RU2338064C1 - Method and device for contact-free data exchange and battery recharge of stand-alone logging devices - Google Patents

Abstract

FIELD: physics, measurement.

SUBSTANCE: invention concerns geophysics, particularly methods of contact-free data exchange between stand-alone geophysical logging devices and land reading device, and contact-free battery recharge for stand-alone geophysical logging devices. Stand-alone performance on land surface with closed lubricator is sustained due to inductance link to inductance coil wound on radiotransparent adapter under lubricator, and to inductance coil on charge and telemetry module with case of radiotransparent material. To achieve more efficient power transfer between coils a core is used. Well equipment with independent memory, suspended on wire, is brought down by hoist. Steel wire passes through sealed gaskets in upper lubricator part and through glass-fibre plastic adapter mounted between lubricator and wellhead assembly. When measurement cycle is finished, well equipment with stored data are brought up by hoist through wellhead assembly.

EFFECT: stand-alone operation of device.

7 cl, 5 dwg, 1 ex

Description

The invention relates to the field of geophysics, in particular to methods for contactless data exchange between autonomous logging geophysical instruments and a surface reader, as well as to the problem of contactless charging of batteries of autonomous logging geophysical instruments.

When carrying out logging operations in oil and gas wells, two methods of lowering measuring instruments into the well are usually used - on cable and on wire. In the first embodiment, a load-bearing geophysical cable is used, through which data is transmitted to the surface, and the power of downhole tools is also supplied. The advantage of this option is the ability to conduct continuous data transfer. The large diameter and mass of the insulated and reinforced cable create difficulties when lowering the instruments in high pressure wells. On the surface, such a cable is serviced by a self-propelled installation for cable (cable) work, which creates additional costs. In the second embodiment, downhole tools are lowered into the well on a smooth wire. In this case, the instruments must have autonomous power supply and memory blocks for temporary storage of geophysical information. The thickness of such a wire is usually equal to 1-2 mm, and its weight is tens of kilograms. Unlike a cable, a wire is easier to maintain and an ordinary light winch is used for lowering and lifting operations.

The main drawbacks in geophysical work on the logging cable are difficulties when lowering logging tools into high-pressure wells, as well as problems with well sealing associated with the large diameter of the cable. When working with smooth wire, both problems are eliminated, however, labor-intensive operations to safely remove devices from the well for further reading and charging batteries remain.

To work in production wells, a special sealing device is used, called a lubricator, which is installed above the fountain fittings. In the upper part, the lubricator has an oil seal for the tight passage of the logging cable, smooth wire or flexible pipes, depending on the operations performed. In the event of a high pressure drop, a sequence of gaskets designed for the required pressure is established. The lubricator device allows for the removal and hanging of logging tools without depressurization of the well. Before the logging tools are lowered into the well, the desired pressure is provided in the lubricator, and the opening of the valve allows the logging tools to be lowered using a winch.

Autonomous logging tools are equipped with devices for writing data to internal memory, and data is already read on the surface using a ground reader (or ground computer). To service such devices, as well as to read data and charge batteries, it is necessary to carry out the operation of disassembling the lubricator. This operation is quite laborious and is associated with the risk of spillage of the well fluid and oil. At the same time, each such operation takes quite a lot of working time and requires the presence of highly qualified personnel.

In the practice of cable and boring operations, methods for exchanging information between geophysical instruments and well elements are known. Several inventions (US 5971072, US 3534310) describe inductive devices in a well completion tool and self-contained inductive transmitters installed at specific locations in the drill string. When such an instrument approaches an autonomous transmitter, information is exchanged and certain operations are performed. This can be the operation of stopping and securing the tool, the operation of initiating the perforation charge and other operations of completing the well.

Also known are methods of wireless inductive coupling between a bunch of instruments in a well and a surface reader (patent application US 20060244628). In this technical solution, the wire on which the logging tools are lowered is used as an antenna for transmitting real-time data. The lower and upper ends of the wire are equipped with inductive couplers. Data from downhole tools is fed to a data transmission device connected to a lower coupler. A multimeter wire for launching downhole tools actually works as a long antenna for transmitting frequency-modulated data. However, the disadvantage of the system is that in the case of strong attenuation of the high-frequency information signal in the antenna, it is necessary to use radio frequency repeaters installed along the entire length of the wire. The use of such repeaters allows maintaining the power of the information signal at the desired level. However, the placement and maintenance of radio frequency repeaters on the wire significantly complicates the operation of lowering and lifting downhole tools.

The closest technical solution is the method proposed in patent EP 0678880, for the implementation of which they use a device for measuring pressure and temperature directly in the well, made in such a way that it can be repaired and restored without stopping the well. This device is lowered into the well on flexible pipes and coaxially mounted on an inductive system permanently mounted in a mandrel for a removable valve during gas-lift operations. Then the flexible pipes are removed from the well, and the device remains in the mandrel. The cable connected to the inductive system is led through the annulus to the surface; the cable is used to power the device and read the measured data in real time. However, the presence of a power cable and binding to a ground reading system does not allow the device to be used in hard-to-reach places requiring autonomy.

The technical result of the claimed invention is the creation of a stand-alone device for contactless data exchange and a method for charging batteries of autonomous downhole geophysical instruments through inductive coupling. A significant advantage of the proposed technical solution is the autonomy of the device, as well as the fact that the necessary operations are performed on the surface with a closed lubricator. Inductive coupling is made between an inductor wound on a radiotransparent adapter under a lubricator and an inductor in a charge and telemetry module, the casing of which is made of radiotransparent material. A core is used to provide more efficient energy transfer between the coils.

The invention is presented in figure 1, figure 2, figure 3 and figure 4.

Figure 1 shows the General diagram of the descent of downhole tools on a smooth wire and the location of the radio-transparent adapter on the wellhead equipment. According to Figure 1, downhole tools 1 with autonomous memory are suspended on wire 2 and are moved using a winch. Steel wire passes through sealed glands (not shown) in the upper part of the lubricator 4. After the measurement cycle is completed, downhole tools with recorded data rise to the surface with a winch through the wellhead 5. An adapter 3 made of fiberglass is installed between the lubricator 4 and the wellhead.

Figure 2 shows a longitudinal section of a radiotransparent adapter at the time of maximum approximation of the internal and external inductors, where 12 is the core, 13 is the external inductor, 14 is the inductor making up the induction system 20, 17 is the charge and telemetry module, 19 is the external reader device.

When passing a bunch of downhole tools through a radiotransparent adapter, in particular when lifting devices to the surface, an external low-voltage voltage is applied to the outer inductor 13 wound on the inner surface of the radiotransparent adapter 3. The current from the winding 13 is measured by an external reader 19. In the upper part of the bundle of downhole tools, a charge and telemetry module 17 is installed, through which data is exchanged between the downhole tools and the external reader 19.

When approaching the charge module and telemetry 17, having an inductor 14 and a core 12, to the radiolucent adapter 3, the current in the winding 13 increases due to the amplification of the inductive coupling between the windings. The maximum current on the inductor 13 is an indicator for stopping the winch and the beginning of data exchange and battery charge. The combination of the inner winding 14, the outer winding 13 and the core 12 will hereinafter be described as an induction system 20. Through inductive coupling, a data reading command is sent to the telemetry module 17, after which the telemetry module begins to transmit data from the downhole tools through the inductor 14 to the inductance coil 13 and further to the external unit 19 and the PC ground computer.

For the manufacture of radiotransparent adapter 3 and the housing of the telemetry module 17 should be used sufficiently strong material, designed for hydrostatic pressure inside the wellhead equipment, and also having low absorption of radio waves in the range of 50-100000 Hz. The radio transparency of the walls of the adapter 3 and the housing of the telemetry module 17 makes it possible to exchange data and charge batteries with minimal energy loss. The most suitable material for implementing this invention is fiberglass with high mechanical strength and low losses in the specified frequency range. Other radiolucent materials (composites or ceramics) lose fiberglass in terms of mechanical strength and manufacturability, but can still be used to implement the invention. The length of the radiotransparent adapter 16 is selected 1.5-2 times greater than the length of the inductive system 20, in order to reduce the loss of the inductive signal at the terminal conductive elements of the adapter. The inner diameter of the radiotransparent adapter 16 is chosen equal to the inner diameter of the downstream wellhead equipment, so as not to create difficulties when moving downhole tools.

The general diagram of an external reader 19 is shown in FIG. 3. In this drawing, the inductor 24 is part of the induction system 20 through which the battery is charged and the data are exchanged with the downhole tool. The energy source for charging batteries is an industrial 220 V network with a frequency of 50 Hz. Data is exchanged at a high frequency relative to the low frequency of the industrial mains. The low-frequency battery charge current and the high-frequency information signal are mixed in a mixer made on transformer 23. Winding I of transformer 23 is used to connect an industrial network, winding II is used to connect the transceiver 21 of the ground unit and winding III is used to connect the primary (external) induction winding systems 20. In order to protect the transceiver from voltage coming from the charging winding I to the transceiver II winding, an overvoltage protection module is used eniya 22. The transceiver 21 is connected to the input of a personal computer PC, where the storage and processing of data read from the downhole device (devices).

As a transceiver modem, it is possible to use standard frequency modulated modems (FSK), for example, the widespread CMX469 manufactured by CML Microcircuits Ltd, USA. When using such modems, the maximum exchange rate with the downhole tool is 4800 bits per second, which is quite enough for most applications. At the same time, the operating frequency range at the modem output is from 2400 to 4800 Hz, which makes it easy to isolate a high-frequency information signal against a background of a charging current of 50 Hz using simple first-order filters. To increase the exchange rate, it is possible to use more advanced FX929 modems (up to 9600 bps) manufactured by CML Microcircuits Ltd or standard Manchester code encoders / decoders, for example, 588ВГ6 manufactured by Integral, Belarus or HD6408 made by Intersil, USA. In the latter case, the encoder-decoder for the Manchester code allows you to organize communication channels with an exchange rate of up to 1 Mbps, and the throughput of the communication channel is limited only by the properties of the transformer 23 and inductive system 20 with winding 24.

The block diagram of the charge module and telemetry 17 is presented in Fig.4. A low-frequency voltage of the battery charge is induced on the winding I of the induction system 20, which is rectified in the rectifier unit 32 and then converted to a constant voltage on the capacitor unit 33. The charger 34 directly controls the process of charging the batteries 35. The transceiver winding II of the induction system 20 is connected to the block telemetry 36, which is performed similarly to blocks 21 and 22 of the ground module.

An example implementation of the present invention.

To assess the efficiency of the proposed method, a test setup was used (Figure 5). A secondary winding 14 (2000 turns of PETV-1 0.25 mm wire) was wound onto a core 12 made of ferrite grade 1000НН (size 10 × 100) and a fiberglass cloth was wound on top until the outer diameter of the winding was 28 mm (assumed to be the outer diameter of the downhole tools). The primary winding 13 is wound on a hollow fiberglass cylinder with an inner diameter of 50 mm (chosen equal to the inner diameter of the fountain fittings). The type of wire and the number of turns are taken to be the same as in the secondary winding. Both windings are immersed in a beaker 40 filled with an aqueous solution of sodium chloride with a concentration of 50 g / liter (simulated formation water). The primary winding 13 through an isolation transformer 42 (transformation ratio 1: 1) is connected to an adjustable autotransformer 41 type LATR-2.5. The secondary winding 14 is loaded on a resistor 47 (resistance 100 Ohm, power 5 W). The voltage and current on the primary winding 13 are controlled by a voltmeter 43 and an ammeter 44. Similarly, the voltage and current on the secondary winding 14 are controlled by a voltmeter 45 and an ammeter 46. The voltage applied to the primary winding of the inductive system 20. The position of the autotransformer controller 41 changes. This voltage is selected in this way to prevent core saturation 12.

The efficiency was estimated by the formula η = ((V2 · I2) / (V1 · I1)) · 100%, where V2 and I2 are the readings of the voltmeter 45 and ammeter 46 in the secondary winding 14, V1 and I1 are the readings of the voltmeter 43 and the ammeter 44 v primary winding 13. In this test setup, an efficiency of about 20% was obtained, and the dissipated power at resistor 47 was about 2 watts, which is enough to charge the batteries in downhole tools in an acceptable amount of time. Preliminary calculations show that by optimizing the design and material of the core 12, by optimizing the number of turns and the diameter of the wire of the windings, an increase in efficiency of up to 50% is possible even when operating in oil-in-water mixtures with a higher salt concentration. Such optimization will increase the power transmitted to the secondary winding and, therefore, reduce the battery charge time.

Claims (7)

1. A method for contactless data exchange and battery charge of autonomous logging tools, according to which downhole tools with autonomous memory are suspended on a wire with the possibility of movement using a winch inside and outside the well, so that the wire passes sequentially through a lubricator, a translucent adapter and wellhead equipment, in the upper part of the bundle of downhole tools, a charge and telemetry module is installed, a charge and telemetry module is moved inside the radiolucent adapter, and tvlyayut communication between downhole devices and the external reading device, and carry a charge auxiliary batteries logging tool. 2. The method according to claim 1, where through inductive coupling to the telemetry module, a data reading command is sent, after which the telemetry module begins to transmit data from downhole tools to an external unit and a ground computer. 3. The method according to claim 1, where the radiotransparent adapter is made of fiberglass. 4. The method according to claim 1, where the radiotransparent adapter is chosen 1.5-2.0 times longer than the length of the inductive system. 5. The device for contactless data exchange and battery charge of an autonomous logging tool, which is a radio-transparent adapter located on the wire above the logging tool bundle, and a charge and telemetry module located on the wire in the upper part of the logging tool bundle with the possibility of the module passing through the radiolucent adapter the movement of the module, where the outer winding of the inductor connected to an external reader, and the charge and telemetry module consists of a winding of an inductor and a core located inside the inductor so that the outer winding of the inductor, the winding of the inductor and the core are an induction system. 6. The device according to claim 5, where the inductor is part of the induction system through which the battery is charged and data is exchanged with the downhole tool, and the low-frequency battery charge and high-frequency information signal are mixed in a mixer made on a transformer, winding I which is connected to the industrial network, winding II is connected to the transceiver of the ground unit through an overvoltage protection module, winding III is connected to an external winding and an induction system, the transceiver being connected to the input of a personal computer that stores and processes data read from downhole tools. 7. The device according to claim 5, where the charge and telemetry module includes rechargeable batteries connected to the capacitor block through a charger connected through the rectifier unit to the winding of the inductance coil of the induction system, and the transceiver winding of the second inductor of the induction system is connected to the telemetry block.

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