A test method for a large hook of a drilling system

Abstract

This invention proposes a method for testing a drilling system hook, comprising the following steps: installing a lifting eye plate on the inner wall of a moonpool; confirming that test conditions are met; connecting the hook and the lifting eye plate; operating the drilling system to subject the hook to different loads; testing relevant indicators of the drilling system and hook under different loads; and finally, operating the drilling system to release the hook load and terminate the test. This method is simple, has a straightforward tooling structure, and is highly operable. It addresses the issue of limited space within the drilling system derrick and the high hook load, and can be applied to existing drilling vessels.

Description

Technical Field

[0001] The invention belongs to the technical field of offshore drilling equipment testing, and in particular relates to a testing method for a large hook of a drilling system. Background Art

[0002] Common drilling systems are generally assembled on offshore platforms, and crude oil is drilled and produced through platform operations. Since drilling platforms are only suitable for shallow water areas, semi-submersible platforms or drillships can only be used for deep sea exploration. Now, the world's maritime powers are developing drilling ships, integrating complex systems such as drilling systems and exploration systems on ships, and making better use of each integrated system through the unique performance of the ships.

[0003] Existing offshore drilling systems utilize a drilling platform with the drilling rig system mounted on a cantilever beam that slides outboard at the stern. The load on the drilling system's hook can be verified by hanging weights or water bags. However, the derrick of a drillship is fixed amidships, and a moonpool designed to connect to the sea is located in the midship area. Limited by the space available for the moonpool and the derrick, there is no space to suspend the load on the drilling system's hook, making it impossible to complete a load test on the hook. Furthermore, after the derrick is installed and commissioned, it is impossible to determine whether the hook load meets design requirements. Therefore, a test method specifically for the hook of a drillship's drilling system is needed. Summary of the Invention

[0004] In order to solve the problems existing in the above-mentioned prior art, the present application proposes a test method for a large hook of a drilling system, comprising the following steps:

[0005] Install eye plates on the inner wall of the moon pool;

[0006] Confirm that the test conditions are met;

[0007] Connect the big hook and the lifting eye plate;

[0008] Operate the drilling system to place the hook under different loads;

[0009] Test the relevant indicators of the drilling system and hook under different loads;

[0010] The load on the hook is released by operating the drilling system and the test is ended.

[0011] Furthermore, the eye plate for hanging points is provided on the inner wall of the moon pool, including:

[0012] Perform finite element calculation based on the load to obtain the parameters of the lifting point eye plate;

[0013] Weld the lifting point eye plate to the inner wall of the moon pool.

[0014] Furthermore, the parameters of the eyelet plate include: size, thickness and material of the eyelet plate.

[0015] Furthermore, confirmation of the test conditions includes:

[0016] First, check the drilling vessel to confirm that the hook and related equipment are working properly;

[0017] The loading water of the drilling vessel is then adjusted according to the pre-designed load test conditions.

[0018] Furthermore, the connection between the big hook and the lifting point eye plate includes:

[0019] Connect a continuous wire rope to each end of the alloy steel shackle;

[0020] Hang one of the endless wire ropes on the big hook;

[0021] providing a connector on another endless wire rope;

[0022] Connect the connector to the lifting eye plate.

[0023] Furthermore, the connecting piece is a pulley connected to the endless wire rope through a shackle, and connecting the connecting piece to the lifting point eye plate includes:

[0024] Hang a wire rope on the pulley.

[0025] Then the two ends of the wire rope are connected to the lifting point eye plate through shackles.

[0026] Furthermore, operating the drilling system to subject the hook to different loads includes:

[0027] Set up several load observation points;

[0028] Operate the drilling system so that the load reading on the dynamometer gradually increases;

[0029] When the reading on the dynamometer reaches the load observation point, the drilling system remains stationary at that position;

[0030] Observe the stress conditions of the drilling system's load-bearing structure under the load indicated by the load observation point.

[0031] Furthermore, observing the stress of the bearing structure of the drilling system under the load indicated by the load observation point also includes:

[0032] When the load-bearing structure of the drilling system reaches the load observation point with the maximum load;

[0033] Stay still for a while;

[0034] Check the stress conditions of each component of the load-bearing structure.

[0035] Furthermore, the stress conditions of the load-bearing structure include:

[0036] Observe the components of the load-bearing structure for cracks;

[0037] Check whether the wire rope connecting the load-bearing structure is broken.

[0038] Further, the operation of the drilling system to release the load on the hook and terminate the test includes:

[0039] The load-bearing structure has no defects in its stress condition;

[0040] Slowly lower the enlarged hook until the wire rope is completely relaxed, but do not remove it;

[0041] Surveyors read the deformation values ​​at various locations on the drilling system;

[0042] After checking, remove the tooling;

[0043] The experiment is over.

[0044] Compared with the prior art, the test method for the drilling system hook proposed in the present invention has the following advantages:

[0045] The test method of the present invention is simple, the tooling structure is simple, and the operability is strong; it solves the problems of narrow space in the derrick of the drilling system and heavy load on the hook, and can be extended to existing models of drilling ships. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a schematic diagram of the position of the eye plate of the present invention in the moon pool (top view).

[0047] Figure 2 Schematic diagram of the working state of the present invention,

[0048] Figure 3 It is a schematic diagram of the connection structure between the large hook and the lifting point eye plate of the present invention. DETAILED DESCRIPTION

[0049] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0050] The test method of the drilling system hook proposed in this application specifically includes the following steps:

[0051] Step 1: Make the eyelet plate

[0052] The specific form of the eye plate of the lifting point can refer to GB / T7029-1986. However, due to the heavy load of the large hook of the drilling system, the specific size of the eye plate needs to be calculated by finite element according to the load. The eye plate's external dimensions, plate thickness, material, etc. are determined by calculation.

[0053] Step 2: Welding the eye plate

[0054] Reference Figure 1 A lifting eye plate is installed on each of the four vertical walls of the moonpool, symmetrically arranged about the central axis of the moonpool. Due to the heavy load of the drilling system's large hook, the lifting eye plates are connected to the hull moonpool structure by welding. This welding method integrates the eye plate structure with the moonpool structure, facilitates the design of structural reinforcement for the lifting eye plates, and ensures that the structure at the welding point of the lifting eye plates can withstand the corresponding load.

[0055] Welding parameters such as Figure 2 As shown: double-sided butt welding is used; the weld is a K-shaped weld; the angle of the single-side groove is 45°; the groove gap is 0-2mm; there is no blunt edge between the two sides of the groove (that is, the depth of the single-side groove is 2 times the thickness of the eye plate). 1 ).

[0056] Step 3: Confirm that the test conditions are met

[0057] The ballast water of the ship is adjusted according to the pre-designed load test conditions, the draft of the drilling ship reaches the designed load test conditions, and the drilling ship is ensured to be in a balanced state in the front, back, left and right directions.

[0058] Step 4: Connect the big hook to the eye plate

[0059] Reference Figure 2 Depending on the specific work requirements, two of the lifting eyelets facing each other are selected as the connection points to the main hook (the left and right lifting eyelets are selected in the figure). The main hook of the drilling system is similar to the crane hook. The main hook and the lifting eyelet are connected with hardware (endless wire rope, alloy steel shackle, endless wire rope, pulley, shackle, wire rope, shackle). All connections are detachable, and hot work is not required.

[0060] The specific connection method of hardware is as follows Figure 3 As shown:

[0061] Connect a continuous wire rope to each end of the alloy steel shackle;

[0062] Hang one of the endless wire ropes on the big hook;

[0063] Two pulleys are set on another endless wire rope through two shackles;

[0064] Hang a wire rope on each pulley.

[0065] Both ends of the wire rope are connected to the lifting point eye plate through shackles.

[0066] By combining the pulley with the endless wire rope, a double movable pulley structure is realized, so that the endless wire rope only bears half of the load of the hook, and the wire rope connected to the eye plate of the lifting point only bears one-quarter of the load of the hook, ensuring the stability of the connection between the hook and the eye plate.

[0067] Step 5: Conduct the big hook test

[0068] By slowly operating the drilling system, the load on the dynamometer (the load is displayed on the tension display in the driller's room in the drilling system) is slowly increased, and load observation points are set, such as 20%, 50%, 80% and 100%;

[0069] When the load reaches the corresponding observation point, stop and check the stress conditions of each part, such as whether there are cracks in the structure, whether the wire rope is broken, etc., and continue the test after checking that there are no defects;

[0070] When the load reaches 100%, brake the main winch and keep it stationary for 10 minutes to check the stress conditions of each part.

[0071] After confirming that there are no defects under full load, slowly lower the enlarged hook until the wire rope is completely relaxed, but not removed. The measurement personnel read the deformation value at each position.

[0072] After checking that there are no problems, the tooling is removed and the test is completed.

[0073] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent changes and modifications made according to the patent scope of the present invention and the contents of the specification are within the scope covered by the patent of the present invention.

Claims

1. A method for testing a large hook of a drilling system, characterized in that: The following steps are involved: Install eye plates on the inner wall of the moon pool; Confirm that the test conditions are met; Connect the big hook and the lifting eye plate; Operate the drilling system to place the hook under different loads; Test the relevant indicators of the drilling system and hook under different loads; Remove the load from the hook and end the test by operating the drilling system; Finite element calculation is performed based on the load to obtain the parameters of the eyelet plate, including: the size, thickness and material of the eyelet plate; Weld the lifting point eye plate to the inner wall of the moon pool; Connecting hook and lifting eye plate include: Connect a continuous wire rope to each end of the alloy steel shackle; Hang one of the endless wire ropes on the big hook; providing a connector on another endless wire rope; Connect the connector to the lifting eye plate; The connecting piece is a pulley connected to the endless wire rope through a shackle, and connecting the connecting piece to the lifting point eye plate includes: Hang a wire rope on the pulley. Then, the two ends of the steel wire rope are connected to the lifting point eye plate through shackles; The operation of the drilling system to subject the hook to different loads includes: Set up several load observation points; Operate the drilling system so that the load reading on the dynamometer gradually increases; When the reading on the dynamometer reaches the load observation point, the drilling system remains stationary at that position; Observe the stress conditions of the drilling system's load-bearing structure under the load indicated by the load observation point; First, check the drilling vessel to confirm that the hook and related equipment are working properly; The loading water of the drilling vessel is then adjusted according to the pre-designed load test conditions.

2. A method for testing a large hook of a drilling system according to claim 1, characterized in that: Observation of the stress conditions of the drilling system's load-bearing structure under the load indicated by the load observation point also includes: When the load-bearing structure of the drilling system reaches the load observation point with the maximum load; Stay still for a while; Check the stress conditions of each component of the load-bearing structure.

3. A method for testing a large hook of a drilling system according to claim 2, characterized in that: Observation of the stress conditions of the load-bearing structure includes: Observe the components of the load-bearing structure for cracks; Check whether the wire rope connecting the load-bearing structure is broken.

4. A method for testing a large hook of a drilling system according to claim 1, characterized in that: The test is completed by operating the drilling system to release the hook load, including: The load-bearing structure has no defects in its stress condition; Slowly lower the enlarged hook until the wire rope is completely relaxed, but do not remove it; Surveyors read the deformation values ​​at various locations on the drilling system; After checking, remove the tooling; The experiment is over.

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