CN102071905A

CN102071905A - Anti-rotation self-locking rubber plug used for well cementation

Info

Publication number: CN102071905A
Application number: CN2011100404675A
Authority: CN
Inventors: 先勇; 张毅超; 杨万忠; 周正; 邹祥富
Original assignee: UNDERGROUND OPERATION COMPANY CNPC SICHUAN PETROLEUM GEOPHYSICAL PROSPECTING Co
Current assignee: UNDERGROUND OPERATION COMPANY CNPC SICHUAN PETROLEUM GEOPHYSICAL PROSPECTING Co; Changqing Downhole Operation Co of CNPC Chuanqing Drilling Engineering Co Ltd
Priority date: 2011-02-18
Filing date: 2011-02-18
Publication date: 2011-05-25

Abstract

The invention discloses an anti-rotation self-locking rubber plug used for well cementation, and belongs to the technical field of manufacturing of downhole tools for oil-gas field well cementing operations. The anti-rotation self-locking rubber plug used for the well cementation comprises an upper rubber plug, a lower rubber plug and a float collar, wherein plastic plates are arranged on both the upper rubber plug and the lower rubber plug; a self-locking core is arranged at the lower end of the lower rubber plug; upper self-locking cores are respectively arranged at the upper end and the lower end of the lower rubber plug; and a float collar self-locking core is arranged in the float collar. An automatic engagement self-locking mode is adopted; the anti-rotation self-locking rubber plug used for the well cementation is designed; the problem that the crushing efficiency of a drill on a rubber plug is influenced because a rubber plug is rotated along with the drill when implementing a drill isolated rubber plug is solved; and the anti-rotation self-locking rubber plug used for the well cementation has the characteristics of interlocking the upper rubber plug and the lower rubber plug.

Description

Well cementation anti-rotation self-locking plug

Technical field

A kind of well cementation is used for the oil gas well cementing operation operation of natural petroleum gas field with anti-rotation self-locking plug, belongs to the manufacturing technology field of the downhole tool of oil gas field well cementing operation.

Background technology

After the spudder finishes, can produce smoothly in order to make from now on, need carry out well cementing operation, but before implementing well cementing operation, owing to do not return out the drilling mud on ground in the well in addition, therefore, implement the conventional cementing operation, carry out before the cementing, just need to use plug that the cement paste of also staying the mud of down-hole in the sleeve pipe and be about to inject is separated, avoid causing the mixed slurry of drilling mud and cementing slurry, reach and prevent that cementing slurry from being taken place by the problem of drilling well mud contamination; Under the promotion of the displacement fluid of the isolation plug of putting into well before the cementing slurry, come downwards to the float collar bruising from well head, and then implement the work that cementing is starched, finally reach the effect that forms good cement sealing quality at the casing shoe place; Behind the technical application casing cementing, will continue to creep into, when creeping into, at first need to bore the front and implement isolation plug that well cementation is lowered to and supporting float collar, therefore, the isolation plug that is lowered to during well cementation and the easy brill of supporting float collar will become the saving drilling time, reduce the important tool of drilling cost;

Prior art is: all be plane contact basically between the isolation plug of use and the float collar, therefore, when drill bit implements to bore the isolation plug, plug is easy to rotate with drill bit, plug rotates with drill bit, will influence the crushing efficiency of drill bit to plug, prolonged the time that drill bit drills plug and supporting float collar, therefore and increased drilling period, improved drilling cost, and, casing wall has also been caused more serious wearing and tearing because drill bit rotates in the permanent position for a long time, buried hidden danger for later oil well production.

Summary of the invention

The objective of the invention is defective, adopt the mode of isolation plug and supporting float collar automatic engagement self-locking when replacing the slurry bruising, designed a kind of energy anti-rotation and the well cementation that realizes reverse pressure-bearing anti-rotation self-locking plug at prior art.

The present invention is achieved in that and the present invention includes top cement plug, bottom plug and float collar, it is characterized in that: on top cement plug and bottom plug, all be provided with lacquer disk(-sc) 1 and 4, all be provided with from

lock core

2,3 and 5 at the lower end of top cement plug, the upper and lower side of bottom plug, in float collar, be provided with float collar from lock core 6;

Top cement plug lower end and bottom plug lower end be provided with respectively four have positive briar tooth from

lock core

2 and 5, the float collar that is provided with in lock core 3 and float collar of bottom plug upper end has four anti-briar tooths from lock core 6.

The following positive briar tooth from lock core 5 that is provided with from lock core 2 and bottom plug lower end of described top cement plug lower end is according to 80～100 ° of PHASE DISTRIBUTION.

Described bottom plug upper end is provided with goes up from lock core 3 and float collar from the anti-briar tooth of lock core according to 80～100 ° of PHASE DISTRIBUTION.

During use, the top cement plug lower end is from the positive briar tooth 8 and going up from the mutual hook locking of the anti-briar tooth of lock core 3 that the bottom plug upper end is provided with of lock core 2, the following positive briar tooth 9 from lock core 5 that the bottom plug lower end is provided with locks from the mutual hook of four anti-briar tooths of lock core 6 with float collar, and rely on the rubber deformation of going up the bottom plug contact surface to keep retaining power, go up simultaneously the ring surface that bottom plug contacts with sleeve pipe and remain crimp, make to go up to lock mutually between the bottom plug to prevent to rotate, can rely on the crimp generation sealing function of ring surface to bear buffer brake again.

Advantage of the present invention and beneficial effect are: the top cement plug lower end of setting from lock core can with the locking mutually of bottom plug upper end from lock core, and the bottom plug lower end following from lock core also can with float collar realize locking from lock core, therefore, can when boring plug, prevent rotation with drill bit, has the efficient that increases substantially the broken cement plug of drill bit, and the saving drilling time, the characteristics of reduction drilling cost; In addition, because the lasting crimp of the ring-shaped rubber contact surface that brings when lock core locks mutually can make the sealing surface of plug and float collar bear buffer brake, the annular space cement paste that brings in the time of can eliminating the float collar seal failure pours in down a chimney back the hidden danger in the sleeve pipe.

Description of drawings

Fig. 1 is a broken section structural representation of the present invention.

The specific embodiment:

The present invention is provided by following most preferred embodiment:

Embodiment 1:

Structure of the present invention comprises top cement plug, bottom plug and three parts of float collar, on top cement plug and bottom plug, all be provided with lacquer disk(-sc) 1 and 4, be provided with from lock core 2 in the lower end of top cement plug, in order to be connected with the bottom plug self-locking, what the top cement plug lower end was provided with is four positive briar tooths 8 according to 90 ° of PHASE DISTRIBUTION from lock core 2; Be respectively arranged with from lock core 3 with down from lock core 5 at the upper and lower side of bottom plug, bottom plug to go up from lock core 3 are four anti-briar tooths according to 90 ° of PHASE DISTRIBUTION, the following of bottom plug is four positive briar tooths 9 according to 90 ° of PHASE DISTRIBUTION from lock core 5; Be provided with float collar from lock core 6 in float collar 7, float collar is anti-briar tooths according to 90 ° of PHASE DISTRIBUTION from lock core 6;

Embodiment 2:

Connection of the present invention is: the top cement plug lower end is from the positive briar tooth 8 and going up from the mutual hook locking of the anti-briar tooth of lock core 3 that the bottom plug upper end is provided with of lock core 2, the following positive briar tooth 9 from lock core 5 that the bottom plug lower end is provided with locks from the mutual hook of four anti-briar tooths of lock core 6 with float collar, the lacquer disk(-sc) 1 and 4 that is provided with on top cement plug and the bottom plug is to be made by rubber, when contacting with sleeve pipe, the ring surface that last bottom plug contacts with sleeve pipe remains crimp, make to go up to lock mutually between the bottom plug to prevent to rotate, can rely on the crimp generation sealing function of ring surface to bear buffer brake again.

Embodiment 3:

Concrete application examples of the present invention: a bite well at the Sichuan oil gas field is tested, well depth 1790m, be lowered to external diameter 177.8mm, the sleeve pipe 1788m of wall thickness 9.19mm, adopt the well cementation of the present invention and supporting float collar, infusion discharge capacity and pressure are steady in the work progress, no reflow phenomenon in the pipe after bruising puts in place, and plug and float collar effectively seal; Three spudding wells adopt the 152.4mm rock bit to bore 19 minutes times spent of plug, bore 240 minutes of plug average time than hole condition of the same type and save 130 minutes;

In implementation process, the positive briar tooth 8 from lock core 2 of the top cement plug lower end that is provided with can lock mutually with the anti-briar tooth from lock core 3 of bottom plug upper end, and the following positive briar tooth 9 from lock core 5 of bottom plug lower end also can be realized locking with the anti-briar tooth from lock core 6 of float collar, therefore, can when boring plug, prevent rotation with drill bit.

Claims

1. a well cementation is with anti-rotation self-locking plug, comprise top cement plug, bottom plug and float collar, it is characterized in that: on top cement plug and bottom plug, all be provided with lacquer disk(-sc), all be provided with from lock core, in float collar, be provided with float collar from lock core at the lower end of top cement plug, the upper and lower side of bottom plug; Top cement plug lower end and bottom plug lower end be provided with respectively four have positive briar tooth from lock core, the float collar that is provided with in lock core and float collar of bottom plug upper end has four anti-briar tooths from lock core.

2. well cementation according to claim 1 is characterized in that with anti-rotation self-locking plug: the following positive briar tooth from lock core that is provided with from lock core and bottom plug lower end of described top cement plug lower end is according to 80～100 ° of PHASE DISTRIBUTION.

3. well cementation according to claim 1 is characterized in that with anti-rotation self-locking plug: described bottom plug upper end is provided with goes up from lock core and float collar from the anti-briar tooth of lock core according to 80～100 ° of PHASE DISTRIBUTION.