RU2537452C1 - Procedure for well swabbing by viscous fluid and device for its implementation - Google Patents

Abstract

FIELD: oil-and-gas industry.

SUBSTANCE: method of well swabbing by viscous fluid includes stages where: swab if preliminary run to the viscous fluid border with preset temperature 40°C minimum and 100°C maximum; swab is submersed under the viscous fluid level with preset speed 0.3m/s minimum and 1m/s maximum; power is directly supplied to the swab from surface equipment using the geophysical cable, then the power is supplied through the cable lug by means of the electric energy channel to the swab lower part; electric energy by means of the converter installed in the lower part of the swab is converted to the thermal electric energy and is transmitted under the viscous fluid level ensuring its local heating to temperature of the fluid liquefaction with simultaneous swab run; at that run speed and well fluid temperature are monitored during the entire swab run; in case of deviation of the swab run speed and temperature from the preset values the electric energy quantity supplied from the surface is changed; the viscous fluid sampling and lifting to surface are performed using the swab.

EFFECT: improved efficiency of development of high viscous oil or bitumen well by means of swabbing.

17 cl, 1 dwg

Description

The invention relates to the field of the oil industry, in particular to the development of oil or bitumen deposits, development and repair of wells, namely to swab wells with viscous fluid using heat.

The claimed invention can also be used to achieve various goals, including the challenge of inflow from the formation during well development, cleaning the bottomhole zone of reaction products after chemical treatment, cleaning the bottom of mechanical impurities carried out from the bottomhole zone of the formation (if it is impossible to wash the bottom due to the absorption of the flushing solution due to the good permeability of the bottom-hole zone or low reservoir pressure), cleaning the bottom-hole zone of mechanical impurities introduced by the injection agent st, bottomhole treatment by physical methods of stimulation.

There is a method of developing a reservoir of viscous oil or bitumen (RF patent No. 2305762, IPC E21B 43/24, publ. Http://www.fips.ru/cdfi/fips.dll?ty=29&docid=2305762&cl=9&path=http:// 195.208.85.248/Archive/PAT/2007FULL/2007.09.10/DOC/RUNWC1/000/000/002/305/762/document.pdf "\ o" Official publication in PDF format "\ t" _blank), including continuous drilling horizontal well with the placement of the inlet section of the well before the productive formation, conventionally horizontal section of the well along the strike of the productive layer, upward section with an inclination from the reservoir to the surface, casing installation columns, cementing the annulus, installing tubing with centralizers, pumping coolant and selecting viscous oil or bitumen, specify the distribution of productive thicknesses of the reservoir over the area of the reservoir, drill at least one pair of continuous horizontal wells, the horizontal sections of which are placed parallel to one another in a vertical plane at a distance that prevents premature breakthrough of condensate to the production well, casing strings with a filter are installed in the interval the reservoir, cementing the annular space of the columns is carried out to the top of the reservoir, the coolant is pumped through the upper horizontal injection well from the wellhead and bottom hole, at the same time, viscous oil or bitumen is taken through the lower horizontal production well from the wellhead and bottom hole using a swab.

A known method of producing highly viscous oil (RF patent No. 2206728, IPC E21B 43/24, publ. 06/20/2003), including the descent into the casing string of the tubing to the perforation interval, the flow of coolant along it, the rise of the product through the annulus the casing string is lowered by two tubing strings, the first being lowered to the beginning, and the second through the first to the end of the perforation interval and coolant is supplied through it, and gas is supplied to the space between the casing and the first tubing string they are taken in the space between the tubing strings, after ensuring the given injectivity, the production is stopped, the coolant pumping is continued to the calculated value, while the gas supply is continued, the space between the tubing strings is filled with it and maintained in this state, then the well is stopped thermocapillary impregnation before the onset of an intensive decrease in fluid mobility in the near-wellbore zone, the pressure in the well is depressurized, the product entering it is selected to decrease The flow rate obtained in the natural regime of the formation, the cycle of pumping the coolant and product selection is repeated until a zone with a moving fluid is created with the producing well, after which the well is transferred to the injection, and the production is taken through the production well.

Known self-heating balancing load (patent CN No. 200989190 (Y), IPC E21B 36/04, E21B 43/00, publ. 2007-12-12) containing a nose outlet, a protective shell, a switch, a control element, many nickel-hydrogen batteries , a high-performance heater and a shell in which the nasal outlet is connected to a swab, a protective shell seals and protects parts of an autothermal balancer, a switch controls the operating state of a high-efficiency heater, a control element delays the connection of the circuit and protects the charge and discharge of many nickel-hydrogen batteries that provide energy for conversion to heat, a highly efficient heater converts electricity to heat, the shell is made with the possibility of protection and heat transfer.

A device for dredging crude oil is known (CN patent No. 2588050 (Y), IPC E21B 43/00, publ. 2003-11-26), closest in technical essence to the claimed device and adopted as a prototype containing an electric generator, a frequency conversion control cabinet , a winch with double wheels, a power cable and a swab for oil production with an electromagnetic heater, while one end of the power cable is connected to the frequency conversion control cabinet, and the other end is connected to an electromagnetic heater, the heater is located at corresponding to the fluid level in the well, and power is turned on for preheating. After that, the heater rises, the power turns off, and the tool for oil production is placed in the liquid, and thus, the heated crude oil is produced in the well.

The objective of the invention is to provide a method and development of a device to improve efficiency, the possibility of development (production) of wells containing highly viscous oil or bitumen by swabbing.

The design of the device allows to reduce the accident rate (cable or device breakage), increase the efficiency of the process of extracting liquid by swabbing, and reduce energy consumption.

The technical result, the achievement of which the claimed invention is directed, is to increase the efficiency of development of wells containing highly viscous oils or bitumen by swabbing.

The technical result is achieved by the fact that the method of swabbing a well with a viscous fluid includes the steps of: first lowering the swab device to the border with the viscous fluid, immersing it under the level of the viscous fluid, supplying electrical energy directly from the ground equipment using a geophysical cable to the swab device, which is then fed through the cable lug through the channel of electric energy to the lower part of the swab device, is converted using izhney portion svabiruyuschego device electric power converter in thermal electric energy into heat and transfer it to the level of the viscous fluid, carrying his local heating to liquefy the temperature of the downhole fluid while lowering svabiruyuschego device selects a viscous fluid and rise to the surface using svabiruyuschego device.

Local heating is carried out in continuous or intermittent mode throughout the descent of the swab device.

Immerse the swab device under the level of viscous fluid at a predetermined speed.

When the immersion rate of the swab device deviates from the pre-set level of the viscous fluid from the predetermined level, the amount of electric energy supplied from the surface is controlled.

The immersion speed is set equal to at least 0.3 m / s and not more than 1 m / s.

Regulate the speed of immersion of the swab device in a viscous fluid by weighting it.

Immerse the swab device under the level of viscous fluid under its own weight.

Control the swab device from the surface.

Receive telemetric information about the well from the swab device, conduct its analysis, based on the results of which adjust the control swab device from the surface.

From the obtained telemetric information about the well, the temperature of the well fluid is determined, and when the temperature of the well fluid deviates from a predetermined temperature, the amount of electric energy supplied from the surface is controlled.

The pre-set temperature is at least 40 ° C and not more than 100 ° C.

The technical result is also achieved by the fact that in the device for implementing the method comprising a swab device connected to ground equipment, it is new that the swab device comprises a cable lug in its upper part that provides mechanical and electrical connection with a geophysical cable connected to ground equipment , and in its lower part contains a converter of electrical energy into heat, connected to a cable lug through an electric energy channel gii.

The cable lug provides mechanical and electrical connection to the electrical energy channel.

The converter of electrical energy into thermal energy is surrounded by a protective shell having direct contact with the internal environment of the well and configured to transfer thermal energy to the well.

The protective shell is made of metal.

Swabbing device is streamlined elongated and with the possibility of changing mass and length.

The mass of the converter of electrical energy into heat is at least 30 kg.

The length of the converter of electrical energy into heat is not less than 0.5 meters and not more than 1.5 meters.

The swabbing device further comprises at least one temperature sensor.

The electric energy channel and the geophysical cable are configured to transmit telemetry information from at least one temperature sensor to ground equipment.

Ground-based equipment contains a telemetry information analysis and swab control device.

The converter of electrical energy into thermal energy is made using a heating element (thermoelectric heating), or electrochemical heating, or with the possibility of induction conversion of electrical energy into thermal energy.

The swabbing device further comprises an overheat protection unit.

The essence of the method is as follows.

Swabbing device is lowered to the border with a highly viscous medium and it begins to smoothly immerse it under the level of a highly viscous medium (hydrostatic level of the well fluid).

Electric energy is supplied from the well surface to the swab device, which is then converted into thermal energy and transferred to the internal environment of the well, i.e. begin to locally heat the borehole fluid surrounding the lower part of the swab device.

Swabbing device begin to lower under the level of a viscous medium under its own weight or at a certain predetermined speed. In case of deviation of the immersion speed from the set, the amount of supplied electric energy is regulated: when the speed is slowed down, the amount of supplied electric energy is increased, and when increased, it is reduced.

Bring the temperature of the supplied heat energy to the temperature of the fluidization of the well fluid. The current temperature of the well fluid is determined by telemetry information received from a swab device. Depending on the type of well fluid, the dilution temperature can range from 40 ° C to 100 ° C. If the liquefaction temperature is exceeded, they reduce the amount of supplied electric energy, otherwise they increase it.

Depending on the goal, local heating can be carried out in different modes: in continuous or intermittent mode, and is carried out throughout the descent of the swabbing device.

Upon completion of the passage of a given path with a swab device, one-time selection and lifting of a highly viscous fluid by swabbing is performed.

If necessary, all steps can be repeated until the required injectivity of the well is achieved or until a predetermined volume of high-viscosity fluid is obtained.

The descent of the swab device in a highly viscous medium can be achieved by weighting it.

Depending on the viscosity of the medium, the weight of the swabbing device is adjusted. The length of the swabbing device may also vary to increase the volume of highly viscous fluid subject to local heating.

The high viscosity fluid may be oil, bitumen, or other well fluid.

Depending on the set goal, swabbing ends after the selection of the required volume of well fluid, stabilization of the inflow from the reservoir, the start of well flowing, etc.

A device for implementing the method is presented in figure 1.

The device consists of blocks: swab device 1, geophysical cable 2, ground equipment 3, cable lug 4, channel 5 of electric energy, converter 6 of electric energy into heat, protective sheath 7.

Swabbing device 1 is connected to ground equipment 3 using a geophysical cable 2 through cable lug 4, providing mechanical and electrical connection.

Swabbing device 1 contains a converter 6 of electrical energy into heat (heater) connected to the electromagnetic valve 4 through the channel 5 of electrical energy.

The converter 6 of electric energy into thermal energy is surrounded by a protective shell 7 made of a material that is heat-conducting and resistant to aggressive downhole media. In one of the embodiments, such may be metal, which allows efficiently transfer heat to the external environment and is not much affected by the well fluid.

The protective shell 7 seals and protects the Converter 6 of electrical energy into heat.

The swab device 1 has a metal body and a rubber sleeve mounted on it, or can be made of any material by any method known in the art.

The device for implementing the method further comprises at least one temperature sensor for collecting telemetric information about the well, located in any part of the swab device 1, but preferably in its lower part.

Telemetric information from the temperature sensor is transmitted to the ground equipment 3 through the channel 5 of electric energy and a geophysical cable 2 to generate current information about the well and to enable the ground equipment 3 to control the swab device 1.

In one embodiment, the device may comprise a typical depth meter located in the ground equipment 3, operating on the principle of measuring the length of the geophysical cable 2 lowered into the well by means of a measuring roller and correcting this depth using magnetic marks applied to the geophysical cable 2 through a certain fixed interval.

Swabbing device 1 to further facilitate the descent (increase the speed of immersion) in a viscous medium must be streamlined elongated, have sufficient mass (in the preferred embodiment, 30 kg and a length of at least 0.5 meters), to be able to increase the load (elongation), have "guides" to reduce resistance to immersion in highly viscous well fluid.

The mass and length of the swab device 1 can be changed depending on the structure of the well and the viscosity of the well medium.

The Converter 6 of electrical energy into thermal energy is made using a heating element, electrochemical heating, with the possibility of induction conversion of electrical energy into thermal energy.

The device operates as follows.

Swab device 1 is lowered on geophysical cable 2 into the well to the boundary with a viscous medium.

They turn on the power and supply electric energy to the swabbing device 1 through a geophysical cable 2 from a source of electric energy located in the ground equipment 3.

Electrical energy through a cable lug 4, providing a mechanical and electrical connection, is supplied to the converter 6 of electric energy into heat through the channel 5 of electric energy to convert it into heat.

An electric to thermal energy converter 6 converts electric energy into thermal energy and transfers it to the environment of the well through a containment shell 7 to locally heat the well fluid and reduce the viscosity of the produced product.

Heating is carried out until the well fluid liquefaction temperature is reached.

At the same time, the swabbing device 1 is smoothly lowered simultaneously under the level of the liquefied well fluid.

Upon completion of the dive to the required depth (for example, 200 meters), the selection and lifting of the borehole fluid by swabbing is performed.

When lifting the swab device 1, the rubber sleeve expands and seals the well, thereby ensuring the selection and lifting of viscous fluid.

Then the whole process can be repeated as many times as necessary until the required injectivity of the well or the required level of well fluid is achieved.

Local heating of the borehole fluid can significantly reduce its viscosity, as a result of which the rate of immersion of the device under the level of the borehole fluid increases and the lifting of the device with extraction of the liquefied borehole fluid to the surface is facilitated.

With the help of a temperature sensor, information on the temperature of the well fluid, onto which the swab device 1 is lowered, is periodically taken. Telemetric information from the sensor is transmitted to the surface via a geophysical cable 2. Using the information received, the control device located in the ground equipment 3 generates control signals about the end of the process of heating, lowering and raising the swab device 1, etc.

Swabbing device 1 must move at a certain predetermined speed, depending on the parameters of the working well, including from the viscosity of the medium in the well. If during the descent to the level of a viscous medium, the speed of the swabbing device 1 is changed (slow down or accelerate), respectively, the amount of electric energy supplied to the swabbing device 1 from the ground equipment 3 is adjusted (increase or decrease). The amount of electrical energy supplied is adjusted to maintain the immersion speed of the swab device not less than 0.3 m / s and not more than 1 m / s. Thus, they achieve the immersion of the swab device 1 to a depth of more than 200 meters in less than 15 minutes.

In a preferred embodiment, the swab device 1 can be equipped with an overheat protection unit, for example, operating on the principle of a temperature relay, which is triggered (stops the transmission of electric energy from the cable lug 4 to the electric energy to heat converter 6) when a certain temperature is exceeded, for example 100 ° C, which corresponds to the maximum pre-set liquefaction temperature of the well fluid.

The invention can be used in hydrophysical studies of wells, in the oil industry when developing wells after repair (repair and insulation works, treatment of bottom-hole zones, enhanced oil recovery and other types of stimulation of inflow from perforated reservoirs using various emulsions); in the production or development of wells after repair, containing in their products highly viscous oil or bitumen.

The claimed invention additionally provides autonomy and mobility of the complex of equipment used, the environmental cleanliness of the swabbing process, and the safety of work.

Claims (17)

1. A method for swabbing a viscous fluid well, comprising the steps of:
pre-lower the swab device to the border with a viscous fluid with a predetermined temperature of at least 40 ° C and not more than 100 ° C;
immerse it under the level of viscous fluid with a predetermined speed of not less than 0.3 m / s and not more than 1 m / s;
electrical energy is supplied directly from the ground equipment using a geophysical cable to the swabbing device, which is then fed through a cable lug through an electric energy channel to the bottom of the swabbing device;
using an electric energy converter located in the lower part of the swabbing device, converting electric energy into thermal electric energy into heat energy and transferring it to the level of a viscous fluid, heating it locally to a fluid dilution temperature with simultaneous descent of the swabbing device;
wherein the descent speed and the temperature of the well fluid are monitored throughout the descent of the swab device;
when the immersion speed of the swab device and the temperature deviate from the set values, the amount of electrical energy supplied from the surface is controlled;
carry out the selection of a viscous fluid and lifting it to the surface using a swab device. 2. The method according to claim 1, characterized in that the local heating is carried out in continuous or intermittent mode throughout the descent of the swab device. 3. The method according to claim 1, characterized in that they regulate the rate of immersion of the swab device in a viscous fluid by weighting it. 4. The method according to claim 1, characterized in that the swab device is immersed under the level of viscous fluid under its own weight. 5. The method according to claim 1, characterized in that they control the swabbing device from the surface. 6. The method according to claim 1, characterized in that they obtain telemetric information about the well from the swab device, conduct its analysis, based on the results of which the control of the swab device from the surface is adjusted. 7. The method according to claim 6, characterized in that the temperature of the well fluid is determined from the received telemetric information about the well. 8. A device for swabbing a well with viscous fluid, comprising a swab device connected to ground equipment, characterized in that the swab device includes a cable lug in its upper part that provides mechanical and electrical connection with a geophysical cable connected to the ground equipment, and in the lower part of it contains a converter of electrical energy into thermal mass of at least 30 kg, connected to the cable lug via an electric energy channel, while the swab device contains at least one temperature sensor and an electric energy regulator on the surface to maintain the temperature of the well fluid at least 40 ° C and not more than 100 ° C and the immersion speed of the swab device at least 0.3 m / s and not more than 1 m / from. 9. The device according to claim 8, characterized in that the cable lug provides mechanical and electrical connection to the channel of electrical energy. 10. The device according to claim 8, characterized in that the converter of electrical energy into thermal energy is surrounded by a protective shell that is in direct contact with the internal environment of the well, resistant to the aggressive environment of the well, and configured to transfer thermal energy to the well. 11. The device according to claim 10, characterized in that the protective shell is made of metal. 12. The device according to claim 8, characterized in that the swab device is made streamlined elongated and with the possibility of changing mass and length. 13. The device according to claim 8, characterized in that the length of the Converter of electrical energy into heat is not less than 0.5 meters and not more than 1.5 meters. 14. The device according to claim 8, characterized in that the electric energy channel and the geophysical cable are configured to transmit telemetry information from at least one temperature sensor to ground equipment. 15. The device according to claim 8, characterized in that the ground-based equipment comprises a device for analyzing telemetric information and controlling a swab device. 16. The device according to claim 8, characterized in that the converter of electrical energy into thermal energy is made using a heating element, or electrochemical heating, or with the possibility of induction conversion of electrical energy into thermal energy. 17. The device according to claim 8, characterized in that the swab device further comprises an overheat protection unit.

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