WO2015034393A1 - System for developing underwater oil or gas field - Google Patents

Abstract

The invention relates to the mineral development industry. A system comprises at least one shaft-module (1), having a central node (2) which is located under water at the ocean floor and which has a vertical shaft which is inserted into the ocean floor, at least one airlock chamber (4, 5) for supplying workers, materials and equipment during duty shifts, at least one drilling site which extends away from the vertical shaft of the central node and includes a horizontal tunnel (6), an inclined portion (7) for supplying drill pipes, and a vertical portion (8), the bottom portion (9) of which encompasses a mouth of at least one well. Connected to the shaft-module are a power cable (10), control systems, and a pipeline (12) which is provided with a protective sheath and is used for transporting oil or gas.

Description

 Subsea oil or gas development system

 The invention relates to the mining industry, and specifically to a system for developing an underwater oil or gas field, mainly in the Arctic and adjacent areas.

State of the art

 A known system for developing an underwater oil or gas field on the Arctic shelf, providing for the initial placement on the ocean floor of a plate having the required number of wells located in accordance with the grid location of the wells on an ice-resistant base. The plate is buried in the ground by the amount necessary to pass an ice-resistant base over the surface of the plate. A self-elevating floating drilling rig is installed above the stove and leading wells are drilled from it through the bottom plate to the required depth. Then the wells are completed and the drilling rig is diverted from the drilling site, where an ice-resistant base is made, made in the form of a fully equipped ice-resistant offshore platform, which is installed above the bottom plate, point it to the plate, combine the wells of the platform and the plate, and then land the platform on soil, form the mouth of the wells on the platform, put the wells into operation on it, and then make further exploitation of the field both in ice-free and in ice periods. The ice-resistant base of the complex has operational, power equipment and a residential block module and is designed as an offshore platform with a recess in the bottom part in the area of the platform’s well network for alignment with the bottom plate when landing the platform (RU 2123088 C1, IPC ЕВВ 17/00, 1998 )

A well-known system of mining in an underwater field, which provides for the installation of a hollow strong metal structure with its subsequent deepening into the seabed along the entire perimeter of the base, and then enclosed inside structures, sea water is removed outside the structure until the bottom is completely exposed, which is drained or frozen and equipped for production needs, including for the purpose of carrying out work on the development of an oil or gas field using traditional ground-based technologies (EA 006717 V 1, IPC E21 C 50 / 00, 2006).

 Other solutions are widely known, involving the use of surface floating or stationary offshore drilling platforms, which, like the solutions described above, have a number of common disadvantages.

 In the event of an accident at a floating drilling rig or at an underwater drilling platform, oil or gas will spill directly into the environment, which will inevitably lead to an environmental disaster. Well-known drilling rigs are operated in extreme conditions of low arctic temperatures, wind and other adverse weather conditions, which creates difficult living conditions for personnel providing the functioning of this equipment. Difficult ice conditions also create problems during the work. When installing and maintaining an underwater drilling system, a large number of underwater operations are required (preparing a horizontal site for installation, installing anchors, supplying communications, etc.), which imposes significant limitations in the cold water of the Arctic.

SUMMARY OF THE INVENTION

The objective of the present invention is to expand the arsenal of tools for the development of subsea oil or gas fields, to ensure environmental safety, create comfortable conditions for staff to work in cold and extremely cold climates, the possibility of work regardless of the ice situation on the ocean surface, the possibility of work on offshore at depths of up to 500 meters and at any distance from the mainland, and with the further development of deep-sea diving techniques deeper. The solution to this problem is provided by the development system of an underwater oil or gas field, which contains:

 - at least one module shaft with a central node located underwater at the bottom of the ocean, having a vertical shaft deepened into the bottom of the ocean and at least one lock chamber for supplying duty shifts of workers, materials and equipment;

 - at least one drilling section extending from the vertical shaft of the central node and comprising a horizontal tunnel, an inclined section for supplying drill pipes, and a vertical section, in the bottom of which is located the mouth of at least one well;

 - a power cable and control systems connected to the mine module and a pipeline with a protective sheath for transporting oil or gas.

 In a preferred embodiment, the lock chamber consists of:

 - upper and lower chambers;

 - the upper horizontal gate separating the upper chamber from the ocean;

 - lower horizontal gates separating the upper and lower chambers;

 - central vertical gates separating the lower chamber from the central node;

 - lifting gear.

The lifting mechanism is located in the upper chamber and contains retractable support elements for locating a pressurized cabin with workers or a container with materials or equipment lowered to the bottom, as well as two opposed nodes of synchronous vertical movement, each with a horizontal movement node with a carriage having two mooring trusses with grips made with the possibility of interaction with a pressurized cabin with workers or with a container with materials or equipment for mounting it on a lifting mechanism.

 Typically, the system comprises at least one drilling rig located at the bottom of the vertical section.

 In the best embodiment of the invention, the module shaft is provided with a second lock chamber.

 The mine module can be equipped with a device for erosion of the soil and pumping the resulting water-soil suspension into the ocean.

 The central unit may include technical passages located under the floor and accessible through hatches, communication channels, as well as a pumping station compartment.

 In a preferred embodiment, the main and emergency pipelines, as well as the pipeline for associated gases connecting the well with the pumping station, are mounted in a horizontal tunnel.

 In a horizontal tunnel, a floor can be mounted that is capable of moving trolleys and emergency tanks located under the floor for collecting spilled oil, waterproof partitions with gates separating the central node and located at intervals along the length of the horizontal tunnel.

 The module shaft may contain an output compartment through which a pipeline for transporting oil or gas is connected to a pumping station.

The implementation of the invention

 The possibility of carrying out the invention is shown in the examples illustrated in the diagrams:

 - figure 1 shows a plan of the shaft module with three drilling sections;

- figure 2 shows the plan of the mine module with three drilling sections, an underground oil storage or gas storage and associated gas storage; - Fig. 3 shows a system for developing an underwater oil or gas field with a module shaft, a drilling section and a system for transporting oil or gas to the mainland, side plan;

 - figure 4 shows a plan of a system for developing an underwater oil or gas field with several module shafts, with several drilling sections each and a system for transporting oil or gas to the mainland;

 - figure 5 shows a cross section of a pipeline for transporting oil or gas with a protective sheath;

 - figure 6 shows a diagram of the construction of the Central node using the bell;

 - Figures 7 and 8 show a plan of a central assembly with two lock chambers, Fig. 7 is a plan view, Fig. 8 is a section along AA in Fig. 7;

 - Fig.9-12 shows the lock chamber, Fig.9 is a top view with the upper horizontal gates closed, Fig.10 is a side view, longitudinally in section, Fig.1 1 is a side view, transversely in section, Fig.12 - top view with open upper horizontal gates;

- Figs. 13-21 are diagrams of the stages of operation of a lock chamber with a pressure chamber, Fig. 13 is a side view of a pressure chamber before installation on a lock chamber, Fig. 14 is a pressure cabin orientation before installation on a lock chamber with an upper horizontal gate open, side view , Fig. 15 is a lock chamber with an open upper horizontal gate and a lifting mechanism prepared for receiving a pressure chamber, side view, Fig. 16 is a lock chamber with a locked cabin locked by a lifting mechanism above the upper horizontal gate, view of glitch ku, FIG. 17 — a lock chamber with a pressurized cabin above the upper horizontal gate at the moment of undocking of the catch of the launching device of the support ship, side view, FIG. 18 - pressurized cabin in the upper chamber of the lock chamber in a fixed position, side view, FIG. 19 - pressure chamber in the upper chamber of the lock chamber before moving to the lower chamber, side view, Fig.20 - the position of Fig. 19, a cross section, Fig. 21 is a pressure chamber in the lower chamber of the airlock, side view;

 - in Fig.22 - 24 shows a diagram of the passage of the horizontal tunnel of the drilling section from the central node, Fig.22, 24 is a side view, Fig.23 is a cross section of a horizontal tunnel;

 - on Fig and 26 shows the waterproof partition of the horizontal tunnel, Fig.25 is a front view, Fig.26 is a top view with a diagram of the opening of a double gate with a door, as well as a door for technical passage;

 - on Fig and 28 shows a waterproof partition of the horizontal tunnel with the location of the plug place provided for pipelines, Fig.25 is a front view, Fig.26 is a top view with a diagram of the opening of a double gate with a door, as well as a door for technical passage;

 - on Fig, 30 shows a diagram of the passage of the horizontal tunnel of the drilling section from the Central node with a mounted concrete floor, Fig.29 is a side view, Fig.30 is a cross section with a view of the double gates of the waterproof partition;

 - Fig.31 shows a diagram of a horizontal tunnel and an inclined section, side view;

 - on Fig and 33 shows a diagram of a horizontal tunnel, an inclined and a vertical section, Fig.32 is a side view, Fig.ZZ is a transverse section along a plane through a horizontal tunnel;

 - Fig.34 shows a diagram of the drilling section at the stage of drilling;

 - Fig. 35 shows a diagram of a drilling section with a vertical section taken out of service;

- Fig.36-38 shows a diagram of the drilling section during the development of an oil field, Fig.36 is a side view with fragments of top views of the beginning and end of the horizontal tunnel, Figs. 37, 38 are transverse sections, respectively, of the beginning and end of the horizontal tunnel; - Fig. 39, 40 shows a diagram of a central node in the development of an oil field; Fig. 39 is a plan view, Fig. 40 is a section along aa in Fig. 39;

 - Figs. 41 and 42 show a waterproof partition separating the horizontal tunnel from the central unit when developing an oil field, Fig. 41 is a front view, Fig. 42 is a plan view of a double gate opening with a door;

 - Figs. 43-45 show a diagram of a drilling section during gas field development, Fig. 43 is a side view with fragments of top views of the beginning and end of a horizontal tunnel, Figs. 44, 45 are cross-sections, respectively, of the beginning and end of a horizontal tunnel;

 - on Fig, 47 shows a diagram of a Central node in the development of a gas field; FIG. 46 is a plan view, FIG. 47 is a section along aa in FIG. 46;

 - Figs. 48 and 49 show a watertight partition separating the horizontal tunnel from the central unit when developing a gas field, Fig. 48 is a front view, Fig. 49 is a plan view of a double gate opening with a door;

 - Fig. 50 shows a diagram of the construction of the output compartment using a bell;

 - on Fig and 52 shows a diagram of the output compartment, side view, Fig.51 - with the location of the partition, Fig.52 - with the location of the power cable and control system and pipeline;

 - on Fig and 54 shows a diagram of the entrance to the output compartment, Fig - front view, Fig - view from above;

 - Fig. 55 shows a diagram of a drilling section with a central unit and a pipeline outlet to the mainland, side view;

 - on Fig shows a diagram of the coastal base of the field.

The structural unit of the development system of an underwater oil or gas field is a mine module 1 (Figs. 1, 2, 3, 4) with several wells. The system may include one or more shaft modules 1. The mine module 1 is located under water at the bottom of the ocean and has a central unit 2, a vertical shaft 3 deepened into the bottom of the ocean (Fig. 3) and two lock chambers 4, 5 for supplying duty shifts of workers (mainly during construction), materials and equipment.

 The system provides for the presence of at least one drilling section extending from the vertical shaft 3 of the central node 2 and including a horizontal tunnel 6, an inclined section 7 for supplying drill pipes (not shown in the diagrams), and a vertical section 8, in which bottom part 9 is located the mouth of at least one well. From the vertical section 8, several wells may be drilled.

 A power cable 10 and a control system and a pipe 12 for transporting oil or gas are connected to the mine module 1.

 Initially, airlock chambers 4,5 are built to supply duty shifts for workers, a tunneling shield, pipes and other equipment. When designing the lock chamber and calculating its strength according to SNiP P-23-81 * and SNiP 2.01.07-85 *, it is necessary to take into account the hydrostatic pressure that will be exerted on it at the calculated depth using the formula p = pgh, where p is the pressure of the liquid layer, Pa; p is the density of the liquid, kg / m; g is the coefficient, N / kg; h is the height of the liquid layer, m

 To minimize underwater work during construction, it is proposed to use a reinforced concrete bell 13 (Fig. 6), which consists of several segments 14.

 Segments 14 of bell 13 are made ashore according to SNiP 2.06.08-87, also taking into account the depth of the ocean at which it will be located. Then, the finished segments 14 of the bell 13 are delivered by sea to the construction site and assembled at the bottom in a single structure.

Transportation of goods is carried out in accordance with the rules of transportation by sea (RD 31.10.10-89). Underwater technical work should be carried out in accordance with SNiP 3.07.02-87 (paragraph 3) and in accordance with RD 31.84.01-90 and RD 39.121.92. The bell 13 has its own lock chamber 15, with which builders and all necessary equipment are lowered into it.

 The supply of electricity and air is carried out using a cable and hose line 16 from the support ship, also in accordance with RD 31.84.01-90 and RD 39.121.92, which are attached to connector 17 on the bell 13.

 Immersion and work in the bell 13 can be carried out, for example, in saturation mode using deck diving equipment. This method is currently gaining ground in various deep-sea operations.

 The organization of the slopes is as follows. Throughout the entire period of work, builders live in a pressure chamber located on a supply vessel (not shown in the diagrams). It maintains a pressure corresponding to the pressure in the bell 13. Before descent, a pressure chamber is joined with the pressure chamber. After establishing a pressure equal to the pressure in the pressure chamber in it, the builders go to the pressure chamber and are delivered to the bell 13. After working the specified time in the bell 13, the builders make the return journey (lifting in the pressure chamber - docking - transition to the pressure chamber) at the same constant pressure gas respiratory mixture. Decompression of builders is carried out only once after the implementation of the planned underwater work. The complex provides in the “saturation” cycle the normal life of builders working in two shifts with a maximum duration of the “saturated” immersion cycle of 29 days. In case of some unforeseen circumstances, a group of builders can be replaced, moreover, one group can work, and the other, replaced, undergo decompression in another pressure chamber.

This diving organization is very effective. It provides a high level of labor productivity, economic profitability of underwater operations and their sufficiently high reliability. Existing deck complexes allow you to work at great depths. In particular, one of the American complexes of this type MK-1 It is used for work at depths of 260-300 m. And complexes are already being used for work at depths of up to 500 m.

 After the construction of lock chambers 4, 5, they begin the construction of the central node 2 (Fig. 7, 8). In it under the floor are placed technical passages 18, which can be accessed through hatches 19 and channels 20 for laying communications. Also, a compartment 21 is being built under the floor for the installation of a pumping station. At the end of the construction of the central node 2, the bell 13 is dismantled, and the cable-cable and hose line 16 are attached to a similar connector 22 (Fig.6) on one of the lock chambers 4, 5.

 Each lock chamber 4, 5 consists of an upper 23 and a lower 24 chambers (FIGS. 10, 11), upper horizontal gates 25 separating the upper chamber 23 from the ocean, and lower gates 26 separating the upper 23 and lower 24 chambers, the central vertical gates 27, separating the lower chamber 24 from the Central node 2, and the lifting mechanism 28, which is located in the upper chamber 23.

 The lifting mechanism 28 (FIGS. 10-12) contains two opposed nodes 29 of synchronous vertical movement with the help of gear wheels 30 (FIG. 12) moving along the rails 31 mounted in the wall, each with a horizontal movement unit along two monorail beams 32 with a carriage 33, having two mooring trusses 34 with grippers 35, made with the possibility of interaction with a pressurized cabin 36 (Fig.13) with workers or with a container with materials or equipment for its fastening on the lifting mechanism 28.

 On the lifting mechanism 28 there are two guides 40 (figure 10,

1 1, 12) along which the rails 41 with the carriage 33 attached to them move. On the carriage 33 there are two mooring trusses 34 and a mast 42 for supplying air and electricity to the pressurized cabin 36. The grips 35 on the mooring farms 34 along the guides 43 (Fig. 10, 12) are moved with the help of rails 44 (Fig. 10) in the frontal plane.

The lifting mechanism 28 operates as follows. When receiving either a pressurized cabin 36 with workers, or a container with materials and equipment (Fig. 13), on which there are attachment points 45 for grippers 35 and connectors 46 and 47, the upper chamber 23 of the lock chamber 4 or 5 is filled with water and the upper horizontal wings open gate 25 (Fig. 14).

 Then, the lifting mechanism 28 along the monorail beams 32 rises to its highest position (Fig. 15). After this, the rails 41 with the carriages 33 along the guides 40 also rise to the highest position and on the carriages 33 the mooring trusses 34 and the mast 42 are opened. The lower parts 48 of the rails 41 (Figs. 10, 11, 12) are folded at an angle of 90 ° , serve as removable support elements for a pressurized cabin 36 with workers or a container with materials or equipment.

 The operator of the launching and launching device (SPU) of the support ship (not shown in the diagrams), bringing the pressure cabin 36 or container to the lock chamber 4 or 5, receiving data from the spatial sensors and checking the beacons on the lock chambers 4 or 5 with the help of video cameras under illumination projectors (not shown in the diagrams) located on the sides of the pressurized cabin 36, expose it in the correct position relative to the lock chamber 4 or 5 and place it on the lower parts of the 48 rails 41, after which the operator of the lock chamber 4, 5 (the lock can be controlled as with a check you, and from the support ship) closes the mooring farms 34, fixing the pressurized cabin 36 or the container using the grippers 35 located on them.

 The efforts of the mooring trusses 34 are enough to, if necessary, slightly move the pressurized cabin 36 or the container in the horizontal direction for full capture by all attachment points 45 for grips 35.

Then the operator dockes the support mast 42 to the connector 46 (Fig. 17). Connector 46 is located on the roof of the pressurized cabin 36 so that in the event of a failure of the main hose line or power cable, an emergency can be connected to it from the ship. Having made sure with the help of cameras illuminated by searchlights, and having received data from the sensors, that the container is securely fixed by all grips 35, the operator undocks the SPU grip 49 from it (Fig. 17) (the SPU operator cannot disconnect the grip 49 from the pressurized cabin 36 on its own to avoid accidents). Capture 49 can only be undocked by joining connector 46. In an emergency, the operator of the control system can do this from a stand-alone emergency console by breaking the protective glass. The movement of the lifting mechanism 28 will also be blocked until the capture 49 SPU is undocked. After undocking the capture 49 SPU, the gateway operator lowers the pressurized cabin 36 in the upper chamber 23 (Fig. 18).

 The upper horizontal gates 25 of the lock chamber 4 or 5 are closed and all water is pumped out of the upper chamber 23, the lower horizontal gates 26 are opened (Fig. 19), the lower parts of the 48 rails 41 are opened (Figs. 19, 20). And the rails 41 together with the carriages 33 and the hermetic cabin 36 fixed in them along the guides 40 are lowered into the lower chamber 24 (Fig. 21). Next, the carriages 33 along the rails 41 (Fig. 21) are lowered down and a pressure cabin 36 or a container is placed, respectively, on the floor or platform of the trolley.

 The pressurized cabin 36 or the container is removed from the lock chamber 4 or 5 in the reverse order. When the pressurized cabin 36 is at the top, the SPU operator, under the control of the video camera located on the SPU capture 49, using the thrusting screws, brings the 49 capture to the 36 pressurized cabin and joins the connector 47. Having made sure that the connection with the video camera and the sensor readings are reliable, the SPU operator opens the 35 mooring grips farms 34 and diverts the mooring farms 34, and then the supply mast 42. After using the video cameras to illuminate the spotlights located on the sides of the pressurized cabin 36, making sure that the mooring farms 34 and the supply mast 42 are moved away from nothing interferes with the lift, the operator of the control system proceeds with the lifting of the pressurized cabin 36 or container to the support ship.

The descent or ascent of the pressurized cabin 36 or container may be carried out automatically under the control of the operator. The lock chamber 15 of the bell 13 works in a similar way, but smaller in size.

 Instead of two identical lock chambers 4, 5, lock chambers 4, 5 of different designs can be used, only one of which is suitable for accepting a pressurized cabin 36 or a container with goods. Two lock chambers 4, 5 are provided for safety and maintenance reasons. If one of the lock chambers 4 or 5 breaks down, it will be possible to get into the mine with the help of another. Lock chambers 4, 5 - this is the only connection between the shaft module 1 with the outside world.

 Given that the lock cameras 4, 5 operate in an aggressive environment

(sea water), from time to time they will need to carry out various preventive maintenance and periodically replace the mechanisms that have developed their resource, because the lock chambers 4, 5 will work for more than one year. And when one lock chamber 4 or 5 will be on the preventive maintenance, it will be possible to get into the mine with the help of another. Also, using a working lock chamber 4 or 5, it is possible to supply spare parts for another repaired or maintained lock chamber to the module shaft 1.

 After the construction of lock chambers 4,5 and the central node 2 is completed, they begin laying a horizontal tunnel 6, inclined 7 and vertical 8 sections. The horizontal tunnel 6 (Fig. 22) is constructed using a tunnel shield 50 (for example, a collapsible shield with a closed head part d 6000). Excavation work is carried out in accordance with SNiP 32-04-97.

The produced soil can be removed from the mine in various ways, for example, trolleys 51 are delivered from the tunneling shield 50 to the reservoir (not shown in the diagrams), where the soil is washed out and thrown out using a pump (e.g. NS) through an extension pipe. The rocky soil or sediment remaining after washing out in the form of stones and other indelible rock is loaded into containers and lifted either to a service ship, or with the help of SPU, the container is removed from the lock chamber and unloaded next to the module shaft 1 at the bottom of the ocean. The length of the horizontal tunnel 6 can be any. Concrete half rings 52 intended for facing the horizontal tunnel 6 must have special hydrostatic connections according to SNiP 32-04-97, since seawater can leak out through cracks in the ground.

 At the beginning of the horizontal tunnel 6, a waterproof partition 53 is mounted (Figs. 24, 25, 26) having a double gate 54 with a door 55, as well as a door 56 for a technical passage. Further, throughout the horizontal tunnel 6 at a certain distance (for example, every 200 meters), waterproof partitions 57 (Figs. 27, 28) are also mounted, which differ from the waterproof partition 53 by the presence of a metal plug 58 for laying pipelines. Further in the compartments mounted partitions 60, (Fig. 29, 30), separating the technical passage 18 from the emergency tanks 61, if it is a mine for oil production. Emergency tanks 61 are connected by a jumper 62. Then the concrete floor 59 is mounted. The concrete floor 59 has hatches 19, through which from the technical passage 18 you can enter any part of the horizontal tunnel 6, drainage hatches 63 (Fig. 36) to drain spilled oil into emergency containers 61 and rails for trolleys 64. As the horizontal section 6 is built and the floor 59 is installed to drive onto it from the horizontal section 6 under construction, 51 trolleys 51 at the end of the section with already installed floor 59, a temporary overpass 65 is built. ontazha next concrete floor portion 59 is dismantled and transported further. At the end of the construction of the horizontal tunnel 6, overpass 65 is disassembled and exported. In the technical passage 18, all the necessary communications 66 are mounted (power cable and control systems 10, cables and lighting shades, gas analyzers, etc.) (Fig. 30).

A horizontal tunnel 6 is laid to the drilling site. Then the crane beam 67 is mounted (Fig. 31), with the help of which vertical penetration is carried out. Initially, an inclined section 7 is constructed for supplying pipes and then the vertical section 8. At the end the construction of the vertical section 8 (Fig. 32) on its bottom part 9 is a drilling rig 68, a warehouse of pipes 69, a station for preparing working mixtures 70 and other auxiliary equipment 71. Cartridges 72 with pipes are delivered to the drilling site using special trolleys 73 (Fig. . 33). Moving cartridges 72 with pipes and other materials in the vertical section 8 is carried out using a crane beam 67.

 For drilling, the use of a compact drilling rig is most preferred. Using the same directional drilling method allows drilling from a single vertical section 8 of several tens of wells 74 in different directions (Fig. 34).

 Drilling is carried out remotely, without the participation of people, from the mainland - from the control center 75 (Fig. 56) or from the support vessel.

 In case of unsuccessful (dry) drilling, the well is jammed, the vertical section 8 is filled with soil to a horizontal level and the horizontal tunnel 6 continues to the next drilling site (Fig. 35). This minimizes costs.

 In case of successful drilling, pumping equipment is mounted (Fig. 36, 37, 38). A technical passage 18 is installed in the vertical section 8 and inclined section 7. A cascade of valves 76 is mounted on the well. Then, the main 77 and emergency 78 pipelines and the associated gas pipe 74 are laid on the racks 59. At the end of the horizontal section 10 at the entrance to the central node 3 behind the partition 52 is also installed valve 80 on the main 75 and valve 81 on the emergency pipelines 76. An emergency pump is installed on the emergency pipeline. Outlets 83 are lowered from the emergency pipeline 78 to the emergency tanks 61 for pumping the collected oil from them. Pipelines 77 and 79 from the horizontal tunnel 6 are laid through the central node 2 through the channels 20 for laying communications (Fig. 39, 40) to the separation of the pumping station 21.

In the mine module 1 for gas production mounted equipment for pumping gas (Fig. 43, 44, 45). In the vertical section 8 and inclined Section 7 establishes a technical passage 18. A cascade of valves 76 is mounted on the well. Then, main 77 and emergency 78 pipelines are laid on the racks on the racks. A ventilation duct 84 is mounted on the ceiling. At the end of the horizontal tunnel 6, at the entrance to the central node 2, behind the partition 57, a valve 80 is also installed on the main 77 and valve 81 on the emergency pipeline 78. A pumping pump 82 is installed on the emergency pipeline 78. The main pipeline 77 from the horizontal tunnel 6 is laid through the central node 2 through the channels 20 for laying communications (Fig. 46, 47) to the compartment 21 of the pumping station.

 At the final stage of construction, an output compartment 85 is constructed, for example, at an angle of 45 ° (Figs. 50, 51, 52, 55), through which power cables and control systems 10 and pipeline 12 are fed into the module shaft 1. This happens as follows. First, using the bell 13, the output compartment 85 is built (Fig. 50). At the junction of the compartment 85 with the Central node 2, a partition 86 is installed (Fig. 51, 52, 53, 54). It contains: a door 56, a drainage system 87 for pumping water from the compartment 85, closed by a protective casing 88, a plug 89 holes for the pipeline and a plug 90 holes for power and control cables. At the end of construction, the bell 13 is dismantled, and the output compartment 85 is left open (Fig. 51). Then pipes and cables are started in it (Fig. 52). Then, the entry point into the compartment 91 (Fig. 52) is sealed, for example, with the help of two plates with half-openings, and sealed. After sealing compartment 85, builders using a drainage system 87 pump water out of it.

 After the output compartment 85 is built and all communications and pipes are brought to the branch of the pumping station 21, the pumping station itself is mounted.

 There are other ways of laying pipes, for example, under the floor or on the wall.

From the module shafts 1, oil and gas can be transported in two ways: 1. Through pipelines 12, oil and gas are transported to the mainland (figures 1, 3, 4);

 2. The shipment of oil or gas from the mine modules 1 is carried out using remote berthing devices 92 (Fig. 2), for example, type CALM, SALM, SAL to tankers. In the Arctic, pop-up berths of the SAL type are most preferred. When shipped from remote berthing facilities 92, oil or gas is first pumped into the underground oil storage or gas storage 93, and associated gas is extracted to the tankers when oil is extracted into the underground gas storage 94, and then, using the pop-up shipping system 92. At the same time, two additional tunnels 95 should be laid to the storages using tunnel shields.

 An important problem when working on the Arctic shelf is the withdrawal of communications from the sea to land, since in shallow water hummocks and icebergs are very likely to damage them. To solve this problem, with the help of tunneling shields, several output shafts 96 (Figs. 3, 4, 56) can be drilled from land to the deep sea, and all pipes and cables can be passed through them.

Pipes 12 are put on land, for example, as follows - a cable from land is passed through output shafts 96 and fed to the ship by a pipe layer. Then, as the pipes are welded, they are pulled by ropes into the output shafts 96 to a level just above the water level. Then, they are laid along a dry mine to the pumping station 97. Or, for example, they are pulled into the output compartments of the shafts 98 (Fig. 3), which are then sealed similarly to the sealing of the output compartments 85 of the mine-module 1, after which water and pipes are pumped out of the output compartments of the mines 98 in a dry mine, they are laid to the shore, to the pumping station 97. Further, oil or gas is transported via the land pipeline systems 100. The power and control cables 10 can be discharged into the sea in a similar way. During the field’s operation in the event of an accident in a module-1 mine, the automation shuts off the shut-off valves 76 and 80 and stops the flow of oil or gas to the main pipeline.

 Then, in the mine module 1 for oil production, the shut-off valve 81 on the emergency pipeline opens and with the help of the pump 82 the oil is pumped out of the emergency tanks 61 into the main pipe 77, above the shut-off valve 80.

 In the case of a breakthrough of the pipeline 77, since the vertical tunnel 6 with the help of partitions 57 (Fig. 41, 42) is divided into compartments and separated from the central node 2 by a partition 53 (Fig. 25), the oil will not spill over the entire mine module 1, but will only in one compartment of one horizontal tunnel 6. Doors 55 in double gates 54 are also double, each opens inside its compartment (Fig. 41, 42, 25).

 In the gas shaft, gas is squeezed out of the shaft-module 1 by the air supplied through the ventilation duct 84 and is pumped out through the emergency pipe 78 using the pump 82. Similarly to the above, due to the waterproof partitions 57 (Fig. 48, 49), in the event of an accident, gas does not spread throughout the mine module 1, and will only be in one compartment of one horizontal tunnel 6.

 This will minimize the loss of oil or gas during an accident and prevent them from entering the environment.

 After oil or gas is pumped out, emergency crews begin to eliminate the breakthrough.

 The emergency team is delivered to the module as follows.

The support ship, going up to the module, is docked with a cable and hose line 16 to the connector 22 of the lock chamber 4 or 5 and blows the module shaft 1 with fresh air, after which the emergency crew descends through the lock chamber 4 or 5 into the module shaft 1 and proceeds to eliminate the accident. Also, from the support ship, all the necessary tools and materials are fed into the mine module 1. Along the horizontal tunnel 6, spare pipes and necessary materials are transported using trolleys. In the event of automation failure, the emergency team can reach the cascade of valves 76 and valve 80 through the technical passages 18 and close them manually.

 At the coastal base of the field, in addition to the dispatch center

75, there are also: a transfer station 97, a household sector 99 for resting a work shift, and a helipad 101. The control center 75 is connected to the domestic sector 99 by a covered gallery 102.

 When carrying out large projects on the Arctic shelf, it is necessary to take into account the absence of any infrastructure there, which is a very important problem, and therefore ice-breaking floating nuclear power plants 103 can be used to provide electric power to the field. By mooring several such power plants 103 in sheltered harbor 104 and connecting them with submarine cables through lead shafts 96 with module shafts 1, the energy supply problem can be completely solved.

Personnel: people in the field during construction, and then during its operation, work on a rotational basis. The shift is delivered to the place of work by a support ship accompanied by an icebreaker. Builders work in the mine module 1 in shifts. People descend through the lock chamber 4, 5 into the module-shaft 1, as mentioned above, only for one shift, after which they again climb onto the ship, and a new shift is lowered into the module-1 shaft. The ship serves as a base for rest and maintenance for the duration of the shift , it is fed into the mine module 1 air and electricity. At the end of the shift, when the second support ship with a new shift approaches the module, the ship with the old watch is undocked from the mine shaft of module 1 and returned to the home port, and the newly arrived support ship, etc. takes its place. Personnel also arrive at the shore base of the field on a rotational basis on a support ship, accompanied by an icebreaker. For emergency cases, the base has a helipad 101. The development system of an underwater oil or gas field in accordance with the invention avoids the disadvantages of the known technologies (stationary and floating platforms, underwater drilling and injection systems, etc.). Mine drilling for oil and gas production takes place in a confined space and in the event of an accident, oil or gas does not spill outside the module shaft, and the oil spilled in the mine module or the gas filling it will be collected and pumped out using the emergency systems provided. The system allows equipment and people to work in relatively comfortable conditions, since a constant positive temperature is maintained inside the module shaft. The work can be carried out regardless of ice and hydrometeorological conditions, since the main work takes place underground, under the seabed and does not require any work on the surface of the ocean. The system allows oil and gas to be produced on the sea shelf at depths of the ocean of up to 500 meters and at any distance from the mainland, and with the further development of deep-sea diving techniques and at greater depths.

 Thus, the development of an underwater oil or gas field by the mine method described above, compared with other known drilling methods, is the most preferable option in the Arctic and has several advantages both from an economic and technological, as well as from an environmental point of view. The examples of the invention are not exhaustive. Other options for the practical implementation of the invention are possible, which will correspond to the scope of patent rights.

Claims

Claim

1. The development system of an underwater oil or gas field, containing,

 at least one module shaft with a central node located underwater on the ocean floor, having a vertical shaft deepened into the ocean floor and at least one lock chamber for supplying duty shifts of workers, materials and equipment,

 at least one drilling section extending from the vertical shaft of the central node and comprising a horizontal tunnel, an inclined section for supplying drill pipes and a vertical section, in the bottom of which there is at least one wellhead,

 as well as a power cable and control systems connected to the mine module and a pipeline with a protective sheath for transporting oil or gas.

2. The system according to claim 1, characterized in that the lock chamber consists of upper and lower chambers,

 the upper horizontal gates separating the upper chamber from the ocean,

 lower horizontal gates separating the upper and lower chambers,

 central vertical gates separating the lower chamber from the central node,

 lifting gear

 which is located in the upper chamber and contains removable support elements for the location of a pressure chamber with workers or a container with materials or equipment lowered to the bottom,

as well as two opposite opposed nodes of synchronous vertical movement, each with a horizontal movement node with a carriage having two mooring trusses with grips made with the possibility of interaction with a pressurized cabin with workers or a container with materials or equipment for mounting it on a lifting mechanism.

3. The system according to claim 2, characterized in that it contains at least one drilling rig located at the bottom of the vertical section.

4. The system according to any one of paragraphs 1 to 3, characterized in that the mine module is equipped with a second lock chamber.

5. The system according to claim 4, characterized in that the mine module is equipped with a device for erosion of the soil and pumping the resulting water-soil suspension into the ocean.

6. The system according to claim 5, characterized in that the central node includes located under the floor and accessible through the hatches technical passages, communication channels, as well as the separation of the pumping station.

7. The system according to claim 6, characterized in that in the horizontal tunnel the main and emergency pipelines are mounted, as well as a pipeline for associated gases connecting the well with the pumping station.

8. The system according to claim 7, characterized in that the horizontal tunnel has a floor mounted to move the trolleys and overpass for their movement from the vertical section to the horizontal tunnel floor, emergency tanks located under the floor for collecting spilled oil, waterproof partitions with gates separating the central node and located at intervals along the length of the horizontal tunnel.

 9. The system of claim 8, wherein the module shaft comprises an output compartment through which a pipeline for transporting oil or gas is connected to a pumping station.