Depth reference device for offshore drilling standard penetration test

Abstract

The utility model discloses a depth reference device for an offshore drilling standard penetration test. The depth reference device comprises a scale and a gravity fixing block, the ruler is connected to the base plate, and an inelastic first inhaul cable is connected between the base plate and the gravity fixing block. The gravity fixing block comprises two C-shaped sleeves, one ends of the two C-shaped sleeves are hinged, and the other ends of the two C-shaped sleeves are detachably connected through a lock catch. The ruler is made of stainless steel and is welded to a base plate made of stainless steel, and a handheld handle is welded to the base plate. The bottom end of the base plate is connected with a cable buckle a, an upper opening of the gravity fixing block is connected with a cable buckle b, and the two ends of the first inhaul cable are connected to the cable buckle a and the cable buckle b respectively. Compared with the prior art, the influence of surges on the standard penetration test is avoided, and the obtained standard penetration test data is more accurate.

Description

Technical Field

[0001] The utility model relates to the technical field of marine geological survey, in particular to a depth reference device for offshore drilling standard penetration test. Background Art

[0002] The development and utilization of the ocean has gradually developed from the coastline to the near and far seas and even deeper. The main challenges for offshore geological surveys are drilling operations ships, operating platforms, construction technology, construction methods, deep water and large waves. At present, such problems have been basically solved or improved, but there are still major problems in the reference of penetration depth during standard penetration tests.

[0003] At present, in the standard penetration test of marine geological survey, the upper end of the casing is mainly used as the fixed reference point, and the zero point line is marked with the corresponding drill rod position. The scale of the corresponding length is marked upward along the zero point line on the drill rod. When the penetration hammer drives the drill rod downward into the soil layer, the scale on the drill rod is compared with the upper end of the casing to know the penetration depth of the drill rod when a certain number of hammer blows is given.

[0004] In order to prevent the casing from falling off with the rise and fall of the tide and to facilitate the upper and lower casing, the upper end of the casing is often fixed to the drilling platform with a splint. In this way, the casing moves up and down with the waves, while the standard penetration drill rod is directly placed in the soil layer at the corresponding depth below the seabed in the casing and does not move up and down with the changes in the waves. This causes inaccuracy in the reference point for the standard penetration test, and there is room for greater improvement in the selection of fixed reference objects. Utility Model Content

[0005] The utility model aims to provide a depth reference device for offshore drilling standard penetration test, which eliminates the influence of swell on standard penetration test and obtains more accurate standard penetration test data, so as to solve the problems raised in the above-mentioned background technology.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A depth reference device for offshore drilling standard penetration test comprises a ruler and a gravity fixing block; the ruler is connected to a base plate, a first elastic cable is connected between the base plate and the gravity fixing block; the gravity fixing block comprises two C-shaped sleeves, one end of the two C-shaped sleeves is hinged, and the other end is detachably connected through a lock.

[0008] A further improvement of the utility model is that the ruler is made of stainless steel, the ruler is welded to a base plate made of stainless steel, and a hand-held handle is welded to the base plate.

[0009] A further improvement of the utility model is that a cable buckle a is connected to the bottom end of the base plate, a cable buckle b is connected to the upper opening of the gravity fixing block, and two ends of the first cable are respectively connected to the cable buckle a and the cable buckle b.

[0010] A further improved solution of the utility model is that one end of the C-shaped sleeve is connected by a hinge.

[0011] A further improvement of the utility model is that the inner wall of the gravity fixing block is in a convex arc shape.

[0012] A further improvement of the utility model is that it also includes a second inelastic cable, the upper opening of the gravity fixing block is connected with a cable buckle c symmetrical to the cable buckle b, the bottom end of the second cable is connected to the cable buckle c, and the top end of the second cable is connected to the drilling platform.

[0013] A further improvement of the utility model is that both the first cable and the second cable are inelastic parachute cords.

[0014] Beneficial effects of the utility model:

[0015] The utility model discloses a depth reference device for offshore drilling standard penetration test, which obtains more accurate standard penetration test data and saves waiting time, and the device can be reused.

[0016] The depth reference device for offshore drilling standard penetration test of the utility model can also reduce the safety risks caused by the up and down movement of the casing when marking the length on the drill pipe, and can be used as a measuring rope for measuring water depth.

[0017] The utility model discloses a depth reference device for offshore drilling standard penetration test, which reduces the time of waiting for a fixed reference object to be relatively stable, and significantly shortens the drilling auxiliary operation time; it not only reduces the physical strength of construction personnel, but also improves work efficiency.

[0018] The utility model discloses a depth reference device for offshore drilling standard penetration test. The material used has anti-corrosion and anti-rust functions, so the device is easy to be repeatedly used for a long time.

[0019] The utility model discloses a depth reference device for offshore drilling standard penetration test, wherein the inner wall of the gravity fixing block is convex arc-shaped, thereby reducing the contact area between the gravity fixing block and the casing, and facilitating the gravity fixing block to smoothly sink to the seabed without being stuck by the joint of the casing.

[0020] The utility model discloses a depth reference device for offshore drilling standard penetration test, which is provided with a second cable, and can ensure that the gravity fixing block does not tilt when the gravity fixing block is lowered or raised, thereby preventing the gravity fixing block from being stuck. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0022] Figure 2 It is a schematic diagram of the scale structure of the utility model.

[0023] Figure 3This is a schematic diagram of the gravity fixing block structure of the utility model.

[0024] Figure 4 for Figure 3 Cross-sectional view at AA in the middle.

[0025] In the figure: 1-ruler, 2-gravity fixing block, 201-C-shaped sleeve, 202-lock, 203-cable b, 204-hinge, 205-cable c, 3-base plate, 301-hand handle, 302-cable a, 4-first cable, 5-second cable, 6-construction ship, 601-drilling platform, 602-drilling tower, 603-drilling equipment, 604-casing, 605-drill pipe. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0027] Example 1: Figures 1 to 4 As shown, a depth reference device for offshore drilling standard penetration test includes a ruler 1 with a length of 50 cm and a gravity fixed block 2; the ruler 1 is connected to a base plate 3, and a first inelastic cable 4 is connected between the base plate 3 and the gravity fixed block 2, and the first cable 4 is used to measure the standard penetration or extract the gravity fixed block 2; the gravity fixed block 2 is a casing 604 with a diameter of 246 mm and a height of 300 mm as a whole, which is cut into two C-shaped sleeves 201 along the central axis, one end of the two C-shaped sleeves 201 is hinged, and the other end is detachably connected through a lock buckle 202.

[0028] The ruler 1 is made of stainless steel, and is welded on a 600mm*50mm*10mm stainless steel substrate 3 , on which a handheld handle 301 is welded.

[0029] Among them, the bottom end of the base plate 3 is connected with a cable buckle a302, the upper opening of the gravity fixing block 2 is connected with a cable buckle b203, and the two ends of the first cable 4 are respectively connected to the cable buckle a302 and the cable buckle b203.

[0030] One end of the C-shaped sleeve 201 is connected via a hinge 204 .

[0031] Among them, the inner wall of the gravity fixing block 2 is convex arc-shaped, with the narrowest diameter of 186mm in the middle, and it is polished smooth to facilitate smooth sinking to the seabed without being stuck by the casing 604 joint. When the gravity does not meet the requirements, the weight block can be evenly welded on the outside of the gravity fixing block 2.

[0032] Embodiment 2: This embodiment is a further improvement of Embodiment 1. The main improvement is that when Embodiment 1 is in use, there is only the first cable 4 at the upper opening of the gravity fixing block 2. In the process of lowering or pulling up the gravity fixing block 2, the gravity fixing block 2 is prone to tilt and get stuck. In this embodiment, the above defects can be avoided. Specifically:

[0033] It also includes a second inelastic cable 5, the upper end of the gravity fixing block 2 is connected to a cable buckle c205 symmetrical to the cable buckle b203, the bottom end of the second cable 5 is connected to the cable buckle c205, and the top end of the second cable 5 is connected to the drilling platform 601 to extract the gravity fixing block 2 or use it as a safe reserve; the first cable 4 and the second cable 5 are both inelastic parachute ropes; in this embodiment, a second cable 5 is added to ensure that the gravity fixing block 2 does not tilt when the gravity fixing block 2 is lowered or pulled up, thereby avoiding the gravity fixing block 2 from being stuck.

[0034] Apart from this, this embodiment is exactly the same as Embodiment 1 and will not be described in detail here.

[0035] The specific working principle of the utility model is as follows:

[0036] The construction ship 6 is a common equipment for marine geological survey. A drilling platform 601 is provided on the construction ship 6, and a marine drilling tower 602 and drilling rig equipment 603 are installed.

[0037] After the casing 604 is lowered and fixed, the two C-shaped sleeves 201 of the gravity fixing block 2 are placed on the outside of the casing 604, and the lock buckle 202 is fixed. The operator holds the first cable 4 and the second cable 5 to sink the gravity fixing block 2 along the casing 604 to the seabed, so that the gravity fixing block 2 will not move with the tide. The gravity fixing block 2 is connected to the scale 1 through the first cable 4, so that it is completely separated from the drilling platform 601, the casing 604, etc., and will not change with changes in waves, etc. The first cable 4 changes with the water depth, the remaining amount on the drill rod 605 above the drilling platform 601, etc., to ensure that the upper end of the scale 1 is greater than the penetration depth of the penetration hammer.

[0038] During the standard penetration test, it is only necessary to mark the position corresponding to the drill rod 605 at the "0" point on the ruler 1. During the penetration test, it is only necessary to observe the marked point on the drill rod 605 and the corresponding scale on the ruler 1 to know the penetration depth.

[0039] The above implementation is only to illustrate the technical concept and features of the utility model, and its purpose is to enable people familiar with this technology to understand the content of the utility model and implement it accordingly, and it cannot be used to limit the protection scope of the utility model. Any equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. A depth reference device for offshore drilling standard penetration test, characterized in that: The invention comprises a scale (1) and a gravity fixing block (2); the scale (1) is connected to a base plate (3); a first non-elastic pull cable (4) is connected between the base plate (3) and the gravity fixing block (2); the gravity fixing block (2) comprises two C-shaped sleeves (201); one end of the two C-shaped sleeves (201) is hinged, and the other end is detachably connected via a lock buckle (202).

2. A depth reference device for offshore drilling standard penetration test according to claim 1, characterized in that: The scale (1) is made of stainless steel, the scale (1) is welded to a base plate (3) made of stainless steel, and a hand-held handle (301) is welded to the base plate (3).

3. A depth reference device for offshore drilling standard penetration test according to claim 2, characterized in that: The bottom end of the base plate (3) is connected to a cable buckle a (302), the upper end of the gravity fixing block (2) is connected to a cable buckle b (203), and the two ends of the first pull rope (4) are respectively connected to the cable buckle a (302) and the cable buckle b (203).

4. A depth reference device for offshore drilling standard penetration test according to claim 1, characterized in that: One end of the C-shaped sleeve (201) is connected via a hinge (204).

5. A depth reference device for offshore drilling standard penetration test according to claim 1, characterized in that: The inner wall of the gravity fixing block (2) is in a convex arc shape.

6. A depth reference device for offshore drilling standard penetration test according to any one of claims 1 to 5, characterized in that: It also includes a second inelastic cable (5), the upper end of the gravity fixing block (2) is connected to a cable buckle c (205) symmetrical to the cable buckle b (203), the bottom end of the second cable (5) is connected to the cable buckle c (205), and the top end of the second cable (5) is connected to the drilling platform (601).

7. A depth reference device for offshore drilling standard penetration test according to claim 6, characterized in that: The first cable (4) and the second cable (5) are both inelastic parachute cords.

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