WO2013051958A1

WO2013051958A1 - Method for reviving the working condition of a well and technical complex for the implementation of same

Info

Publication number: WO2013051958A1
Application number: PCT/RU2011/000958
Authority: WO
Inventors: Виктор Иванович ГАПЕТЧЕНКО; Игорь Борисович ПУЛЬНИКОВ
Original assignee: Gapetchenko Viktor Ivanovich; Pulnikov Igor Borisovich
Priority date: 2011-10-07
Filing date: 2011-12-05
Publication date: 2013-04-11
Also published as: RU2011140616A; RU2482268C1

Abstract

The group of inventions relates to the oil and gas industry and is intended for reviving the working condition of a well during production. The method for reviving the working condition of an oil and gas producing well comprises three stages. In the first stage, geophysical measurements of the well parameters are made, on the basis of which an inflow profile is established for the portion of the well under observation and "nonproductive" intervals are identified. In the second stage, the portions of the well that exhibit nonproductive intervals are flushed of technical fluids. In the third stage, control measurements of the geophysical parameters of the well are made and qualitative and quantitative characteristics of the production rate in the nonproductive intervals are determined. The technical complex for the implementation of the method comprises two assemblies with coiled tubing. The first comprises a geophysical cable for the connection and delivery into the well of a geophysical instrument, and the second coiled tubing assembly serves to flush the bottom hole portion of the well. Furthermore, the second coiled tubing assembly is adapted for connection to the hydraulic system of the first coiled tubing assembly and to the well flushing equipment. The claimed group of inventions provides an increase in the production rate of a working well by harnessing the nonproductive portions of a horizontal or inclined well shaft.

Description

METHOD FOR RECOVERING A WORKING CONDITION OF A WELL AND A TECHNOLOGICAL COMPLEX FOR

ITS IMPLEMENTATION

1. The technical field

The group of inventions (method and installation) relates to the oil and gas industry and may find application in well operation. In particular, the group of inventions is intended to restore the working condition of the well during operation and can be used in the repair and development of wells, as well as in the implementation of geological and technical measures to intensify oil and gas production. The group of inventions can be applied in horizontal fountain wells with planted formation pressures, the flow rates of which fall due to the accumulation of water at their bottom.

2. The prior art

The invention is based on the use of coiled tubing technology (flexible tubing) with a “charged” geophysical cable. For coiled tubing used in oil refineries, and representing a flexible metal pipe, wound onto a drum with a diameter of 5 m or more, the term “coiled tubing” (www.fidrnashnov.com) is used. This technology allows you to carry out various work in horizontal and subhorizontal wells, in particular, to conduct various types of research in the well and to obtain information about the well in real time without stopping the working well. In addition to monitoring downhole processes, coiled tubing technology with a geophysical cable can be used to deliver to a horizontal and subhorizontal well any standard field-geophysical equipment and equipment and carry out the corresponding work.

There are various methods and devices based on the use of CT, separately for conducting geophysical surveys, for delivering geophysical equipment to the well, as well as for cleaning wells. However, the prior art does not know the technologies that provide a comprehensive solution tasks of effective restoration of the working condition of the well during operation, with horizontal and / or subhorizontal completion.

In particular, a tool kit for the geophysical “Coiled Tubing” is known (Utility Model Patent Ν ° 80694, IPC: E21B47 / 00), which has the ability to perform a wide range of geophysical work. “Coiled tubing” includes a geophysical elevator with a geophysical cable; drum with wound geophysical cable; High pressure pump; tank with liquid; a tank for draining excess fluid from the well; node for connecting tanks; tools at the end of the cable, namely: a fluid rotary cutter; nozzle with holes for cleaning pipes with liquid; a nozzle for supplying acids and surfactants to the well; cement nozzle; a nozzle for supplying bulk materials to the well; inflatable packer; jet pump to lower the level of fluid in the well; jet pump with packer for quick pressure reduction under the packer; accessories and valves for regulating the operation of the jet pump; piercing punch; implosive catcher; spray gun on the surface; hydraulic tractor; jet nozzles; hydraulic fracturing equipment; equipment for washing the filter in the formation zone; equipment for water hammer on the reservoir; equipment for impacting the formation with variable pressure; accessories for accelerated determination of the pressure recovery curve; equipment for accelerated formation flow rate determination; equipment for fluid production in low-production wells with low and ultra-low reservoir pressure; equipment for the extraction of heated water from a produced well; equipment for reducing borehole pressure in the cable tube; snap with a rotating brush; equipment for a hydraulic trap; hydraulic scraper; equipment for feeding into the well by cable with a tube of carbonated liquid; equipment for geophysical research; other equipment driven by fluid pressure; other accessories driven by electric current. Using the proposed universal and inexpensive utility model makes it possible to perform a wide range of geophysical works.

The well-known set has a wide range of equipment and tools for carrying out various geophysical works, can solve a wide range of problems, and provides universal installation. However, the tools listed in the utility model are not enough to efficiently and economically restore the well’s working condition. A known method of operation of a coiled tubing-ejector installation in a gas lift oil well (patent for the invention 2404373, IPC: F04F5 / 54). The invention is aimed at creating a highly cost-effective way of operating a downhole ejector installation with the possibility of carrying out a range of works on testing and processing productive formations and organizing production of formation fluid from gas lift wells. The method of operation of a coiled tubing-ejector installation in a gas lift oil well with a string of tubing and tubing and a packer is to lower a liner with an inlet funnel, a packer and a support body installed sequentially from the bottom up to the tubing string (KGT), for ejection device. The KGT packer is located above the tubing packer, and the inlet funnel is located above the top of the reservoir. The KGT packer is unpacked, an acid solution is pumped into the reservoir through the KGT and the casing support, then a hydrodynamic ejection device is installed in the casing support through the KGT with an independent pressure gauge installed underneath it and by applying pressure through the annular space between the outer surface of the CGT and the inner surface The tubing of a liquid working agent, for example oil or condensate, into the nozzle of a hydrodynamic ejection device creates a depression on the reservoir and drains it the near-zone of the reaction products of an acid solution with the formation. After pumping out the reaction products from the reservoir, the supply of the working agent to the nozzle of the hydrodynamic ejection device is sharply stopped, while the check valve of the hydrodynamic ejection device installed in the channel for supplying the pumped medium is automatically closed, and the formation pressure recovery curve (HPC) is recorded in the under-packer space. After registering the HPC using a wireline technique, a hydrodynamic ejection device with an autonomous pressure gauge is removed to the surface and a complex geophysical device with a geophysical ejection device movably mounted above it on the wireline is lowered into the borehole on the wireline through the CTG. During the descent, the background geophysical parameters, for example, pressure and temperature, are recorded along the wellbore from the KGT inlet funnel to the bottom of the well using the integrated geophysical instrument, while the geophysical ejection device is installed in the support body. Next, by filing under pressure along the annular space between the outer surface of the CT and the inner surface of the working agent tubing, a depression is created in the nozzle of the geophysical ejection device to the reservoir, the reservoir is drained until the inflow is stabilized, then with the working geophysical ejection device using the logging cable, the integrated geophysical device is lifted to the KGT inlet funnel, recording the well’s geophysical parameters. The geophysical ejection device is shut down and a complex geophysical device with the geophysical ejection device is removed from the well to the surface, the hydrodynamic ejection device with an autonomous pressure gauge is dropped into the QGT, and it is installed in the support housing by applying pressure through the annular space between the outer surface of the QGT and The tubing into the nozzle of a hydrodynamic ejection device of natural gas creates depression on the reservoir, under the influence of A new formation fluid, in particular oil, through the inlet of the pumped-out medium, the gap between the nozzle exit and the mixing chamber exit, the mixing chamber and the diffuser of the hydrodynamic ejection device enters the QGT and, together with natural gas, rises to the surface as a result of the ejector gas lift and conduct production formation fluid. After the flow rate of the formation fluid drops, the natural gas is replaced by oil or condensate, the supply of the working agent to the nozzle of the hydrodynamic ejection device is abruptly stopped and the HPC is recorded in the under-packer space, after which the hydrodynamic ejection device, together with the autonomous pressure gauge, is removed to the surface and the well a complex logging tool with a geophysical ejection device movably mounted above it and using a complex logging tool zhnogo device tested wellbore section from the inlet to the funnel during operation downhole geophysical ejecting apparatus, recording the inflow profiles and determining sources watering substituted liquid working agent for natural gas. They stop the supply of natural gas to the nozzle of the geophysical ejection device, remove the integrated logging tool with the geophysical ejection device from the well, and carry out measures to restore the productivity of the well in the formation fluid through the CT and the support body: water-proofing, shooting the reservoir in depressive mode with the help of small-sized perforators run on a logging cable, or acid treatment of the formation, and then repeated hydrodynamic and geophysical studies described above and again start the well into operation using an ejector gas lift.

The implementation of this method extends the functionality of the borehole coiled tubing-ejector installation. However, this technology also does not provide sufficient efficiency and economy of the process of restoring the working condition of the well.

3. Disclosure of invention

The objective of the claimed group of inventions is to increase the flow rate of hydrocarbons in a working well by "connecting" "idle" sections of the horizontal / subhorizontal wellbore without major repairs. The inventive solutions ensure that the task without stopping (without killing) the well. The technical result consists in the implementation of a set of measures to increase the efficiency of the work.

The problem is solved in that the method of recovering the operating state of an oil and gas producing well with horizontal and / or subhorizontal completion during operation includes three stages, the first of which delivers geophysical instruments to the well, using which the geophysical parameters of the well are measured, including within the horizontal part of the wellbore, which determine the profile of the inflow of the investigated section of the well with the allocation of "idle" intervals, per W rum step is performed by washing the wellbore fluids of man-made portions corresponding to the identified "inoperative" intervals inflow profile, in the third step is carried out of the well test measurements of geophysical parameters determining qualitative and quantitative characteristics debit portions isolated in the first step as "idle". If “non-working” sites are identified based on the results of geophysical measurements in accordance with the third stage, the washing of “non-working” sites is repeated. To determine the inflow profile of the studied section of the well, the following geophysical parameters are measured: the natural radioactivity of the near-wellbore rocks, the induced radioactivity of the near-wellbore rocks, the number of coupling joints and other metal structures of the well string and the distance between them, temperature, pressure, current flow rate along the wellbore, the percentage of liquid and gas-water-oil components present, the specific resistance of the fluid along the wellbore, the coordinates of the wellbore, well pressure, acoustic noise; the measured parameters determine the actual design of the well and the technical condition of the string, the level of filling the wellbore with fluid in the working and stopped wells, the density of the fluid along the wellbore, reservoir pressure, production rate, annular pressure, bottom-hole pressure, bottom-hole temperature, and working intervals are calculated with the determination of the percentage of total flow rate and quantitative parameters with an interval breakdown, the determination of annular flows, while measured and read parameters are displayed visually on the tablet. In addition, downhole fluid samples are additionally taken to determine its origin. The delivery of geophysical instruments for measuring the geophysical parameters of the well is carried out using a unit with a first column of flexible tubing, equipped with a geophysical cable located inside the flexible tubing that can be connected to geophysical instruments, while the latter is filled to prevent deformation of the flexible pipe technological fluid, and flushing sections of the well from technogenic fluids that correspond to the identified "idle" intervals of the inflow profile in a near portion of the horizontal / subhorizontal wellbore portion carried by the second column without cable inside coiled tubing adapted to connect to the installation with the first column of coiled tubing. During the delivery of geophysical equipment, the pressure of the process fluid as the coiled tubing is immersed in the well is changed to a value commensurate with the reservoir pressure, while the differential pressure in the string between the coiled tubing and wellhead pressure is maintained in the range of 90-150 atm depending on the depth of the well.

As the working fluid can be used a fluid characterized by a minimum coefficient of thermal expansion, dielectric properties, anticorrosion properties, and not freezing to -60 ° C. These parameters correspond, for example, transformer oil, diesel fuel, crude oil, or mixtures of these liquids. For flushing the coiled tubing string is lowered to the “idle” section of the well, while first injecting a chemical reagent into the string, which takes a substance with foaming properties, which reduces the surface tension of the fluid in the well by at least 2 times, and then nitrogen gas for providing rise from the bottom of the foamed aqueous solution. The injected chemical reagent and gaseous nitrogen are taken in the volume corresponding to the volume of filling the “idle” section of the well before the bottom; the injection rate of the chemical reagent, gaseous nitrogen and the rate of descent of the coiled tubing are selected to ensure uniform distribution of the chemical reagent in the idle interval, while the time of the start of injection of the chemical reagent and gaseous nitrogen into the coiled tubing string are selected depending on the conditions for the beginning of the release of the chemical reagent from the pipe string when entry in the "broken" wellbore portion, and the beginning of outlet gas of nitrogen - when reaching the well bottom, then begin lifting the tubing string with a minimum speed and a continuation of nitrogen injected into the bottom zone formation "idle" portion, thereby allowing removal of fluid on the surface of the formation. The movement of the pipe string along the “idle” section during the injection of chemical reagent and gaseous nitrogen into the column is carried out at a speed of 3-5 m per minute.

The problem is also solved by the fact that the technological complex for the recovery of the operating state of an oil and gas producing well with horizontal and / or subhorizontal completion includes at least two mobile units with a coiled tubing connected to wellhead equipment with a flare line in accordance with the production cycle, one of which designed for geophysical research and the delivery of instruments and tools to the well, and the second for flushing the bottom of the well; as well as a geophysical station with a set of geophysical instruments connected to the first coiled tubing installation, equipment for flushing "idle" sections of the well, the first installation consisting of a coiled tubing drum, injector with a guiding groove (gooseneck), a preventer block, a sealer and a manipulator, equipped with a hydraulic drive, an additional hydraulic high-pressure pump to maintain the required pressure process fluid in a flexible pipe, while the geophysical cable for transmitting the data recorded by geophysical instruments is placed in the CT pipe, and the connection of the geophysical instruments with the CT string is sealed by means of an adapter node — a connector with a special connector — a cable lug, the second installation with CT is designed to flush the bottomhole part of the well, is located on a movable platform, for example, a platform of a vehicle, a drum with a coiled tubing string, made with possibility of connection to the hydraulic system of the first installation of coiled tubing and to the equipment for the washing of the well. The equipment for flushing "non-working" sections of the well includes a mobile nitrogen unit, which includes transportation tanks with liquid nitrogen, a nitrogen convector for converting liquid nitrogen into gaseous, a pumping unit for supplying a chemical reagent, and a recirculation tank for formation fluid connected to the wellhead through a unit for downhole fluid fitting, as well as a pumping unit for loading formation fluid into transportation containers for subsequent disposal, while the main unit and the mobile nitrogen unit through high pressure pipelines through the high pressure manifold are connected to the coiled tubing string of the second coiled tubing unit for flushing the bottom of the well. The first and second installations with a coiled tubing string are located parallel and at a distance from each other, which ensures the placement of the flexible pipes of the installations in the injector without dismantling the surface downhole equipment. The first and second coiled tubing installations are located relative to each other with the formation of an angle between their flexible pipes at the point of connection to the wellhead equipment up to 25 °. The hydraulic pump of the first coiled tubing installation has an electric drive and is mounted on a subframe in close proximity to the drum with the coiled tubing string and connected to the drum with a high pressure pipeline. The geophysical station is a mobile complex that includes a geophysical unit, a universal power source for geophysical instruments, a switching unit, an uninterruptible power supply, and a plotter. The set of instruments for geophysical exploration contains instruments of the PO 50 and SLM brand for recording inhomogeneities of the string and tubing, as well as complex instruments KSAT-43GR and PLT-9.2 for conducting flowometric studies. The set of equipment for flushing a well contains a flushing nozzle, a connector used to connect the coiled tubing string to the flushing nozzle, a check valve block that allows fluid and gas to be pumped into the well and preventing the flow of fluid into the coiled tubing, with the flushing nozzle made with calibrated holes to create a head fluid and gas flow. The connector is made with the possibility of filling in the CT and connecting the pipe to the cable lug, while the cable lug is a part of a prefabricated structure with a central through hole for cable placement and includes a sealant connected to the connector, a geophysical cable attachment, an articulated mechanism designed to give flexibility to the cable tip, cable head, made with the possibility of connecting a geophysical instrument. The connector is made with the possibility of filling in the CT and connecting the pipe to the cable lug, while the cable lug is a prefabricated part with a central through hole for cable placement and includes a cable adapter connected to the connector, a sealant, a single-hinged mechanism, a cable head made with the possibility of connecting geophysical instrument.

4. Brief Description of the Drawings

The group of inventions is illustrated by drawings, where: Fig. 1 shows a schematic diagram of the arrangement and connection of equipment of the claimed technological complex on the territory of a cluster site during work; figure 2 is a flow diagram of the connection of the CT and the geophysical station with a horizontal section of the well; Fig. 3 is a schematic illustration of the construction of a coiled tubing installation connected to the ground part of the downhole equipment, side and top view; figure 4 is a General view of the cable lug for connecting located in the string of the coiled tubing cable with a geophysical instrument; figure 5 is a longitudinal section of a connector for connecting a flexible pipe with a cable lug; figure 6 - sealant used in the first embodiment of the cable lug; in FIG. 7 - adapter cable lug; on Fig, 9 - options for the articulated mechanism of the cable lug; figure 10 - head cable lug; figure 1 1 - sealant used in a second embodiment of a cable lug; on Fig - the results of geophysical surveys in the form of a tablet.

The positions in the figures indicate: 1 - well; 2 - the first installation of coiled tubing; 3 - geophysical station, which can be placed on the trailer of the ZiL-131 automobile, equipped with a mechanical workshop with a diesel generator; 4 - the second installation of coiled tubing or a car with a coil SCTC for flushing the well; 5 - pumping unit; 6 - containers for liquid nitrogen; 7 - nitrogen convector; 8 - high pressure manifold; 9 - recirculation tank; 10 - a check-manifold for connecting the well fluid; 1 1 - pumping unit for downloading formation fluid; 12 - holding crane; 13 - operator's cab; 14 - drum with coiled tubing; 15 - injector; 16 - guiding channel (gooseneck); 17 - block preventers; 18 - sealant (for the 1st version of the cable lug); 19 - manipulator; 20 - wellhead equipment; 21 - high pressure hydraulic pump; 22 - geophysical cable; 23 - CT; 24 - cable lug; 25 - connector; 26 - pusher; 27 - sealant; 28 - cable adapter (geophysical cable mounting unit); 29 - connecting node; 30 - hinge mechanism; 31 - cable head; 32 - connector housing 25; 33 - annular grooves on the surface of the connector housing 25; 34 - grooves on the surface of the connector housing 25; 35 - sealing rings; 36 - sealant body 27; 37 - rubber seals of the sealant 27; 38 - sleeve sealant 27; 39 - nut of the sealant 27; 40 - cable adapter housing 28; 41 - a glass adapter cable 28; 42, 45 - screws of the cable adapter 28; 43 - cone adapter cable 28; 44 - washer adapter cable 28; 46 - hinge of the swivel mechanism 30; 47 - glass swivel mechanism 30; 48 - clutch swivel mechanism 30; 49 - sealant (for the 2nd version of the cable lug); 50 - the case of the sealant 49; 51 - insulated conductive line of the sealant 49; 52 - sealed contact seal 49.

5. The best embodiment of the invention

The inventive method includes three stages, the first of which carry out geophysical studies to determine the profile of the influx ("working" and "idle" intervals) within the horizontal / subhorizontal part (section) of the wellbore using a "coiled tubing" installation (coiled tubing) 2 (figure 1) connected to the ground part of the wellhead equipment 1 (FIGS. 2, 3) and the geophysical station 3. Moreover, the flexible pipe in the installation is equipped with a geophysical cable located inside it. At the second stage, the technological fluids are cleaned (flushed) of the bottom-hole portion of the horizontal / subhorizontal section of the well corresponding to the identified “idle” sections of the inflow profile using the second CT 3 installation or a replaceable drum (coil) with a CT string without a cable inside. At the third stage, repeated “control” geophysical surveys of the well are carried out.

At the first stage, to measure the geophysical parameters of the well, a flexible pipe with measuring instruments is lowered into the well, while the flexible pipe is equipped with an armored cable located inside it with a conductive core (for power supply, control and measurement of parameters), as well as a docking module for a flexible pipe and a geophysical cable with downhole tool. The docking module is a cable lug (figure 4) with an axial hole (channel), equipped on the side of the connecting to the flexible pipe with a sealing unit - connector (figure 5), through which the end of the cable is passed for connection with the geophysical instrument. Before conducting research, the coiled tubing string is filled with process (working) fluid under excess hydrostatic pressure to provide the required backpressure to the reservoir (P reservoir to 70 MPa) and to reduce the effect of external pressure on the collapse of the pipe during the study. During the delivery of geophysical equipment, the pressure of the process fluid as the coiled tubing is immersed in the well is changed to a value commensurate with the reservoir pressure, while the differential pressure in the string between the coiled tubing and wellhead pressure is maintained in the range of 90-150 atm depending on the depth of the well. To create excess pressure in the flexible pipe, the coiled tubing unit is equipped with a high pressure pump. Transformer oil or another liquid with a minimum coefficient of thermal expansion (0.0007), dielectric properties, anticorrosion properties, certain viscosity parameters, and not freezing in the range up to - 60 ° C (when transported on a drum “ coiled tubing installation). The following instruments can be used to measure geophysical parameters in a well:

- PO 50 and SLM 43, with the help of which the technical condition of the string and tubing (tubing) is recorded, and which can be used as templates due to their resistance to loads;

- complex instruments KSAT-43GR and PLT-9.2 (in assembly with the PLT-01.42 module), providing flowmetric studies that can simultaneously be used for radioactive logging (measuring the natural radioactivity of rocks), location of couplings and holes (determining the technical condition of well strings and tubing), induction resistivimetry (determination of electrical resistivity or conductivity of a well fluid), moisture measurement (determination of the dielectric constant of a fluid filling a wellbore ), thermometry (determination of the temperature gradient along the wellbore); thermoconductive flow measurement (identification of the intervals from which fluid flows into the wellbore and estimates of its volume (flow rate) for each formation), mechanical flow measurement (determination of fluid flow velocity along the wellbore), manometry (determination of pressure gradients, which determine the fluid velocity in the reservoir, and the rate of development of reserves).

Geophysical parameters are measured both in a working well and in a stopped (closed) well.

The data of downhole geophysical instruments via logging cable are transmitted in real time to the equipment of the geophysical station, where they are digitally recorded by the Kedr - 2 / 1.5 ground-based geophysical logger and converted into LAS format for interpretation. The processing process takes place in the comprehensive program “GEOPOISK”, the HPC processing is performed in the “GEKKON” system for gas wells or “GEOTEK”. In the process of interpretation, the registered parameters are converted from conventional units to physical ones and processed to obtain reservoir operational characteristics (establishing the nature of the current saturation, identifying the inflow intervals, determining the total flow rate, and distributing the flow rate over individual reservoirs separated by clay bridges, and constructing a flow profile at individual intervals, determining the composition of the well fluid, identifying watering intervals, determination of pressure and temperature in the interlayers and in the reservoir as a whole, assessment of the technical condition of the production string and tubing. Based on the measurement results, a consolidated geophysical tablet is built. When constructing a tablet, geophysical data obtained during open-hole operations (background curves for reference, lithology, and resistance curves) are used. The results are used to plan measures to increase the efficiency of reservoir development, regulate the flow profiles, and improve the quality of the formation opening (Fig. 12).

Thus, according to the measurement results, the inflow profile is built, the level, composition and density of the fluid in the wellbore are determined, the filtration parameters are recorded with the pressure recovery curve in the stopped well without involving the services of the well workover team. If necessary, borehole fluid is sampled using a controlled in-depth sampler to determine its origin (produced water, or technogenic fluid). The borehole fluid sample can be sampled with a SLM 43 (coupling locator) with the recording of the coupling locator from the upper section of the detailing interval to the depth of sampling during the descent and lifting of the device.

At the second stage, the technological fluid is cleaned (rinsed) from the bottom-hole part of the horizontal (subhorizontal) section of the well corresponding to the identified “idle” sections of the inflow profile using an interchangeable drum with coiled tubing without cable inside the flexible pipes. Washing can be carried out using various technologies, including the gas-lift method. At the same time, the method is of great efficiency, according to which, for flushing the coiled tubing string, it is lowered to the “idle” section of the well, while first injecting a chemical reagent into the string, using a substance with foaming properties, which reduces the degree of surface tension in the well liquid at least 2 times, and then gaseous nitrogen to ensure the rise from the bottom of the foamed aqueous solution. The injected chemical reagent and gaseous nitrogen are taken in a volume corresponding to the volume of filling the “idle” section of the well before the bottom, which is calculated based on the geometric parameters of the well measured at the first stage. Chemical injection rate nitrogen gas and coiled tubing descent rate are selected to ensure uniform distribution of the chemical reagent in the idle interval. At the same time, the start time of the injection of the chemical reagent and gaseous nitrogen into the coiled tubing string is selected depending on the conditions for the start of the release of the chemical reagent from the pipe string when the entrance to the “idle” section of the well is reached, and the start of the release of gaseous nitrogen when the bottom of the well is reached, after which they start lifting the pipe string with a minimum speed and continuing the injection of nitrogen into the bottom-hole zone of the “non-working” section of the formation, thereby ensuring the removal of fluid to the surface of the formation. The movement of the pipe string along the “idle” section during the injection of chemical reagent and gaseous nitrogen into the column is carried out at a speed of 3-5 m per minute. As a chemical reagent can be used industrial surfactants.

At the third stage, repeated “control” geophysical surveys of the well are carried out with the same tasks as in the first stage.

The following is presented in more detail the claimed technological complex for the recovery (recovery) of the operating state of an oil and gas producing well with horizontal and / or subhorizontal completion during operation (Fig. 1 - 1 1), which contains equipment for conducting geophysical surveys interconnected in accordance with the technological cycle and washing the bottom of the well, including two mobile installations with coiled tubing.

The first installation with coiled tubing 2, designed for geophysical exploration and the delivery of necessary equipment to the well, consists of mounted on a subframe located, for example, on the MAZ-631708 base chassis, operator’s cab 13, coiled tubing 14, injector 15 with a guide channel ( Gooseneck) 16, block of preventers 17, sealant 18 and manipulator 19. The drive of all installation mechanisms is hydraulic, with power take-off from the base chassis engine. The coiled tubing string at the installation is located on the drum of the winding unit, which provides for its winding-winding during tripping operations, as well as the supply of technological fluid pumped into flexible pipes into it. Coiled tubing is a long seamless metal pipe, for example, 4200 meters long with an external diameter of 25.4 mm. A single core cable is placed in a coiled tubing armored geophysical cable with a diameter of 5.4 mm for transmitting data recorded by geophysical instruments, while the instruments are delivered to the well by a CT pipe. Launching and lifting the coiled tubing into the well is carried out by an injector 15, on which a guiding chute (gooseneck) is installed 16. Sealing of the wellhead during tripping operations is carried out by the sealant 18, and in emergency situations during the repair of wells without killing them, it is carried out by the preventer unit 17. Installation and dismantling the block of preventers 17 and injector 15 to the wellhead equipment 20 is carried out using a manipulator 19 located on the rear of the subframe, or a truck crane 12. Installing the CT olnitelno comprises a hydraulic high-pressure pump 21 to 700 atm (Enerpak) with an electric drive to maintain the desired pressure of the process fluid in the flexible tube, wherein the pump is mounted on the stretcher in close proximity to the drum and coiled tubing coupled with the drum a high pressure pipeline.

Geophysical station 3 is also a mobile complex that can be placed on a car trailer, for example, ZiL-131 brand, equipped with a mechanical workshop with a diesel generator. The geophysical station includes replaceable blocks located in the body: a geophysical block (BGF); universal power source for geophysical instruments (UIP); switching unit (BC); uninterruptible power supply (UPS); plotter.

The flushing equipment (Fig. 1) includes a second coiled tubing unit 4 connected by a technological cycle, which is a coil with a coiled tubing string located on a moving platform (for example, a vehicle platform), configured to connect the first coiled tubing unit 2 to the hydraulic system, a pump unit 5 with a permissible fluid injection pressure of up to 1000 atmospheres, a mobile nitrogen unit (PAH), which includes transport containers 6 with liquid nitrogen, a nitrogen convector 7 for conversion liquid nitrogen to gaseous. The pump unit 5 and PAHs through high pressure pipelines through the high pressure manifold 8 are connected to the coiled tubing string of the second unit 4, designed to flush the bottom of the well. The equipment also contains a recirculation tank 9 for reservoir fluid connected to the wellhead through the borehole fitting block fluid 10 (check-manifold), as well as a pump unit 1 1, for example, ЦА-320. for downloading formation fluid into shipping containers for subsequent disposal. The first and second installations with a coiled tubing string (2 and 4) are located relative to each other with the formation of an angle between their flexible pipes at the point of connection to the wellhead equipment 1 of the well up to 25 °. This arrangement ensures the placement of the flexible pipes of the plants in the injector 15 (FIG. 3) without dismantling the surface downhole equipment and without constructive intervention in the injector.

To connect logging tools and tools with a coiled tubing string, a special adapter assembly (connector 25) and a special connector (cable lug 24) are used (Figs. 4, 5). These devices have an original constructive solution, while the cable lug has two options for ensuring a tight connection to the CT. The tool kit used for logging is shown above. To flush the well, a nozzle with holes and check valves is installed in the lower part of the column, preventing the well fluid from entering the coiled tubing when the process fluid is stopped.

The connector 25 is made with the possibility of refueling in the CT 23 and connecting the pipe to the cable lug 24, while the cable lug 24 is a part of a prefabricated structure (Fig. 4) with a central through hole for accommodating the cable 22. The first embodiment of the cable lug 24 includes sequentially arranged a sealant 27, which serves to seal the coiled tubing with oil, a geophysical cable mount (cable adapter) 28, an articulated mechanism 30, designed to give flexibility to the cable th tip, cable head 31 adapted for connection geophysical instrument. In this case, the sealant 27 is connected to the mounting unit of the geophysical cable 28 through the pusher 26, and the mounting unit of the geophysical cable 28 is connected to the hinge mechanism 30 through the unit 29. Thus, the cable from the CT through the connector is fed into the sealant, then it is rigidly fixed in the adapter cable 28, then passes through the swivel mechanism 30 and connects to the underground part of the geophysical equipment through a cable head 31 containing a socket for connecting geophysical instruments. The housing 32 of the connector 25 (Fig. 5) is made on the side of the external surface profiled with a step change in the external diameter, ensuring a tight fit of the CT on the housing of the connector 25. At the same time, on the side of the external surface of the housing having a smaller diameter, annular grooves 33 are made for fixing the connector 25 inside the coiled tubing by deformation of the flexible pipe along these grooves using a seaming mechanism (connector roll). To prevent the penetration of the process fluid from the coiled tubing cavity into the well cavity, additional grooves 34 are made between adjacent grooves 34 to accommodate the sealing rings 35 (for example, from PCB or rubber). At the same time, to increase the tightness, the groove may have a geometry that ensures the placement of two sealing rings in it having the same thickness but different cross-sectional profiles, for example, rectangular and oval. It is optimal to place between adjacent annular grooves 33 of at least two grooves 34 with the indicated geometry and with a pair of sealing rings placed in each of them.

The connector 25 is connected to the sealant 27 (Fig.6), the housing 36 of which is also a cylindrical part with profiled external and internal surfaces. A cavity is formed in the housing 36 to accommodate the rubber seals 37, while the rubber seals are made with a central hole having a smaller diameter compared to the diameter of the geophysical cable, i.e. compressing the geophysical cable, which ensures tight cable placement in the sealant. Two (or more) seals can be placed in the housing 36, separated by a sleeve 38. The connector 25 is connected to the geophysical cable mounting unit 28 through a pusher 26, which serves to squeeze the rubber seals 37 and isolate the interior of the CT from the well, the connection of the pusher 26 with the connector 25 is made by means of a thread. The pusher is locked against spontaneous unscrewing by the lock nut 39.

Cable adapter 28 is designed for rigid fixation of the geophysical cable (Fig.7). For this, the outer armor of the cable is first fixed in the cup 41, while the outer winding of the cable is placed between the cup 41 and the cone 43, after which the washer 44 is installed and clamped with a screw 45. The assembled structure is inserted into the housing 40 and clamped with a screw 42. In FIG. 8 and 9 show two options for performing the articulated mechanism. The hinge mechanism shown in FIG. 8 is made in the form of an arrangement of two ball joints 46, the spherical parts of which are fixed in the cups 47, and the cylindrical parts are rigidly interconnected by means of a coupling 48. In FIG. 9 shows a single-hinged version of the layout.

In the claimed design for connecting a geophysical instrument, a standard cable head (Fig. 10), for example, manufactured by Fidmash (Minsk), can be used. In this case, the geophysical cable is connected to the head by means of a tight contact.

The second embodiment of the cable lug (a modified part of which is shown in FIG. 1 1) is a connector 25 connected in series, a cable adapter 28, a sealant 49 (having a different design solution), a single-hinged mechanism 30, a cable head 31. In this case, the connector 25 has a design similar to that shown in FIG. 5. Cable adapter 28 has a design slightly different from that shown in Fig. 7, namely, it is made with smaller overall dimensions and, on the connection side with the connector, is equipped with a corresponding “docking” part, which ensures its connection with the connector housing 25. In this case, the outer diameter the connector 25 is equal to the outer diameter of the housing 40 of the cable adapter 28 and the outer diameter of the CT. The sealant 49 of the new design is a housing 50 with an insulated conductive line 51 mounted in its body, while the outer diameter of the housing 50 is equal to the outer diameter of the CT. The connection of the geophysical cable with the conductive line 51 is carried out by means of a sealed contact 52, which is made with the possibility of hermetic and safe connection (connection) of the housing of the sealant 49 with the housing of the adapter cable 28. Moreover, the contact 52 has a structure that ensures its tightness in the process of screwing the housing of the sealant 49 to the housing of the cable adapter 28. The single-joint mechanism 30 and the cable head 31 in this embodiment of the cable lug have a design similar to 9 and 10, respectively.

Thus, a flexible pipe (CT) is an ideal means of delivering equipment, both for conducting geophysical surveys and for carrying out technological work, at the desired point in the well. At the same time, the geophysical cable is located inside the pipe, which allows you to control the processes of descent - lifting a CT with a GIS instrument and making measurements in the οη-line mode. Using coiled tubing significantly improves the quality of work and the reliability of the information received. This is due to the higher longitudinal stiffness of the flexible pipes compared to the geophysical cable. Measurements can be carried out during the descent and ascent of the instrument, with the required speed according to the GIS technology. All these operations are performed without prior killing of the well. In addition to instruments, perforators and any other geophysical equipment can be lowered on a string of flexible pipes. Coiled tubing is a reliable means for their delivery to the zones of horizontal and subhorizontal wells.

The technological complex operates as follows. The equipment of the complex is placed on a well pad and connected according to the described scheme to the well. Using the coiled tubing installation 2 and the geophysical station 3, the geophysical parameters are measured according to the first stage of the method, and using the washing equipment 4 - 1 1, the bottom-hole part of the well is washed, according to the second stage of the method. To do this, the CT-4 installation is connected to the injector 15 of the CT-2 installation, the hydraulic hoses from the working coil of the CT-2 installation are connected to the working coil of the CT-4 installation. In this case, the cars are installed so that the flexible pipes at the point of connection to the injector are at an angle of 10 - 25 °. For washing, the pipe from the CT 4 installation is lowered into the well. At the moment when the coiled tubing begins to approach the bottom of the well, on the manifold 8, the valve is opened and the pump 5 starts pumping the chemical (foaming) reagent from the tank 9 with the conditions described above under which the foaming agent is mixed with the liquid at the bottom of the well. In this case, the coiled tubing is lowered to the bottom with a minimum speed and a calculated amount of a chemical reagent to create a foaming solution with a low coefficient of surface tension. Having reached the bottom, the injection of the reagent is stopped and the injection of gaseous nitrogen begins. To do this, on the manifold 8, close the valve to the pump 5 and open the valve to a mobile nitrogen installation (PAH). Under the pressure of gaseous nitrogen, the liquid with the foaming agent begins to rise to the surface of the borehole, the specified fluid through the manifold 10 is sent to the recirculation tank 9, from which it is disposed of by the pump unit 1 1. In order to inject gaseous nitrogen into the last well did not break through the fluid with the blowing agent (since the fluid with the blowing agent has a density greater than nitrided gas), by means of the check manifold 10, the wellhead pressure in the well is 10-15% higher than the reservoir pressure. At the moment when the fluid stops flowing from the well and clean gas starts to flow from it, on the check-manifold 10 they close the valve to the recirculation tank and open the valve to the flare line. After step 2, step 3 is carried out to determine the quality of the flushing. After the stage of washing the bottom of the well, repeated “control” geophysical surveys are carried out, with the determination of the qualitative and quantitative characteristics of the flow rate of the sections identified as “inoperative” in the first stage. According to the results of a comparative analysis of the measurement results before and after flushing the "idle" sections of the well, a qualitative and quantitative conclusion is made about an increase in the well flow rate.

Using the proposed method and technological complex, work was carried out to restore the working condition of the oil and gas producing well of the Zapolyarnoye field with a subhorizontal ending (in the wells of the Senoman deposits with a depth of up to 1700 meters and a horizontal section of up to 400 meters). According to the claimed method, all three stages were implemented: a geophysical study of the well, flushing the well, re-geophysical study of the well. The work was carried out using the MCU UT Coiled Tubing Unit using the Global tubing USA flexible pipe with cable, the Kedr geophysical station, as well as using the KSAT-43 GR geophysical downhole tools; PLT-9.2; module PLT-02; locator couplings SLM-43; cutters for cleaning the walls of the well, as well as other auxiliary equipment. In the coiled tubing installation, a 4200-meter-long pipe with a diameter of 25.4 mm was used. A single-core armored geophysical cable with a diameter of 5.4 mm was placed in a coiled tubing pipe. The installation worked in the well without killing them at a pressure on the sealed wellhead up to 70 MPa.

At the well, pressure, temperature, dielectric constant, electrical resistivity and flow rate of the well fluid were measured; gamma-ray logging, thermoconductive debitometry (determination of the place of inflow into the well), and heterogeneities of the well string and tubing were determined. The actual design of the well and the location of the process well were determined. equipment. Data were obtained showing the filling of the wellbore with fluid, the distribution of fluid density in the study interval, and gas-dynamic parameters. The reservoir pressure calculated according to the HPC data for a depth of 1540 m was Rpl = 9.86 mPa (97.31 atm).

Based on the measurement results, a tablet was built (Fig. 12) and the inflow profile was determined (the graphs corresponding to the studies from 01/07/2011 1 year are presented in the middle column of Fig. 12). When comparing the obtained data with the results of lithology for the potential well flow rate, “working” (highlighted in yellow) and “non-working” intervals were identified within the horizontal part of the wellbore. Flushing of non-working intervals of the well was carried out through coiled tubing, in stages, after 200-300 meters. Based on the results of repeated geophysical surveys, a tablet was built (graphs corresponding to the studies from January 26--28, 1 year, are presented in the last column of Fig. 12), showing the addition of the inflow interval after washing the well using the inventive technology.

Claims

CLAIM

1. A method for recovering the operating state of an oil and gas producing well with horizontal and / or subhorizontal completion during operation, which includes three stages, the first of which delivers geophysical instruments to the well, using which the geophysical parameters of the well are measured, including measurements within the horizontal part of the wellbore wells, which determine the profile of the inflow of the investigated section of the well with the allocation of "idle" intervals, at the second stage, flush about tons of technogenic liquids of the well sections corresponding to the identified “idle” intervals of the inflow profile, at the third stage, control measurements of the geophysical parameters of the well are carried out with the determination of the qualitative and quantitative characteristics of the debit of the sections identified as “non-working” in the first stage.

2. The method according to claim 1., Characterized in that when identifying "idle" sites according to the results of geophysical measurements in accordance with the third stage, the washing of "idle" sites is repeated.

3. The method according to claim 1, characterized in that the following geophysical parameters are measured for determining the inflow profile of the well section under investigation: the natural radioactivity of the near-wellbore rocks, the induced radioactivity of the near-wellbore rocks, the number of coupling joints and other metal structures of the well string and the distance between them, temperature, pressure, current flow rate along the wellbore, percentage of liquid and gas-water-oil components present, specific resistance of the fluid along the wellbore kvazhiny, location of the wellbore, HPC, acoustic noise; the measured parameters determine the actual design of the well and the technical condition of the string, the level of filling the wellbore with fluid in the working and stopped wells, the density of the fluid along the wellbore, reservoir pressure, production rate, annular pressure, bottom-hole pressure, bottom-hole temperature, and working intervals are calculated with the determination of the percentage of total flow rate and quantitative parameters with an interval breakdown, the determination of annular flows, while measured and read parameters are displayed visually on the tablet.

4. The method according to claim 1, characterized in that the delivery of geophysical instruments for measuring the geophysical parameters of the well is carried out using an installation with a first column of flexible tubing, equipped with a geophysical cable located inside the flexible tubing, configured to connect to geophysical instruments, while to prevent deformation of the flexible pipe, the latter is filled with process fluid, and flushing of well sections corresponding to the identified The “idle” intervals of the inflow profile in the bottomhole portion of the horizontal / subhorizontal section of the well are carried out using a second coiled tubing string without cable inside the pipes, configured to connect to the installation with the first coiled tubing string.

5. The method according to p. 3, characterized in that additionally take samples of the well fluid to determine its origin.

6. The method according to claim 4, characterized in that during the delivery of the geophysical equipment the pressure of the process fluid as the coiled tubing is immersed in the well is changed to a value commensurate with the reservoir pressure, while the differential pressure in the string between the coiled tubing and wellhead pressure is maintained in the range values of 90-150 atm depending on the depth of the well.

7. The method according to claim 4, characterized in that as the working fluid use a fluid characterized by a minimum coefficient of thermal expansion, dielectric properties, anticorrosion properties, and not freezing to -60 ° C.

8. The method according to claim 4, characterized in that the transformer oil, diesel fuel, crude oil, or mixtures of these liquids are used as the working fluid.

9. The method according to claim 4, characterized in that for washing the coiled tubing string is lowered to the "idle" section of the well, while first injecting a chemical reagent into the string, which is used as a substance with foaming properties, which reduces the degree of surface tension located in liquid well at least 2 times, and then gaseous nitrogen to ensure the rise from the bottom of the foamed aqueous solution.

10. The method according to claim 9, characterized in that the injected chemical reagent and gaseous nitrogen are taken in a volume corresponding to the volume of filling of the "idle" section of the well before the bottom, the injection rate of the chemical reagent, gaseous nitrogen and the rate of descent of the CT are selected to ensure uniform distribution of the chemical reagent in the idle interval, while the time of the start of the injection of the chemical reagent and gaseous nitrogen into the coiled tubing string is selected depending on the provision of the conditions for the beginning of the output of the chemical reagent from the pipe string when the entrance to the “idle” section of the well is reached, and the beginning of the gaseous nitrogen exit when the bottom of the well is reached, after which the pipe string begins to rise at a minimum speed and continues to pump nitrogen into the bottom-hole zone of the “non-working” section, thereby providing the removal of fluid to the surface of the reservoir.

11. The method according to claim 9, characterized in that the movement of the pipe string along the “idle” section during the injection of the chemical reagent and gaseous nitrogen into the column is carried out at a speed of 3-5 m per minute.

12. Technological complex for the recovery of the operating state of an oil and gas producing well with horizontal and / or subhorizontal completion, including at least two mobile units with coiled tubing connected to wellhead equipment with a flare line in accordance with the technological cycle, one of which is designed for geophysical research and delivery of instruments and tools into the well, and the second for flushing the bottom of the well; as well as a geophysical station with a set of geophysical instruments connected to the first coiled tubing installation, equipment for flushing "idle" sections of the well, the first installation consisting of a coiled tubing drum, injector with a guiding groove (gooseneck), a preventer block, a sealant and a manipulator equipped with a hydraulic drive of an additional high-pressure hydraulic pump to maintain the required pressure of the process fluid in the flexible pipe, When this is placed in a tube coiled cable transmission geophysical data recorded geophysical instruments and geophysical instruments connection with coiled tubing string formed by leaktight transition node - a connector with a special connector - ferrule second installation with a coiled tubing intended for washing the bottom of the well, is a drum with a coiled tubing located on a movable platform, for example, a vehicle platform, configured to connect the first coiled tubing and the flushing equipment to the hydraulic system.

13. The technological complex according to claim 12, characterized in that the equipment for washing the “idle” sections of the well includes a mobile nitrogen unit, which includes transport tanks with liquid nitrogen, a nitrogen convector for converting liquid nitrogen into gaseous, a pumping unit for supplying chemical reagent, a recirculation tank for formation fluid connected to the wellhead through the unit for studying the fluid of the well, as well as a pump unit for loading formation fluid into the transp filling containers for subsequent disposal, while the pumping unit and mobile nitrogen unit are connected via a high pressure manifold through a high pressure manifold to the coiled tubing string of the second coiled tubing unit for flushing the bottom of the well.

14. The technological complex according to claim 12, characterized in that the first and second installations with the coiled tubing string are located parallel and at a distance from each other, ensuring the placement of the flexible pipes of the installations in the injector without dismantling the surface downhole equipment.

15. The technological complex according to claim 12, characterized in that the first and second coiled tubing are located relative to each other with the formation of an angle between their flexible pipes at the point of connection to the wellhead equipment up to 25 °.

16. The technological complex according to claim 12, characterized in that the hydraulic pump of the first coiled tubing installation has an electric drive and is mounted on a subframe in close proximity to the drum with the coiled tubing string and is connected to the drum by a high pressure pipeline.

17. The technological complex according to claim 12, characterized in that the geophysical station is a mobile complex including a geophysical unit, a universal power source for geophysical instruments, a switching unit, an uninterruptible power supply, a plotter.

18. The technological complex according to claim 12, characterized in that the set of instruments for geophysical exploration contains instruments of the PO 50 and SLM brand for recording inhomogeneities of the string and tubing, as well as complex instruments SAT-43GR and PLT-9.2 for carrying out flowometric studies .

19. The technological complex according to claim 12, characterized in that the set of equipment for flushing the well includes a flushing nozzle, a connector used to connect the coiled tubing string to the flushing nozzle, a check valve block that allows fluid and gas to be injected into the well and preventing the flow of well fluid into Coiled tubing, while the flushing nozzle is made with calibrated holes to create a pressure flow of liquid and gas.

20. The technological complex according to p. 12, characterized in that the connector is made with the possibility of filling in the CT and connecting the pipe to the cable lug, while the cable lug is a part of a prefabricated structure with a central through hole for accommodating the cable and includes a sealant connected to the connector, geophysical cable attachment unit, articulated mechanism designed to give flexibility to the cable lug, cable head made with the possibility of connecting the geophysical instrument.

21. The technological complex according to claim 12, characterized in that the connector is capable of refueling in the CT and connecting the pipe to the cable lug, while the cable lug is a part of a prefabricated structure with a central through hole for accommodating the cable and includes a cable adapter connected to the connector , sealant, single-joint mechanism, cable head, made with the possibility of connecting a geophysical instrument.