CN103452509A - Wellhead descending tool - Google Patents

Abstract

The invention relates to an underwater wellhead lowering tool for offshore oil and gas exploitation, which includes a mandrel, an upper support block, a lower support block, a driving block, a locking ring and a protective cover, and the upper support block and the lower support block are sleeved on the mandrel through bolt connection , the mandrel and the drive block are connected by threads, the drive block has an axial through hole to pass through the bolt to guide, the open elastic lock ring is installed between the drive block and the lower support block, and the protective cover is located at the top and connected to the upper support by bolts on the block. The invention not only can effectively lower and recover the well head, but also has a simple structure and convenient loading and unloading procedures, can realize quick installation and recovery of the well head, and improves work efficiency.

Description

A wellhead lowering tool

technical field

The invention relates to an underwater wellhead lowering tool for marine oil and gas exploitation, which is used for lowering and installing the underwater wellhead.

Background technique

Since offshore oil and gas exploitation has become an important development direction of energy development, the lower part of the subsea wellhead system supports various casings on the seabed, and the upper part carries blowout preventers and Christmas trees, which is the basis for underwater oil production. Most of the investment in offshore oil and gas exploration is used for the installation of subsea equipment. Therefore, simple and convenient lowering tools and simple installation procedures to reduce installation costs are the goals that offshore oil and gas exploration has been pursuing. The existing tools for lowering the wellhead head for offshore oil and gas production have the following shortcomings: 1. The tool structure is complex, there are many parts, and the loading and unloading process is complicated and time-consuming; 2. The reliability is low, and the wellhead head cannot be locked or released as required; 3. The process of lowering the wellhead head There is bump and friction.

Contents of the invention

The technical problem to be solved by the present invention is to provide an underwater wellhead lowering tool, which can not only effectively lower and install the wellhead, but also has a simple structure and easy loading and unloading procedures, can realize the rapid installation and recovery of the wellhead, and improve work efficiency.

The technical solution adopted by the present invention in order to solve the above-mentioned problems is: a wellhead lowering tool, which is characterized in that it includes a mandrel, the middle part of the mandrel is threaded to connect with the drive block, and the upper support block and the lower support block In the axial space; the outer periphery of the drive block has an axial through hole, which passes through the bolt to play a guiding role, and the lower half of the drive block is in direct contact with the open elastic lock ring; the lower part of the open elastic lock ring sits on the lower support On the block, there are occlusal alveoli on the outside that are configured with the lower occlusal alveolar surface of the wellhead head; the upper support block and the lower support block are connected by bolts to play a positioning role.

According to the above solution, the inner annular mandrel is characterized in that the mandrel is a stepped shaft, and the intermediate step shaft is threaded to connect with the driving block.

According to the above scheme, the annular entity of the upper supporting block is provided with through holes, and a plurality of threaded holes are provided on the outer edge plate.

According to the above scheme, the lower support block is provided with an annular sealing groove, and the annular body is provided with a threaded through hole.

According to the above solution, the inner side of the upper end of the open elastic lock ring is a slope that wraps the lower slope of the driving block.

According to the above solution, the lower end of the protective cover is a trumpet-shaped opening, and the upper end plane is provided with annularly distributed through holes.

The beneficial effects of the present invention are as follows: 1. The lowering tool has an external protective cover to prevent the collision and friction of the wellhead head lowering process, and play a guiding role; 2. It adopts threaded connection, and the rotating mandrel makes the driving block move down safely and reliably; 3. 1. The locking with the wellhead head is achieved through the open elastic lock ring, which is simple and convenient; 4. The installation and release of the wellhead head are easy to operate, and can be quickly installed and released, saving installation time and improving efficiency.

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Description of drawings

Fig. 1 is a schematic diagram of the present invention.

Fig. 2 is a schematic diagram of an unlocked wellhead head of the present invention.

Fig. 3 is a schematic diagram of the locking wellhead head of the present invention.

Fig. 4 is a schematic diagram of the elastic locking ring of the present invention.

Detailed ways

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

Referring to FIG. 2 , the wellhead head lowering tool of the present invention includes a mandrel 1 , a long bolt 2 , a short bolt 3 , a protective cover 4 , an upper support block 5 , a drive block 6 , an open elastic locking ring 7 and a lower support block 8 .

The well head lowering tool mandrel 1 is a stepped shaft, and there are threads at the middle step shaft to be connected with the driving block. The two ends of the stepped shaft where the threads are located naturally form baffles to locate the positions of the upper support block 5 and the lower support block 8 . There are tapered threads in the holes at the upper and lower ends of the mandrel 1, the upper thread is used for connecting drill pipes or other casings, and the lower thread is used for connecting other flushing tools. The drive block 6 is screwed onto the spindle 1 . An axial through hole is arranged on the ring entity of the drive block 6 to cooperate with the axial through hole of the upper support block 5 and the threaded hole on the lower support block 8 , and is configured with the long bolt 2 . The upper supporting block 5 is seated on the boss of the mandrel 1 , the annular entity has a through hole for passing through the long bolt 2 , and a threaded hole is arranged on the outer edge for installing the protective cover 4 . The lower support block 5 has threaded holes on the annular entity, and is pressed on the mandrel 1 by the long bolt 2; the outer diameter of the lower support block 4 is provided with an annular sealing groove. The open elastic locking ring 7 is a circular ring with an opening, and the outside is a toothed locking groove configured with the locking groove on the wellhead head 10 . Only the lower end of the long bolt 2 is threaded, and is used to connect the lower support plate, and the middle piece rod part plays a guiding role for the driving block 6 .

The installation and release process of the present invention is as follows: connect a lowering tool to the drill pipe through the tapered thread on the top of the mandrel 1, lower it into the wellhead, and rotate the inner annular mandrel 1 to make it move relative to the driving block 6 , because of the guiding effect of the long bolt 2, the driving block 6 can only squeeze downward into the elastic locking ring 7, causing the elastic locking ring 7 to expand and lock in the locking groove in the wellhead head, so that the wellhead head is locked on the entire tool. Lower the wellhead head into the inside of the catheter head on the seabed. After reaching the installation position, reverse the drill pipe to reverse the mandrel 1 to cause the drive block 6 to go up, and the elastic lock ring 7 is retracted. The entire tool is separated from the wellhead head, and the entire installation process is completed. , to lift the tool back to the platform.

Claims (6)

1. a well head head is transferred instrument, includes axle (1), and axle 1 middle part has screw thread to be connected with drive block (6), in the axial space between upper support piece (5) and lower support piece (8); Described drive block (6) periphery has axially extending bore, through bolt (2), plays guide effect, and drive block (6) Lower Half directly contacts with opening elastic lock ring (7); Described opening elastic lock ring (7) bottom sits that to be placed on lower support piece (8) upper, and what there were interlock teeth groove and a well head head (10) in outside transfers tooth engaged groove face phase configuration; Described upper support piece (5) is connected and plays positioning action by bolt (2) with lower support piece (8); The whole instrument of transferring has protective cover (4) parcel be connected on the upper support piece, and protective cover (4) is for the protection of outer wellhead parietal tooth groove.

2. axle claimed in claim 1 (1), it is characterized in that: axle (1) is a multidiameter, at scala media axle place, has screw thread to be connected with drive block (6), and the upper and lower two ends of axle (1) endoporus has tapered thread, upper end is for jointed rod or other sleeve pipes, and lower end is for connecting washover tool.

3. upper support piece claimed in claim 1 (5), it is characterized in that: annular entity has through hole, has screwed hole on curtain plate.

4. lower support piece claimed in claim 1 (8), is characterized in that: open survey and have annular seal groove (9), on annular entity, have screwed hole.

5. opening elastic lock ring claimed in claim 1 (7), it is characterized in that: the inboard, upper end is that an inclined-plane coordinates with drive block (6) lower bevel.

6. protective cover claimed in claim 1 (4), it is characterized in that: lower end is horn-like opening, and upper transverse plane has the through hole of annular spread.

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