Installation device and installation method for deepwater surface pipes

Abstract

The present invention provides a deepwater surface conduit installation device and installation method, the deepwater surface conduit installation device comprises: a surface conduit, a thruster, a lowering mechanism and a conduit base plate; the thruster is installed on the surface conduit, and is used to apply a downward thrust to the surface conduit; the lowering mechanism is used to lower the surface conduit from the sea surface to the seabed; the conduit base plate can be fixed on the seabed, and the conduit base plate is used to straighten the surface conduit. Through the present invention, the technical problems of long operation time and high operation cost in installing a surface conduit in a shallow stratum in deep water are alleviated.

Description

Technical Field

[0001] The invention relates to the field of marine oil and gas development, and in particular to an installation device and an installation method for a deep-water surface conduit. Background Art

[0002] In the exploration of marine oil and gas resources, the surface conduit is the first layer of structural pipe inserted during the construction of deepwater oil and gas wells. It provides structural support for the underwater wellhead, underwater blowout preventer group and oil production tree. The surface conduit must be able to withstand the drilling equipment, casing suspension and various loads loaded on it during future production operations.

[0003] The installation of surface conduits is an important part of deepwater drilling operations. At present, the main methods of lowering surface conduits are hammering, drilling and jetting. For deepwater shallow strata, due to the poor lithology and low stratum strength, the jetting method is often used for underwater installation of surface conduits. During the deepwater jetting installation process, the hydraulic jetting causes a large disturbance to the seabed soil, resulting in a large loss of bearing capacity of the deepwater surface conduit, resulting in a greater risk of sinking or instability of the underwater wellhead. In order to increase the bearing capacity, it is usually necessary to increase the lowering depth or static time of the deepwater surface conduit to reduce the operational risk. However, this will prolong the operation time, increase the operation cost, and increase the operation fee. Summary of the invention

[0004] The purpose of the present invention is to provide a deepwater surface conduit installation device and installation method to alleviate the technical problems of long operation time and high operation cost in installing the surface conduit in the shallow strata of deepwater.

[0005] The above-mentioned purpose of the present invention can be achieved by adopting the following technical solutions:

[0006] The invention provides an installation device for a deepwater surface conduit, comprising: a surface conduit, a thruster, a lowering mechanism and a conduit base plate; the thruster is installed on the surface conduit and is used to apply a downward thrust to the surface conduit; the lowering mechanism is used to lower the surface conduit from the sea surface to the seabed; the conduit base plate can be fixed on the seabed, and the conduit base plate is used to straighten the surface conduit.

[0007] In a preferred embodiment, the installation device includes at least three propellers, which are installed on the outer side of the upper end of the surface catheter, and at least three propellers are distributed circumferentially around the axis of the surface catheter.

[0008] In a preferred embodiment, the thruster includes a combustion power mechanism, a filling chamber and a redundant chamber, wherein the filling chamber and the redundant chamber are both connected to the combustion power mechanism, the filling chamber is used to provide fuel to the combustion power mechanism, and the redundant chamber is used to provide fuel to the combustion power mechanism after the fuel in the filling chamber is exhausted.

[0009] In a preferred embodiment, the redundant bin is connected to the combustion power mechanism through the filler chamber, and a valve is provided between the redundant bin and the filler chamber.

[0010] In a preferred embodiment, the lower end of the surface conduit is configured to be closed.

[0011] In a preferred embodiment, a conical portion is provided at the lower end of the surface conduit.

[0012] In a preferred embodiment, a plurality of circumferentially distributed inclination sensors are provided on the surface conduit, and / or a level is provided on the upper end surface of the surface conduit.

[0013] In a preferred embodiment, the lowering mechanism includes a suspension cable and a release buckle connected to the suspension cable, the upper end of the suspension cable is connected to an operating vessel or a drilling platform on the water surface, and the lower end of the suspension cable is connected to the surface conduit.

[0014] In a preferred embodiment, the catheter base is provided with at least one central hole, and the surface catheter can be inserted into the central hole.

[0015] The present invention provides a method for installing a deep-water surface conduit, using the above-mentioned deep-water surface conduit installation device, the installation method comprising:

[0016] Step S10, fixing the catheter base plate to the seabed;

[0017] Step S20, lowering the surface conduit to the seabed;

[0018] Step S30, starting the propeller, the propeller generates thrust to drive the surface pipe downward into the seabed soil.

[0019] The characteristics and advantages of the present invention are:

[0020] The guide tube base is lowered to the seabed and fixed; the lowering mechanism lowers the surface guide tube to the seabed, and the surface guide tube is kept in a vertical state under the straightening effect of the guide tube base; the thruster is started to apply a downward thrust to the surface guide tube, and the surface guide tube is forced to move toward the seabed soil, completing the installation of the surface guide tube. The installation device uses the boosting effect of the thruster to vertically lower the surface guide tube to a certain depth below the mud line, realizing the installation of the surface guide tube by pushing, which has the following advantages: (1) convenient operation, shortening working time and reducing operation costs; (2) conducive to ensuring the quality of surface guide tube installation and reducing the risk of deep-water operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 A schematic diagram of the structure of the installation device of the deep-water surface conduit provided by the present invention;

[0023] Figure 2 for Figure 1 A top view of the surface conduit in the illustrated installation;

[0024] Figure 3 for Figure 1 A schematic diagram of the connection between the surface conduit, the lowering mechanism and the conduit base plate in the installation device shown;

[0025] Figure 4 for Figure 1 A schematic diagram of the structure of the propeller in the installation device shown;

[0026] Figure 5 A schematic structural diagram of the method for installing a deepwater surface conduit provided by the present invention.

[0027] Description of Figure Numbers:

[0028] 10. Surface conduit; 101. Short section; 11. Conical section;

[0029] 20. Lowering mechanism; 21. Lifting cable; 22. Release buckle; 23. Working boat;

[0030] 30. catheter base plate; 31. center hole;

[0031] 40. Thruster;

[0032] 41. Combustion power mechanism; 411. Nozzle; 412. Engine; 413. Oxidant chamber; 414. Combustion chamber;

[0033] 42. Redundant bin; 43. Filling chamber;

[0034] 44. control box; 441. control button; 45. flow valve; 46. thruster housing;

[0035] 51. Tilt sensor; 52. Level;

[0036] 60. Remote controlled unmanned submersible; 70. Soil. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Embodiment 1

[0039] The present invention provides a deep water surface conduit installation device, such as Figure 1-Figure 3 As shown, the installation device includes: a surface conduit 10, a thruster 40, a lowering mechanism 20 and a conduit base plate 30; the thruster 40 is installed on the surface conduit 10, and is used to apply a downward thrust to the surface conduit 10; the lowering mechanism 20 is used to lower the surface conduit 10 from the sea surface to the seabed; the conduit base plate 30 can be fixed on the seabed, and the conduit base plate 30 is used to straighten the surface conduit 10.

[0040] The guide tube base plate 30 is lowered to the seabed and fixed; the lowering mechanism 20 lowers the surface guide tube 10 to the seabed, and the surface guide tube 10 is kept in a vertical state under the straightening effect of the guide tube base plate 30; the propeller 40 is started to apply a downward thrust to the surface guide tube 10, and the surface guide tube 10 is forced to move toward the seabed soil 70, completing the installation of the surface guide tube 10. The installation device uses the boosting effect of the propeller 40 to vertically lower the surface guide tube 10 to a certain depth below the mud line, and realizes the installation of the surface guide tube 10 by pushing, which has the following advantages: (1) convenient operation, shortened working time, and reduced operation costs; (2) conducive to ensuring the quality of the installation of the surface guide tube 10 and reducing the risk of deep-water operations.

[0041] The propeller 40 provides power for the lowering of the surface catheter 10. The propeller 40 can be set on the outer side of the upper part of the surface catheter 10. When the surface catheter 10 is lowered to a certain distance below the mud surface by its own weight and is blocked and no longer sinks, the propeller 40 is started, and the huge energy generated in the chamber pushes the surface catheter 10 to continue to be lowered.

[0042] In one embodiment, the installation device includes at least three thrusters 40, which are installed on the outer side of the upper end of the surface catheter 10, and at least three thrusters 40 are distributed circumferentially around the axis of the surface catheter 10. When the catheter is tilted during the lowering process, the energy of the thrusters 40 at the corresponding position can be appropriately adjusted to adjust the lowering direction of the surface catheter 10 so that the surface catheter 10 can be kept vertically lowered. Preferably, the thrusters 40 are evenly distributed in the circumferential direction, such as Figure 2As shown, the three thrusters 40 apply thrust to the surface conduit 10 at different positions, which is conducive to balanced thrust distribution, convenient for adjusting the direction of the surface conduit 10, and can effectively control the deviation problem during the lowering process, and avoid the situation where the surface conduit 10 is not lowered into place. The three thrusters 40 are evenly installed on the outer wall of the top of the surface conduit 10. Specifically, the thrusters 40 are arranged on the outer top of the uppermost short section 101 of the surface conduit 10, and can be fixed by welding. During production and processing, the thrusters 40 are welded to the short section 101 at the top of the surface conduit 10; the short section 101 is welded to the thrusters 40 during factory processing, and the short sections 101 can be connected by welding or threading.

[0043] The thruster 40 contains fuel and oxidizer, which generate huge energy when burned, providing driving force for the lowering of the surface conduit 10. According to the calculation of the depth of entry into the mud, an appropriate amount of fuel and oxidizer are loaded into the thruster 40 to ensure that the thrust provided can deliver the surface conduit 10 to the specified position. First, the friction profile between the surface conduit 10 and the seabed soil is calculated, and then the thruster 40 is loaded with the corresponding amount of fuel and oxidizer. After the surface conduit 10 is lowered to the conduit base plate 30, the thruster 40 is started, and the huge thrust generated by the fuel in the thruster 40 provides sufficient power for the subsequent lowering of the surface conduit 10.

[0044] like Figure 4 As shown, the propeller 40 includes a combustion power mechanism 41 and a filler chamber 43. Figure 4 As shown, the combustion power mechanism 41 includes a nozzle 411, an engine 412, a combustion chamber 414 and an oxidant chamber 413. The thruster 40 also includes a thruster housing 46. A control box 44 is provided outside the thruster 40, which contains a plurality of control buttons 441. The ROV (Remote Operated Vehicle, remote unmanned submersible 60) can be used to control and adjust the start of the thruster 40 and the flow of each chamber. The valves of the packing chamber 43 and the oxidant chamber 413 are opened to allow the fuel and the oxidant to burn in the combustion chamber 414, driving the engine 412, and the engine 412 provides the power for the surface catheter 10 to be lowered. When the surface catheter 10 tilts during the lowering process, the flow can be adjusted by the control buttons 441 outside each thruster 40. At this time, the energy generated in the combustion chamber 414 of each thruster 40 is different, and the thrust at each position also changes accordingly, thereby rebalancing the lowering process of the surface catheter 10.

[0045] Furthermore, the thruster 40 also includes a redundant chamber 42, and the packing chamber 43 and the redundant chamber 42 are both connected to the combustion power mechanism 41. The packing chamber 43 is used to provide fuel to the combustion power mechanism 41, and the redundant chamber 42 is used to provide fuel to the combustion power mechanism 41 after the fuel in the packing chamber 43 is exhausted. If there is a calculation error or inaccurate prediction, when the predicted consumption of fuel is exhausted, the redundant chamber 42 channel is opened, and the redundant packing is put into use to ensure that the surface catheter 10 is delivered to the designated position. Through the redundant chamber 42, the surface catheter 10 continues to be powered, which can prevent the situation where the seabed soil is complex and the lowering is difficult, resulting in insufficient fuel, so as to ensure that the surface catheter 10 is inserted into the mud to the designed position.

[0046] Furthermore, the redundant chamber 42 is connected to the combustion power mechanism 41 through the packing chamber 43, and a valve is provided between the redundant chamber 42 and the packing chamber 43. The valve may be a flow valve 45. Figure 4 As shown, the filler chamber 43 is connected to the combustion chamber 414 via a flow valve 45, and the oxidant is connected to the combustion chamber 414 via a flow valve 45. Each flow valve 45 can be controlled and adjusted using an ROV.

[0047] In one embodiment of the present invention, the lower end of the surface conduit 10 is set to be closed to prevent the lower soil from entering the surface conduit 10 and to prevent the formation of soil plugs inside the surface conduit 10, so as to reduce the side wall friction during lowering and reduce the soil resistance during lowering and installation. The lower end of the surface conduit 10 is a drillable material, so that the drill bit can drill through the lower end of the surface conduit 10 to facilitate the secondary drilling operation.

[0048] In one embodiment of the present invention, the lower end of the surface conduit 10 is provided with a conical portion 11, such as Figure 1 and Figure 3 As shown, the conical portion 11 is conical, which can increase the breaking stress, increase the breaking capacity, reduce the side wall friction during lowering, reduce the soil resistance during lowering and installation, and make it easier to lower the surface conduit 10. The surface conduit 10 can be a pipe column with a diameter of 36 inches or 30 inches and a wall thickness of 1 inch or 1.5 inches.

[0049] The installation device includes a control room located on the work boat 23 or the drilling platform. The control room can control the installation of the surface conduit 10. Through the control system, the operation personnel can control and adjust the energy and propulsion angle of the propeller 40 according to the depth and inclination angle of the surface conduit 10, so as to ensure the smooth installation of the surface conduit 10. In one embodiment, a plurality of inclination sensors 51 are arranged on the surface conduit 10, and the plurality of inclination sensors 51 are distributed in a circumference, such as Figure 2As shown, the inclination sensor 51 can be arranged on the inner wall of the surface conduit 10. The inclination sensor 51 can capture the angle of inclination that occurs during the lowering of the surface conduit 10, so as to make adjustments in the subsequent operation process. The inclination sensor 51 can adopt a high-precision digital output type inclination sensor 51, with a built-in high-precision A / D conversion chip, and finally output the inclination value through the Kalman n-order filter algorithm and the transformation of the algorithm. The state of the surface conduit 10 is captured through the inclination sensor 51, and the signal is transmitted to the surface control room to provide data for subsequent work adjustments. The operation control room can issue subsequent instructions based on the feedback of the sensor. Preferably, three inclination sensors 51 are included, and the three inclination sensors 51 are evenly arranged on the inner wall of the surface conduit 10 along the circumferential direction.

[0050] In one embodiment, a level 52 is provided on the upper end surface of the surface catheter 10 for observing the tilt state of the catheter during the lowering process. During the lowering process of the surface catheter 10, the level 52 can be used as an auxiliary tool to observe the lowering process of the surface catheter 10, and the ROV can assist in observing whether the surface catheter 10 is offset. The level 52 can be fixed by welding. The three inclination sensors 51 arranged on the inner wall of the surface catheter 10 and the level 52 at the top of the surface catheter 10 can play a role in dual monitoring the tilt state of the surface catheter 10 during the lowering process; the level 52 at the top, the inclination sensor 51 in the middle and the catheter base plate 30 at the bottom constitute a multi-stage anti-tilt device to ensure that the surface catheter 10 is lowered vertically.

[0051] In one embodiment, the lowering mechanism 20 includes a suspension cable 21 and a release buckle 22 connected to the suspension cable 21. The upper end of the suspension cable 21 is connected to a working ship 23 or a drilling platform on the water surface, and the lower end of the suspension cable 21 is connected to the surface conduit 10. During the lowering of the surface conduit 10, the release buckle 22 will automatically disconnect when the tension exceeds the limit tension, so as to avoid affecting the equipment on the water surface. For example, the limit tension of the release buckle 22 is 100 tons. When an emergency occurs and the release buckle 22 is subjected to a tension exceeding 100 tons, the release buckle 22 will automatically release, and the surface conduit 10 will be disconnected from the water surface, so as to avoid dragging the equipment on the water surface and causing greater losses. One end of the suspension cable 21 is connected to the assembled surface conduit 10, and the other end is connected to the crane and winch on the working ship 23 or the drilling platform on the water surface, and the suspension cable 21 is slowly lowered to allow the surface conduit 10 to enter the water. The suspension cable 21 can be an umbilical cable, which is connected to the top of the surface conduit 10, can bear weight, and can complete the installation of the surface conduit 10 from the sea surface to the seabed. At the same time, the umbilical cable contains a signal transmission line for signal transmission. The signal transmission line can be an optical cable, which can transmit signals such as depth and inclination to the control room, and can also transmit control signals to devices such as the thruster 40.

[0052] When the surface conduit 10 is lowered to the bottom of the seabed, the ROV assists in docking with the underwater conduit base 30. The surface conduit 10 is lowered to the mud surface through the suspension cable 21 and is straightened by the conduit base 30. The conduit base 30 can ensure that the surface conduit 10 is vertically lowered, ensuring the verticality of the surface conduit 10. The conduit base 30 can be directly connected to the ship's crane, stern A-frame or winch through a steel wire rope, and slowly lowered to the seabed. The ROV assists in the installation to ensure that it is installed at the design coordinates.

[0053] In one embodiment, the catheter base plate 30 is provided with at least one central hole 31, and the surface catheter 10 can be inserted into the central hole 31, and the central hole 31 can guide the movement of the surface catheter 10. The catheter base plate 30 is provided with multiple central holes 31 to complete the batch lowering of the surface catheter 10, which is convenient for batch operation. The catheter base plate 30 includes an anti-sinking plate.

[0054] During the factory processing stage, the short section 101 of the surface conduit 10 and the thruster housing 46 are welded and installed, and the fuel and oxidant are loaded into the thruster 40. The lifting ship drives to the designated location, lowers the conduit base plate 30, and prepares for the installation of the surface conduit 10. The assembled surface conduit 10 is slowly lowered by the lifting cable 21 and connected to the conduit base plate 30. The surface conduit 10 relies on its own weight to enter the mud to a certain depth. During the lowering process, real-time observation can be performed by ROV. When the surface conduit 10 cannot be lowered by its own weight, the thruster 40 is started. The thruster 40 provides the power for the surface conduit 10 to continue to be lowered, and the control room on the water surface monitors and controls the entire lowering installation process in real time. After the surface conduit 10 is in place, the ROV removes the installation tools on the surface conduit 10 and recycles the installation tools. The ROV can observe the propulsion process throughout the whole process; the side wall of the surface conduit 10 can be set with a scale scale to facilitate the observation of the lowering depth by the ROV.

[0055] Embodiment 2

[0056] The present invention provides a method for installing a deep-water surface conduit, using the above-mentioned deep-water surface conduit installation device, such as Figure 5 As shown, the installation method includes: step S10, fixing the conduit base plate 30 to the seabed; step S20, lowering the surface conduit 10 to the seabed; step S30, starting the propeller 40, the propeller 40 generates thrust to drive the surface conduit 10 downward into the seabed soil 70.

[0057] The installation method has the following advantages: (1) it is easy to operate, shortens working time, and reduces operation costs; and (2) it is conducive to ensuring the quality of the installation of the surface conduit 10 and reducing the risk of deep-water operations.

[0058] In step S10, the conduit base plate 30 is directly connected to the ship's crane, stern A-frame or winch through a steel wire rope and slowly lowered to the seabed. The underwater conduit base plate 30 can be installed at a specified location through ROV assistance. In step S20, the surface conduit 10 is lowered to a certain depth by its own weight.

[0059] Step S30, start the thruster 40 underwater, and the thrust generated by the thruster 40 enables the surface conduit 10 to overcome the resistance of the soil 70 and continue to descend to the designed depth of the seabed mud line. During the descent process, the umbilical cable can be used to control the descent depth and the inclination angle, and the ROV can observe the whole process. When the control room receives a signal that the surface conduit 10 is tilted, the energy of the thruster 40 at the corresponding position is adjusted according to the inclination direction to make it descend vertically. The installation method also includes step S40, after the surface conduit 10 is installed in place, the ROV is used to release the suspension cable 21 and recover the relevant tools and equipment.

[0060] The fuel in the thruster 40 is filled according to the pre-calculated insertion depth to ensure that the energy required for the surface conduit 10 to reach the predetermined position is provided. After calculating the required insertion depth of the surface conduit 10 through soil mechanics calculation, the fuel and oxidant required for the insertion are loaded into the chamber; at the same time, a redundant chamber 42 is provided. When the soil conditions are complicated, or due to calculation errors or inaccurate predictions, after the predicted consumption of fuel is exhausted, an instruction is issued, and the redundant chamber 42 is put into use to continue to provide power for the thrust of the surface conduit 10, ensuring that the surface conduit 10 is delivered to the designated position.

[0061] The above are only several embodiments of the present invention. Those skilled in the art may make various changes or modifications to the embodiments of the present invention based on the contents disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims

1. A deepwater surface conduit installation device, characterized in that: include: Surface catheter, thruster, lowering mechanism and catheter base; A propeller is installed on the surface conduit and is used to apply a downward thrust to the surface conduit; The lowering mechanism is used to lower the surface conduit from the sea surface to the seabed; the conduit base plate can be fixed on the seabed, and the conduit base plate is used to straighten the surface conduit; The thruster comprises a combustion power mechanism and a filler chamber, wherein the combustion power mechanism comprises a nozzle, an engine, a combustion chamber and an oxidant chamber, and the filler chamber is used to provide fuel for the combustion power mechanism. By opening a valve between the filler chamber and the oxidant chamber, the fuel and the oxidant are burned in the combustion chamber, thereby driving the engine to provide power for lowering the surface conduit; The thruster further comprises a redundant compartment, the redundant compartment being connected to the combustion power mechanism, the redundant compartment being used to provide fuel to the combustion power mechanism after the fuel in the filler chamber is exhausted; The lowering mechanism comprises a suspension cable and a release buckle connected to the suspension cable. The upper end of the suspension cable is connected to an operating vessel or a drilling platform on the water surface, and the lower end of the suspension cable is connected to the surface conduit.

2. The deepwater surface conduit installation device according to claim 1, characterized in that: The installation device comprises at least three propellers, which are installed on the outer side of the upper end of the surface catheter, and at least three propellers are distributed circumferentially around the axis of the surface catheter.

3. The deepwater surface conduit installation device according to claim 1, characterized in that: The redundant bin is connected to the combustion power mechanism through the packing chamber, and a valve is provided between the redundant bin and the packing chamber.

4. The deepwater surface conduit installation device according to claim 1, characterized in that: The lower end of the surface conduit is configured to be closed.

5. The deepwater surface conduit installation device according to claim 4, characterized in that: The lower end of the surface conduit is provided with a cone portion.

6. The deepwater surface conduit installation device according to claim 1, characterized in that: The surface conduit is provided with a plurality of circumferentially distributed inclination sensors, and / or the upper end surface of the surface conduit is provided with a level meter.

7. The deepwater surface conduit installation device according to claim 1, characterized in that: The catheter base plate is provided with at least one central hole, and the surface catheter can be passed through the central hole.

8. A method for installing a deepwater surface conduit, characterized in that: The installation device of the deepwater surface conduit according to any one of claims 1 to 7 is used, and the installation method comprises: Step S10, fixing the catheter base plate to the seabed; Step S20, lowering the surface conduit to the seabed; Step S30, starting the propeller, the propeller generates thrust to drive the surface pipe downward into the seabed soil.

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