CN111021966A

CN111021966A - A settlement compensation method and settlement compensator used in offshore drilling

Info

Publication number: CN111021966A
Application number: CN201911259476.6A
Authority: CN
Inventors: 黄保黔; 王文; 郑波强; 张腾飞; 万文财
Original assignee: Guizhou Gaofeng Petroleum Machinery Co Ltd
Current assignee: Guizhou Gaofeng Petroleum Machinery Co Ltd
Priority date: 2019-12-10
Filing date: 2019-12-10
Publication date: 2020-04-17

Abstract

本发明公开了一种用于海洋钻井中的沉降补偿方法以及沉降补偿器，该沉降补偿器包括外部套筒以及螺纹连接在外部套筒上下两端的上接头和六方外套，在外部套筒内设置有贯穿六方外套的心轴，所述心轴的下端从六方外套内伸出，在心轴的上端螺纹连接有密封限位座，在心轴上且位于密封限位座与六方外套之间套有缓冲弹簧，所述心轴的外形为六方结构，心轴与六方外套上的内六方孔滑动配合。本发明通过六方结构来传递上部钻具和下部钻具之间的扭矩，并能在轴线方向自由移动，消除钻压波动带来的影响；同时，在钻压波动剧烈的情况下，由于在两个活动组件之间安装缓冲弹簧，当两个活动组件即将碰撞时发挥缓冲作用，避免出现刚性碰撞而对钻柱产生伤害。The invention discloses a settlement compensation method used in offshore drilling and a settlement compensator. The settlement compensator comprises an outer sleeve, an upper joint and a hexagonal outer sleeve threadedly connected to the upper and lower ends of the outer sleeve. There is a mandrel running through the hexagonal jacket, the lower end of the mandrel protrudes from the hexagonal jacket, the upper end of the mandrel is threadedly connected with a sealing limit seat, and a buffer is sleeved on the mandrel and located between the sealing limit seat and the hexagonal jacket The shape of the mandrel is a hexagonal structure, and the mandrel is slidably matched with the inner hexagonal hole on the hexagonal outer casing. The present invention transmits the torque between the upper drilling tool and the lower drilling tool through the hexagonal structure, and can move freely in the axial direction to eliminate the influence caused by the WOB fluctuation; A buffer spring is installed between the two movable components to play a buffering role when the two movable components are about to collide, so as to avoid rigid collision and damage to the drill string.

Description

Settlement compensation method and settlement compensator for offshore drilling

Technical Field

The invention relates to a settlement compensation method and a settlement compensator for offshore drilling, belonging to the technical field of oil exploitation.

Background

With the development of the use of oil and gas and the exploration of reserves, land resources have gradually reached a saturated state. In sharp contrast, the proven reserves of marine oil and gas have increased year by year. The development of marine oil and natural gas has become the main development direction of all countries at present. Especially, the emergence of combustible ice resources in recent years provides more choices for future energy use. The continuous exploration and expansion of ocean energy sources enable the development of ocean resources to have more important strategic significance.

In the ocean drilling, a drilling platform is built on the sea surface, and the drilling operation is carried out below the sea surface through the drilling platform. Because the sea surface is influenced by tide and sea wave and is always in a dynamic state of moving up and down, the drilling pressure fluctuation is obvious in the drilling operation, the drilling efficiency is greatly reduced, and the development speed of ocean resources is restricted. When sea surface stormy waves are large, the drilling pressure fluctuates severely, the drill bit loses pressure and cannot work when the conditions are serious, and the drill bit is damaged under particularly serious conditions, so that the drilling work is suspended, and the drilling period is delayed.

Disclosure of Invention

The invention aims to provide a settlement compensation method and a settlement compensator for ocean drilling, which have the advantages of ingenious structure, convenient use, safety and reliability, so as to solve the problem of severe drilling pressure fluctuation caused by the influence of tides and sea waves on the sea surface in the drilling operation process, ensure the normal drilling and improve the drilling efficiency.

The technical scheme of the invention is as follows: a settlement compensation method used in ocean well drilling, first connect the settlement compensator which can normally transmit torque and can move freely up and down to the tension and compression balance position between the upper drilling tool and the lower drilling tool, when in operation, the settlement compensator can play the function of normal torque transmission to drive the drill bit to carry out normal well drilling operation; when the sea surface is influenced by tides and sea waves, the operation platform moves up and down, and at the moment, the settlement compensator eliminates the influence of the sea surface settlement on a drilling tool at the lower part by playing the function of free movement up and down, so that the normal operation of drilling is ensured.

In the method, when the sea surface is greatly influenced by tides and sea waves, the operation platform moves up and down violently, the settlement compensator cannot completely eliminate the influence of the sea surface settlement on normal drilling by exerting the function of moving up and down freely, the buffer spring is arranged in the settlement compensator, and is compressed to enter a working state, so that the influence state of the up-and-down displacement on the drill bit is relieved, rigid collision between the upper drilling tool and the lower drilling tool is avoided, and the whole drill string system is protected to the maximum extent.

Meanwhile, the invention also provides a settlement compensator for offshore drilling based on the settlement compensation method, which comprises an external sleeve, an upper joint and a hexagonal jacket, wherein the upper joint and the hexagonal jacket are in threaded connection with the upper end and the lower end of the external sleeve, a mandrel penetrating through the hexagonal jacket is arranged in the external sleeve, the lower end of the mandrel extends out of the hexagonal jacket, the upper end of the mandrel is in threaded connection with a sealing limit seat, a buffer spring is sleeved on the mandrel and positioned between the sealing limit seat and the hexagonal jacket, the mandrel is in a hexagonal structure, the hexagonal structure on the mandrel is in sliding fit with an inner hexagonal hole in the hexagonal jacket, an upper connecting thread is arranged on the upper joint, and a lower connecting thread is arranged at the lower end of the mandrel.

Further, the outer wall of the sealed limit seat is in sliding fit with the inner wall of the external sleeve, an annular groove is formed in the outer wall of the sealed limit seat, and a sealing ring is installed in the annular groove.

Further, a sealing ring is arranged at the joint of the sealing limiting seat and the mandrel.

Furthermore, an external pressure balance hole is formed in the side wall of the external sleeve.

Due to the adoption of the technical scheme, the invention has the advantages that: the invention can normally transmit torque and can freely move up and down through the settlement compensator, thereby eliminating the influence of sea surface and bit pressure fluctuation on the whole drill string; meanwhile, under the condition that the sea surface and the bit pressure fluctuate severely, the buffer spring is arranged between the two movable assemblies in the settlement compensator, so that the buffer effect is exerted when the two movable assemblies are about to collide, and the damage to a drill string caused by rigid collision is avoided through the buffer spring. Therefore, the invention can ensure normal drilling under the condition that the sea surface is influenced by tides and sea waves, and improve the drilling efficiency.

Drawings

Fig. 1 is a schematic structural view of the present invention.

FIG. 2 is a cross-sectional view A-A of FIG. 1;

FIG. 3 is a schematic diagram of the present invention in a suspended state;

fig. 4 is a schematic structural view of the present invention in a shock-absorbing state of the buffer spring.

The labels in the figures are: 1-upper joint, 2-external sleeve, 3-hexagonal jacket, 4-mandrel, 5-sealing ring, 6-sealing limiting seat, 7-buffer spring, 8-external pressure balance hole, 9-upper connecting thread and 10-lower connecting thread.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the accompanying drawings and examples.

The embodiment of the invention comprises the following steps: the settlement compensator for the offshore drilling comprises an outer sleeve 2, an upper joint 1 and a hexagonal outer sleeve 3, wherein the upper joint 1 and the hexagonal outer sleeve 3 are in threaded connection with the upper end and the lower end of the outer sleeve 2, a mandrel 4 penetrating through the hexagonal outer sleeve 3 is arranged in the outer sleeve 2, the lower end of the mandrel 4 extends out of the hexagonal outer sleeve 3, a sealing limiting seat 6 is in threaded connection with the upper end of the mandrel 4, a buffer spring 7 is sleeved on the mandrel 4 and positioned between the sealing limiting seat 6 and the hexagonal outer sleeve 3, the mandrel 4 is in a hexagonal structure, the hexagonal structure on the mandrel 4 is in sliding fit with an inner hexagonal hole in the hexagonal outer sleeve 3, an upper connecting thread 9 is arranged on the upper joint 1, and a lower connecting thread 10 is arranged at the lower end of the. The outer wall of the sealing limiting seat 6 is in sliding fit with the inner wall of the outer sleeve 2, an annular groove is formed in the outer wall of the sealing limiting seat 6, and a sealing ring 5 is installed in the annular groove; and a sealing ring 5 is arranged at the joint of the sealing limiting seat 6 and the mandrel 4, and the sealing ring 5 can block liquid flow between the inside and the outside to ensure normal circulation of drilling fluid. And the side wall of the outer sleeve 2 is provided with an outer pressure balance hole 8 for balancing the inner and outer pressure difference.

The working principle of the invention is as follows:

when in use, the settlement compensator of the invention is connected between an upper drilling tool and a lower drilling tool, namely the upper drilling tool and the lower drilling tool are respectively connected through an upper connecting thread 9 and a lower connecting thread 10. Referring to fig. 3, in the working process, as the upper drilling tool is pulled, the lower drilling tool is pressed, and the settlement compensator is in a suspension state, during normal operation, the settlement compensator transmits torque through the hexagonal structure on the mandrel 4 and the inner hexagonal hole on the hexagonal outer sleeve 3 to drive the drill bit to perform normal drilling operation; when the sea surface is influenced by tides and sea waves, the operation platform moves up and down, and at the moment, the hexagonal structure on the mandrel 4 moves up and down in the inner hexagonal hole in the hexagonal sleeve 3, so that the influence of sea surface settlement on the upper drilling tool and the lower drilling tool is eliminated, and the normal operation of drilling operation is ensured.

Referring to fig. 4, when the sea surface is greatly affected by tides and sea waves, the operation platform moves up and down violently, at the moment, the hexagonal structure on the mandrel 4 moves up and down violently in the inner hexagonal hole on the hexagonal outer sleeve 3, the influence of sea surface settlement on normal drilling cannot be completely eliminated, when the displacement amplitude of the mandrel 4 increases, the buffer spring 7 is compressed to enter a working state, the influence state of the up-and-down displacement on the drill bit is relieved, rigid collision between the upper drilling tool and the lower drilling tool is guaranteed not to occur, and the whole drill string system is protected to the maximum extent.

Claims

1. a settlement compensation method used in marine drilling is characterized in that: firstly, the settlement compensator that can normally transmit torque and can move up and down freely is connected to the tension-pressure balance between the upper drilling tool and the lower drilling tool position, during operation, the settlement compensator exerts the normal torque transmission function to drive the drill bit to carry out normal drilling operations; when the sea surface is affected by tides and waves, the working platform moves up and down, and the settlement compensator moves up and down freely at this time. The influence of sea surface subsidence on the lower drilling tools ensures the normal operation of drilling work.

2. The settlement compensation method used in marine drilling according to claim 1, is characterized in that: when the sea surface is greatly influenced by tides and waves, the working platform moves violently up and down, and the settlement compensator is free to play up and down at this moment. The movement function cannot completely eliminate the influence of sea surface subsidence on normal drilling. There is a buffer spring inside the subsidence compensator. The buffer spring is compressed and enters the working state, slowing down the influence of the up and down displacement on the drill bit, and ensuring the upper drilling tool and lower drilling. There will be no rigid collision between tools, and the entire drill string system will be protected to the greatest extent.

3. A settlement compensator for marine drilling based on the settlement compensation method for marine drilling according to claim 1 or 2, comprising an outer sleeve (2) and a threaded connection on the outer sleeve (2) The upper joint (1) and the hexagonal outer sleeve (3) at the upper and lower ends are characterized in that: a mandrel (4) passing through the hexagonal outer sleeve (3) is arranged in the outer sleeve (2), The lower end protrudes from the hexagonal outer casing (3), and the upper end of the mandrel (4) is threadedly connected with a sealing stop seat (6), which is located on the mandrel (4) and is located between the sealing stop seat (6) and the hexagonal outer casing (3) A buffer spring (7) is set between them, and the shape of the mandrel (4) is a hexagonal structure. 1) An upper connecting thread (9) is provided on it, and a lower connecting thread (10) is provided on the lower end of the mandrel (4).

4. The settlement compensator used in offshore drilling according to claim 3, characterized in that: the outer wall of the sealing limit seat (6) is slidingly matched with the inner wall of the outer sleeve (2), and the sealing limit seat (6) is in sliding fit with the inner wall of the outer sleeve (2). An annular groove is formed on the outer wall of the seat (6), and a sealing ring (5) is installed in the annular groove.

5 . The settlement compensator for offshore drilling according to claim 4 , wherein a sealing ring ( 5 ) is installed at the connection between the sealing limit seat ( 6 ) and the mandrel ( 4 ). 6 .

6 . The settlement compensator for offshore drilling according to claim 5 , wherein an external pressure balance hole ( 8 ) is opened on the side wall of the outer sleeve ( 2 ). 7 .