ABB directly above the ECD, the pipe space on the lowered pipes and the BHA is uniform and equal-passing along the entire length from the wellhead to the bottom, which ensures the use of any composition of downhole tools in the BHA assembly, as well as the possibility of performing work on lowering geophysical instruments through the pipe space. The technical result obtained in this case allows the use of EDM with BHA assemblies of any range of downhole equipment and expands the scope of application.

EDM control, switching on and off, speed control can be carried out using known technologies, either from a pressure sensor or flow rate of the supplied drilling fluid, or using an automatic control system.

Charging of ABB on a drilling rig can be done both on the surface using a charger (classical method), and in a non-contact way at the bottom using a rectenna (a power receiving antenna consisting of an antenna and rectifier diodes that convert the energy of an electromagnetic wave into direct current) attached directly to ABB.

In turn, a rectenna can receive electrical energy in two ways: from the surface of the earth with a directed emitter located above the rectenna (for example, during horizontal drilling) or, for example, from the spark discharge energy of an Arkadyev-Baklin generator, or other, for example, microwave generators tuned to the frequency of receiving a rectenna lowered into the tubular space of a drilling tool to the level of the rectenna.

The essence of the invention is illustrated by illustrative materials.

In fig. Figure 1 schematically shows a device for drilling oil and gas wells, where the numbers indicate: 1 - rock-cutting tool (bit), 2 - electric downhole motor (EDM), 3 - battery pack (ABB), 4 - rectenna energy receiving system (AR) , 5 - layout of the bottom of the drill string (includes the calculated quantitative composition depending on geological conditions, drill collars, balanced UBTS, bladed spiral calibrator KLS, steel drill pipe SBT).

In fig. 2, section A-A according to Fig. 1, a rectenna energy receiving system is schematically shown, located around the circumference of the drill pipe outside and inside, where the numbers indicate: 8 - internal protective layer of the rectenna made of steel, in which (inside) the rectenna elements are located, 9 - internal rectenna elements (antennas and rectifier diodes ), 10 - drill pipe body, 11 - outer protective layer of glass-ceramic, in which (inside) there are rectenna elements, 12 - rectenna elements (antenna and rectifier diodes).

In fig. 3, callout B in Fig. 2, a system for receiving rectenna energy is presented, where the numbers indicate: 10 - drill pipe body, 13 - glass-ceramic layer in which (inside) the rectenna elements are located, 14 - rectenna elements (antenna and rectifier diodes), 15 - protective layer of the glass-ceramic antenna .

In fig. 4, callout C in FIG. 1, the power supply system from the battery pack to the electric downhole motor is schematically shown, where the numbers indicate: 2 - electric downhole motor, 3 - battery pack, 16 - sealed electrical connectors, 17 - electric cable, 18 - protective cover.

In fig. Figure 5 shows a section of the layout when charging the battery pack 2 using a spark gap through the internal rectenna 4, where the numbers indicate: 1 - bit, 2 - electric downhole motor, 3 - battery pack, 4 - rectenna energy receiving system, 5 - layout bottom of the drill string (includes the calculated quantitative composition depending on geological conditions, drill collars, balanced UBTS, bladed spiral calibrator KLS, steel drill pipe SBT), 6 - cable rope, 7 - protective capsule of the spark gap of the Arkadyev-Baklin generator .

In fig. Figure 6 shows a method for recharging the battery pack 2 during the construction of multilateral wells of the “Fishbone” type using an external rectenna 4 through a satellite well using HF or microwave energy, where the numbers indicate: 19 - multilateral well “Fishbone”, 20 - technological well (satellite well ), 21, 22, 23, 24, 25 - places of axial intersection of the satellite wellbore and the multilateral wellbore, located in the same vertical plane, but on different layers, 26, 27, 28, 29 - bottom of the wellbore.

In fig. Figure 7 shows the technological operation for recharging the battery pack 2 using a satellite well through an HF or microwave EMF generator unit, where the numbers indicate: 1 - bit, 2 - electric downhole motor, 3 - battery pack, 4 - rectenna energy receiving system, 5 - layout of the bottom of the drill string, 30 - drilling rig, 31 - generator of electromagnetic waves (EMW) high frequency (HF) and ultra high frequency (microwave) energy, 32 - cable for interblock connection (unit - EMW generator and modified flexible pipe string (MKGT)), 33 - unit for working with a string of flexible pipes, 20 - satellite well, 34 - MKGT waveguide type conductor, 35 - EMV compressor, 36 - antenna, 37 - formation, 38 - productive formation.

A device for drilling oil and gas wells (Fig. 1) contains a rock-cutting tool in the form of a bit 1, attached to it using a threaded connection (the size range is selected from the standards of threaded connections and is generally accepted for the corresponding diameter) of an electric downhole DC motor 2, providing rotation of the bit 1. A battery pack 3 is connected to the electric downhole motor 2 by means of a threaded connection, which is connected by means of a threaded connection to the body of the drill pipe 10 with a rectenna energy receiving system 4.

The arrangement of the bottom of the drill string 5 with the drill pipe 10 mounted on the body along the circumference outside and inside the rectenna 4 is mechanically and electrically connected to the battery pack 3 by means of a thread to ensure electrical insulation.

The power supply to the electric downhole motor is carried out through an electrical cable with a hidden seal running from the ABB to the EDM along the outer casing and protected from damage by a protective cover (Fig. 4), or through a system of end conductive contact of the threaded connection of the ABB and the EDM (end contacts located at the end the collar of a threaded connection, when twisting two threaded connections, the contacts are located in the same plane, tightly touching each other, and ensure the transmission of electricity).

The layout of the bottom of the drill string is assembled depending on the technological need when drilling wells. All assembly elements from the bit to the swivel or upper power drive are connected to each other by threaded connections in accordance with GOST. The design of a downhole electric motor uses a spindle, support bearings, an electric motor, and a battery pack connected to each other by a detachable connection. The system for turning on and off, as well as control (not shown) of the electric downhole motor 2 is carried out from an automatic control system according to the well-known principle of controlling the supply of drilling fluid, its volume and pressure, as well as the rotation speed of the torque on the bit. Such control is provided by the software system depending on the specified parameters of the well drilling interval, where the speed, bit rotation torque, and volume of supplied drilling fluid are selected. This system is integrated directly into the electric downhole motor.

A DC electric motor is used as an ECD. Lithium-ion types of batteries can be used as a battery pack. To manufacture a system for receiving rectenna energy on a drill pipe, for example, thin-film and thick-film technology for the manufacture of microcircuits and microboards can be used [Orlikov, L.N. Technology of materials and electronic products. Tomsk State University of Control Systems and Radioelectronics, 2012. - Part 1. - 98 p., Part 2. - 101 p.; Legostaev, N.S. Microelectronics. Tomsk State University, 2013. - 172 p.].

A device for drilling oil and gas wells operates as follows.

To destroy rock on a drilling rig (Fig. 1), the device layout is pre-assembled. As an example, the arrangement sequentially, from bottom to top, contains bit 1, sub (not shown), ESD 2, ABB 3, AR 4. The bottom hole assembly of BHA 5 includes drill collars, balanced UBTS, bladed spiral calibrator KLS, UBTS ( quantitative composition is supported by design loads), steel drill pipe SBT. The BHA is then lowered into the bottom hole, after which drilling fluid is supplied to remove the drilled rock, which in turn, reaching the EDM 2 and having collected the required pressure in the intra-pipe space from the control system (not shown in the figure), sends a signal to start the EDM 2 electric motor Next, the electric drill is set to the engine speed mode and drilling of the well begins. The rotation speed of the electric drill can be adjusted by increasing or decreasing the supply of drilling fluid through the electric drill control system. After completing the required drilling interval or at the end of the electrical energy in the ABB block 3, the device is removed from the well. The discharged ABB 3 unit is disconnected from the electric downhole motor and placed on charge.

When drilling, there are technological operations such as lifting a tool from a well, lifting a bit for the purpose of inspecting and testing weapons, and the like. For example, when drilling a vertical section of a well with BU-ZD86, where the depth is 3000 m, the time spent on lifting will be 6 hours, and from a depth of 5000 m, the time spent on lifting will be 11 hours. That is, it will take 12-22 hours to raise and lower a replacement ABB unit, while the charging speed will be much lower if you lift the assembly to a safe area and carry out accelerated charging. Also, by analogy, when constructing a Fishbone well, getting the assembly into the drilled hole can cause difficulties.

The charged ABB block 3 is attached to the electric downhole motor 2, then the entire assembly is assembled and drilling continues.

To recharge ABB 3 without lifting to the wellhead, the device includes an energy receiving system (recharging system) 4 - rectenna. Since the rectenna can be mounted in an arrangement both outside and inside the drill pipe, charging can be carried out in two ways: by lowering the charger into the intrapipe space or from the outside when using a satellite well. The rectenna design can receive a charge both when the charger is lowered inside the pipe (Fig. 5), and from an external device, that is, when the receiving antennas are located in the intrapipe space and on the outside of the drill pipe, then recharging can be done as follows.

The spark gap of the Arkadyev-Baklin generator or other sources of electromagnetic energy, such as a microwave generator, for the operation of which electricity is supplied from the wellhead to face along cable rope 6. During a spark discharge, the internal rectenna 8, 9 (Fig. 2 view A-A) receives the energy of the spark discharge and converts it into voltage (current) to charge the ABB 3 (Fig. 5). The spark gap 7 is lowered on the cable rope 6 (Fig. 5) for recharging for a short time, after which it is removed and the drilling work continues, the intra-pipe space is free again.

The recharging method with the possibility of using an external rectenna is relevant in the construction of multilateral wells of the “Fishbone” type, where recharging is carried out from the lowered antenna 36 into the process well (satellite well 20, Fig. 7). The production well is constructed according to the principle of spatial arrangement above or below the main Fishbone well, where the closest location of the two satellite wellbores and the Fishbone wells should intersect at the intersection of the Fishbone wellbores. This is necessary so that when recharging the ABB does not go out of the side barrel into the main barrel. That is, to recharge the ABB, they will remove the tool for advancing the ECD from the ABB to the point of intersection of the shafts, then stop and move the satellite along the well to points 26, 27, 28, 29 of the intersection of the shafts (Fig. 6) for recharging.

Recharging is carried out according to the following principle (Fig. 6, 7): from the unit - generator of electromagnetic waves of high and ultra-high frequencies 31, energy is supplied via cable 32 for interblock connection (unit - generator of electromagnetic waves and MKGT), then along the waveguide to the unit for working with the column flexible pipes 33, then along the waveguide MKGT 34 and transported along it to the device for storing EMV energy (EMV compressor) 35, where the energy of a continuous electromagnetic wave of high or ultra-high frequency is converted into the energy of HF or microwave pulses, the pulse power is an order of magnitude higher than the original power at the input of the EMW compressor, and is radiated through antennas 36 into formation 37. As a result of this impact, HF or microwave energy is received by the rectenna recharging system 4. The external rectenna (Fig. 2) receives HF and microwave energy, converts it into electric current and recharging ABB 3.

It is also possible to recharge the ABB using cable rope 6, lowered through the pipe space of the BHA with contact marks of the spark charger 7 for connecting and transmitting energy.

Thus, the claimed design of a device for drilling oil and gas wells ensures increased reliability due to the use of a battery pack (ABB) located directly in contact with the downhole electric motor of the device that supplies electricity with electricity. The capacitive capacity of ABB allows the required drilling interval to be worked out, after which it is removed from the well and replaced with a new one. The technical equipment of drilling rigs allows charging the battery pack on the drilling rig both on the surface using a charger (classical method), and in a non-contact way at the bottom using a rectenna (power receiving antenna) connected directly to the battery. Another important advantage of the device is the possibility of its use when drilling deep and ultra-deep wells with a large horizontal section, where the main value, when using downhole motors, is the drilling fluid flow rate in liters per second and the corresponding pressure to overcome the resistance of the liquid column, which is often not can be provided by domestic mud pumps, and when using the proposed device, such an indicator as the consumption of drilling fluid is not critical.

Claims (3)

1. A device for drilling oil and gas wells, lowered on a drill pipe string, characterized in that it contains an electric downhole motor, a rock-cutting tool located underneath it and a battery pack located above the electric downhole motor, a control system for turning on, off, and adjusting the speed of the electric downhole motor, and to ensure power supply on the outside of the housings of the battery pack and the electric downhole motor, either a cable with a hidden seal is laid, protected from damage by a protective cover, or the power supply is carried out through the end conductive contact of the threaded connection of the battery pack and the electric downhole motor, and the end the contacts are located at the end of the flange of the threaded connection in such a way that when twisting two threaded connections, these end contacts are in the same plane, while in order to recharge the battery pack, an energy receiving system is located above it, which is a rectenna installed in a circle on the outer and inner surface of the drill pipe, and the specified electric downhole motor, battery pack and drill pipe with rectenna are connected to each other mechanically and electrically in such a way that an in-pipe hollow space is formed. 2. A device for drilling oil and gas wells according to claim 1, characterized in that the rectenna located on the inner surface of the drill pipe is designed to be recharged from a spark gap or microwave generator lowered into the intrapipe space. 3. A device for drilling oil and gas wells according to claim 1, characterized in that the rectenna located on the outer side of the drill pipe is configured to receive energy to recharge the battery pack from the satellite well antenna, the trunk of which is located in the same plane with well under construction.

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