CN203614051U

CN203614051U - Big-pitch casing thread joint

Info

Publication number: CN203614051U
Application number: CN201320694218.2U
Authority: CN
Inventors: 张小燕
Original assignee: Wuxi Seamless Oil Pipe Co Ltd
Current assignee: Wuxi Seamless Oil Pipe Co Ltd
Priority date: 2013-11-06
Filing date: 2013-11-06
Publication date: 2014-05-28
Anticipated expiration: 2023-11-06

Abstract

With the development of the petroleum industry, in the case of limited onshore oilfield increment, the oil development gradually develops towards offshore oil and gas wells. The offshore oilfield operation is significantly influenced by wind power, for the existing big-pitch casing, common API threads are difficultly centered to cause thread alternating, the thread pitch is relatively small and the spinning time is long, so that the ocean exploration and development cost is high. Moreover, problems such as insufficient strength and bad sealing performance exist. The utility model provides a big-pitch casing thread joint, which uses coarse threads, namely, threads with 3 to 5 teeth per inch; simultaneously, a right-angle outer torque shoulder is arranged at the tail end of the inner side of the outer threads, and the right-angle outer torque shoulder in the fastening state is in interference fit with the corresponding end of the internal thread. The tooth top and tooth bottom of the threads are parallel to the central axis; an included angle between the bearing surface of the threads and the central axis is 90 DEG; an acute angle between the guiding surface of the threads and the vertical line of the central axis is 30 to 35 DEG.

Description

A kind of coarse pitch casing thread connection

Technical field

The utility model belongs to oil well pipe thread connection device field, is specially a kind of coarse pitch casing thread connection.

Background technology

Along with the development of petroleum industry, by land in the limited situation of oil field increment, oil development gradually to shallow sea, the sanidal Oil/gas Well development in deep-sea, ocean, because marine oil field operation wind effect factor is large, for heavy caliber sleeve pipe, common API screw thread easily causes being difficult for centering and causes thread alternating, and marine exploration and development cost is high simultaneously, and conventional API thread pitch is smaller, the spinner time is long, will save considerable expense if improve setting of casing speed.

At present, normally API knuckle screw joint or the partially trapezoidal joint of joint that tubing and casing adopts, the advantage of this nipple is technology maturation, easily processes and detects, but also having a lot of shortcomings simultaneously.Common API round thread bonding strength only has the 60%-80% of body yield strength, though the bonding strength of common API buttress thread approaches or to reach body intensity gas sealing ability inadequate, and easy pull-out failure while stretching for bigbore sleeve pipe.

Summary of the invention

For the problems referred to above, the utility model proposes a kind of coarse pitch casing thread connection, use after the utility model, its gas tightness is good, and can make the quick spinner of sleeve, difficult drop-off.

A kind of coarse pitch casing thread connection, its technical scheme is such: it comprises two tubing and casing, internal thread connecting piece, the end of described tubing and casing has external screw thread, on described internal thread connecting piece, have internal thread, described external screw thread from end to head end enlarging gradually, described in two ends, internal thread is from arranging to corresponding expanding end from described internal thread connecting piece middle part respectively, the end external screw thread of the corresponding described oil pipe cover that connects correspondence position of corresponding end internal thread of described internal thread connecting piece, the axis of described oil pipe cover and the axis of described internal thread connecting piece overlap mutually, it is characterized in that: described external screw thread is coarse thread, described internal thread is coarse thread, described coarse thread refers to that 1 inch of upper tooth number is 3 or 4 or 5 screw thread, the two ends of described inner thread piece are the plane of the axis of vertical described internal thread connecting piece, in described externally threaded inner side, tail end is provided with torque shoulder outside right angle, the corresponding end interference fit of torque shoulder and described inner thread piece outside the described right angle under screw threads for fastening state.

It is further characterized in that: the described external screw thread of per inch and described internal thread tooth number are 3;

The crest top land of each described external screw thread, internal thread is all parallel to the axis of described tubing and casing, and the tooth bottom surface of described external screw thread, internal thread is all parallel to the axis of described tubing and casing;

The angle of the screw thread bearing surface of described external screw thread, internal thread and the axis of described tubing and casing is 90 °, the acute angle angle of the screw thread spigot surface of described external screw thread, internal thread and the vertical line of described externally threaded axis is 30 °～35 °, and described external screw thread equates with the acute angle angle of the vertical line of the axis of described internal thread with acute angle angle and the described internal thread of the vertical line of described externally threaded axis;

The acute angle angle of the vertical line of described externally threaded screw thread spigot surface angle and described externally threaded axis is 35 °, and the acute angle angle of the vertical line of the screw thread spigot surface angle of described internal thread and the axis of described internal thread is 35 °.

Adopt after the utility model, owing to fine thread being changed to common API buttress thread into coarse thread, so just improve make-up speed, at the bottom of screw thread tooth top, tooth, be parallel to axis rather than bus simultaneously, convenient while making button, be not easy to occur thread alternating, so just saved the connect hours, thereby just can reduce expenses; Due to the end close contact of torque shoulder and inner thread piece outside the right angle of tail end in tubing and casing, form interference fit, make torque wrench moment Main Function in torque shoulder, so just improve the ability of joint joint efficiency and stress corrosion resistant outside right angle, play good hermetic seal effect simultaneously.

Accompanying drawing explanation

Fig. 1 is structural representation of the present utility model;

Fig. 2 is screw thread enlarged drawing of the present utility model.

The specific embodiment

As Fig. 1 and Fig. 2, a kind of coarse pitch casing thread connection, its screw element comprises two tubing and casing 1 and an internal thread connecting piece 2, the axis 11 of tubing and casing 1 and internal thread connecting piece 2 overlaps, the front end of tubing and casing 1 has external screw thread 5, on internal thread connecting piece 2, two ends have internal thread 4, external screw thread 5 is from end enlarging gradually to the inside, internal thread 4 is arranged to corresponding expanding end from described internal thread connecting piece middle part respectively, the end external screw thread 5 of the corresponding end internal thread 4 corresponding tubing and casing 1 that connect correspondence position of internal thread connecting piece 2, the two ends of internal thread connecting piece 2 are the plane of the axis 11 of vertical internal thread connecting piece 2, be provided with torque shoulder 3 outside right angle at the inner side of external screw thread 5 tail end, end interference fit under tightening state of torque shoulder 3 and internal thread connecting piece 2 outside right angle, external screw thread 5 and internal thread 4 are coarse thread, and the tooth number on its per inch is 3, external screw thread 5 and internal thread 4, the crest top land 9 of its screw thread is all parallel to axis 11, the tooth bottom surface 10 of screw thread is all parallel to axis 11, its screw thread bearing surface 6 is 90 ° with the angle of the axis 11 of screw element, and the screw thread spigot surface 7 of screw thread is 35 ° with acute angle 8 angles that the vertical line of the axis 11 of screw thread forms.

Claims

1. a coarse pitch casing thread connection, it comprises two tubing and casing, internal thread connecting piece, the end of described tubing and casing has external screw thread, on described internal thread connecting piece, have internal thread, described external screw thread from end to head end enlarging gradually, described in two ends, internal thread is from arranging to corresponding expanding end from described internal thread connecting piece middle part respectively, the end external screw thread of the corresponding described oil pipe cover that connects correspondence position of corresponding end internal thread of described inner thread piece, the axis of described oil pipe cover and the axis of described internal thread connecting piece overlap mutually, it is characterized in that: described external screw thread is coarse thread, described internal thread is coarse thread, described coarse thread refers to that 1 inch of upper tooth number is 3 or 4 or 5 screw thread, the two ends of described inner thread piece are the plane of the axis of vertical described internal thread connecting piece, in described externally threaded inner side, tail end is provided with torque shoulder outside right angle, the corresponding end interference fit of torque shoulder and described inner thread piece outside the described right angle under screw threads for fastening state.

2. a kind of coarse pitch casing thread connection according to claim 1, is characterized in that: the described external screw thread of per inch and described internal thread tooth number are 3.

3. a kind of coarse pitch casing thread connection according to claim 1 and 2, it is characterized in that: the crest top land of each described external screw thread, internal thread is all parallel to the axis of described tubing and casing, and the tooth bottom surface of described external screw thread, internal thread is all parallel to the axis of described tubing and casing.

4. a kind of coarse pitch casing thread connection according to claim 1, it is characterized in that: the acute angle angle of the screw thread spigot surface of described external screw thread, internal thread and the vertical line of described externally threaded axis is 30 °～35 °, described external screw thread equates with the acute angle angle of the vertical line of the axis of described internal thread with acute angle angle and the described internal thread of the vertical line of described externally threaded axis.

5. a kind of coarse pitch casing thread connection according to claim 4, is characterized in that: the angle of the screw thread bearing surface of described external screw thread, internal thread and the axis of described tubing and casing is 90 °.

6. according to a kind of coarse pitch casing thread connection described in claim 4 or 5, it is characterized in that: the acute angle angle of the vertical line of described externally threaded screw thread spigot surface angle and described externally threaded axis is 35 °, the acute angle angle of the vertical line of the screw thread spigot surface angle of described internal thread and the axis of described internal thread is 35 °.