JPS58193993A - Pipe joint for oil well pipe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention makes it possible to improve oil country tubular goods used for extracting crude oil and natural gas produced underground.

The depth of wells that produce crude oil is up to several thousand meters, but in recent years the depth has been increasing more and more, reaching more than 6000 meters. Oil well W#1 is connected using many W-Tokura. The strong storm that is demanded by this VC is a mighty pull! jH
It should be able to withstand IJ weight well and maintain a certain airtightness 1 without leaking the internal S fluid. The depth of the well is 1000m, and the depth of the well is 1000m
However, even if you keep in mind that the oil well type m lid is usually several tens of Kp per meter,
Needless to say, this is applied in a continuous manner as the depth of the well LD increases. Due to these circumstances, the recommendation '4I regarding oil country pipe fittings is that
Along with the history of l-adic, many (things) have been announced.-
When the number of squares of f: is specified -r, Japanese Patent Publication No. 35-7630, Publication No. 11836-5236, Japanese Patent Publication No. 11836-1
Publication No. 742, Special Publication No. 41-6421, Special Publication No. 4
5-18096 Publication, Special Publication No. 52-11765, Special Publication No. 52-27367, Historically #US Special Publication F+
No. 2907589 'dl14mtb, US special Jf 2nd
980451 zu 114 specification and wood country mochi d to No. 29920
Taisho etc. for No. 19 vcIk! , and can list nine joints. Among these, the one that is often used is the known joint shown in Figure 1 K.

In Fig. 1, there is shown an H/1W joint lamp, in which qltC and C are threadedly connected from one end to a coupling 8 having a cylindrical outer 112 shape. The eight couplings tloK are formed so that their diameters become smaller as they proceed from both ends in the axial direction toward the ends. A buttress-type internal thread with tapers A and P, based on engineering standards, is inserted, and a shoulder B is formed in the center of the inner body. On the other hand, kai c and cVc have a female thread of coupling 8 and a -1 taper buttress fiber thread carved in their ends, and coupling 8 and '
etc., c and t are strongly screwed together. Its seal structure 4t
This is shown in FIGS. 2 and 3. Figure 2 #'i
The cross section on the left side of Figure 1 is enlarged and blown out, and the 3rd t
1! J is shown enlarged to * in the circle S in Fig. 2.

As seen in the 3rd tgK, coupling A and '@OV
At c, the female thread and the male thread are cut and stopped, and 7 is ahead of the part (to the right) K#''i, both of which are approximately 2 to 3 threads r (a flat thread with no corresponding thread [10D, l is provided) This inclination Ij [ID, illusion, buttress screw and 1-L
(It has a taper of 1/i6. Coupling 8 #
1lI4drt Where D ends on the right side, the shoulder B is connected to the opposite FK bond, and where the slope ml of 'kc ends on the right side, '#1 point is connected to the G side, and the impact side F is also connected. Leakage 1
1G4 is equally steep on the inner surface of tube C at tab.

When coupling 8 and '#to are screwed together and tightened with Power Tight, first the #1 surface and E come into surface contact, and then the abutment 1 and the tube end surface G also come into contact. When the torque of the power tight reaches a predetermined value t, the screw connection between the coupling 8 and the actual C is completed. At that time, KFi applied a strong compressive stress to the interface between the inclined surface and the mouse, between the connection between the F and the blind end 1iUG, and the Kama Kaede thJ Roasted Metal We pray that the city will be sealed in an airtight manner.

By the way, the voice II-JW (buried friend Katsubringum and government CVC#, the tension phrase iT (5o ~ 10ooton) between the white arrow direction shown in Figure 3 VC and the black arrow Hj7+
The same internal pressure P (l ooo~zoooh! //cjlI
''), and it is unavoidable that the repeated vibrations Uj will be applied.7 As a result, the threaded portions of the coupling A and the coupling C will gradually deform, and the sloped peaks D and 21 and
The surface pressure toward the metal wheel due to the impact 1 button F and the blind end uIIG decreases, and finally, the first pressure H shown in Fig. 4 Vζ is generated.
In addition, the couplings A, 1 & C, which had been firmly attached at the initial stage of burial, were once again buried deep in the well. It is impossible for this to be narrowed, so it is also impossible to restore airtightness to the joint that loosened during use.

The present invention has been made with the purpose of solving the drawbacks of conventional Miya joints such as fjIJki.
Temporary W(, It Ptj kC) Even if the contact pressure of the metal seal l decreases due to C or a first seal occurs, a springback force is applied to the metal seal to automatically close and seal the first seal. However, I always try to keep it airtight.

The following is a diagram of a meeting for one issue [based on the example shown in 1 o VC]. The main part of the present invention is the seal 411Jli with the sparrow surface vs. the gold and the music! The seal is secured near the shoulder of the cup link and near the blind part 14 that screws into the coupling, so the rgi+ used below
Also, only the main parts are shown enlarged. There is no difference from the conventional joint shown in FIGS. 1 to 4 in terms of the overall external shape and the threaded parts.

The fifth example is the first embodiment of the present invention, in which the coupling 1 and the blind 2 are screwed together with hand tight L, leaving room for tightening with HK power tight and showing ffi type 1+. . It is the shoulder part in the center of the 3Fi coupling 10, and its side part is 4 on the impact surface, so it is 4i on the impact surface!
Some are perpendicular to the central axis, while others are arcuate, but in this case, the angle of repose #L is approximately 8 f. Between the abutting surface 4 and the threaded portion 7 [is,
Thread taper and diversion. There are 7 gushers and 5 ridges that are tilted with bones. On the other hand, 1 of 2Fi, -t
The end of the illumination screw is cut and stopped, and the part ahead of the friend part (on the right side) is a lip part 6, and the lip part 6 has a lip seal surface 7 40 that corresponds to the coupling '/'/- rule 1445. There is a lip end lR18 corresponding to the tip r (Fi scrap shoulder part 111114).This lip end 1sFi
It was set at right angles to the public axis. The high airtight seal of the public joint must be ensured by mutual pressure contact between the abutment surface 4 and the coupling seal surface 5, and the lip seal surface 7 and the lip end 111g. Must be able to finish at 8 or above. Reference numeral 9 denotes a slit which is a minimum gap of 14 m3 and is bored perpendicular to the public axis. This slit 9 is the impact surface 4
Ni'! ! This is a companion piece that causes elastic deformation in the scrap joint part 10 when a pressing force in the direction of the tQ line is applied. In this embodiment, the slit 90 has a width of 0.2 to 0.5 cm and the slit 011 is a slit formed in the lip s6 at right angles to the central axis and has a minimum width of 7. This slit 11 also has a lip direction 81 similar to the slit 9 of M&IS3.
When the C pressing force is applied, the lip edge portion 12. to%
The gap is similar to the slit 9 of the shoulder part 3, and the depth of the slit 9 is dl, the depth of the slit 9 is dl, the slit 11 is the same as the slit 9 of the shoulder part 3.
1DIIa''g and the thickness of the lip edge portion 12 are both determined based on the thickness tt of the end portion of the lip portion 6.

”1- dx * ble ban each tEJ t
t T Terror, 6 c.

The thickness tFiF2O3 of the end of the lip s6 is 3=100. The slits 9 and 11 are preferably formed by laser machining or electrical discharge machining. In this example, we will focus on electrical discharge machining from the perspective of eel and workability. In this case, Surin) f
It is preferable to form an angle at the bottom of J # 11 to avoid stress concentration. Note that it is slightly smaller than the angle t at the 6th end of the 11ii 1 capital.

The vicinity of the shoulder s3 and the vicinity of the lip portion 6 are as shown in iIQ.
Since Vt is applied to the coupling l and -tt 2 #-t, the screw and shaft are screwed and screwed together using power tight with a predetermined torque. When PowerTight tightens &j, the lip portion 6 is tightly fitted to the coupling seal tlu 5 K, and the blood pressure between the coupling seal surface 5 and the lip seal surface 7 gradually decreases to KIllt+, and the lip From the point where the end face 8 touches the yoke 4vζ, the scrap edge m1oij 1 lip edge 1+s 12 is elastically deformed to the left, and the internal VC elastic energy of each is stored, and the scrap edge ml is deformed to the left.
9. The opening of 11 is closed IIk, the torque of Power Tight reaches the predetermined maximum value, and the coupling seal [k]5
The pressure between the contact surface 4 and the lip seal surface 7 becomes large, and the pressure between the contact surface 4 and the lip seal surface 7 becomes large, and the coupling
The screw connection between the and the official 2 is completed. FIG. 6 shows a state in which the screw connection is completed.

By doing this, when the screwing of the Power Tight Iik Rib is completed, Kt-j, the scrap edge part 10 and the lip edge 1is
Since elastic energy is stored inside 12,
The seventh public joint is buried deeply in the well P (11), and is subjected to a tensile force T and internal pressure P, which is applied to the coupling seal surface 5, negative contact surface 4, and lip 7-17. and the surface pressure between the lip direction 8 and the surface pressure 7t9, their relationship Kid
Will it create a relationship? (Even if the effect is 9, the shoulder edge capital 10
And the lip edge part 12Fi exhibits a springback phenomenon accompanying the blood pressure drop and Ichinoseki generation effect described in 1 above, and gold 1!
The initial sealing effect of Power Tight can be maintained for a long time and reliably without deteriorating the sealing condition due to 4th1 versus gold-1K.

7 and 8 are according to the second embodiment of the present invention! This shows the joint structure. In this embodiment, the impact a of the shoulder portion 3 is
ll124' is arc-shaped, and the lip end dD28t- of the lip part 6 is also arc-shaped, and the lip part 6 has an arc-shaped slit 2.
1' is drilled, and a slit t? is made in the scrap g3. I will not set up an arc-shaped half of 7 to 24 for the time being! The thickness of B is approximately equal to the thickness of the end of the lip s6, and the thickness of the arcuate half pole of the lip direction 28 is approximately 1.5 times that of the arcuate half pole of the impact surface 24. The distance between the arcuate slits 21 is larger than that of the first embodiment, and 1
-211I+, and the depth 4 of the arcuate slit 21 and the width - of the lip edge 22 were both about 12 times the thickness of the 6th end of the K17 tap part. These dimensions Fi are determined appropriately by considering the outer diameter and wall thickness of #'i, the yield strength associated with the material @Vc, and NtJix!, - 1! The dimensional relationship of R is strictly specified and not precise. In addition, the arc-shaped Slin) 21tie 3 K' Jl dk L The opening of the arc-shaped sulin (21) is closed, the lip edge portion (22) is deformed, and the lip edge (I) button (28) is completely deformed. The curvature corresponds to the curvature of k124, and they are pressed against each other.

Next, the sealing effect of the pipe joint according to the present invention is shown in FIGS. 1 to 4, and the results of a comparison test with a conventional public joint will be explained. Table 1 shows the P-, F, and IM grades tested.
110, N-80, and 0-75. The dimensions and test internal pressure of the steel pipes for each clade are also shown. The 2nd FI is a link between the steel engineers listed in yIJ and a cup link manufactured based on the same M, P, and engineering standards, and a tensile test is performed on the steel members.

Table 1 2* Table 2 KJL (According to the pipe joint according to the present invention, even if the pipe joint is applied in both axial directions until it breaks, internal pressure water will not leak and the water will not leak 7tO Pipe fittings of the United States,
In both cases, there was a water leak near the 60th station of the broken vIjT station.

As described above, the public coupling of the present invention has the inner th of the coupling.
I is provided with a nine-shoulder part, and a lip part 7t provided on a part of the bolt that is screwed into this coupling is provided with a slit in the direction perpendicular to the axis of the force Kv. Then, form the elastically dredged scrap edge and the lip edge, and when the coupling and the bolt are screwed together with power tight, elastic energy is transferred to the shoulder edge and the lip edge. Since the button is used to form a pressure seal between the gold maple surface and the gold maple surface in a fixed state, the blood pressure that does not change at all times acts on the gold maple seal surface KVi, so that the tightening by Power Tight is completed. The sealing effect holds the pipe long and reliably, and the sealing effect does not deteriorate even if the pipe joint is subjected to strong tensile charges and internal pressure.

Figures 1 to 4 show an example of a conventional government joint, and Figure 1 is a cross-sectional view of a pipe joint.
Figure 2 is an enlarged view of the left side of Figure 1 in the forward direction, Figure 3 is an enlarged view of the circled area in Figure 2, and Figure 4 shows the large axial drag angle and internal pressure in the joint. Seal [111K i Ib]
Figures 5 to 8 show Embodiment 1 of the pipe joint of the present invention, and Figure 5 is part 11 of the 1st embodiment, and the hand tight tightening was performed in the autumn of time IIN'. The cross-sectional view shown in Fig. 6 shows the condition when the one in Fig. 5 is power-tight and the pongee mating 7 is applied. Cross-sectional view showing the condition m1 when tightening the tie F.
FIG. 8 is a diagram showing the same as shown in FIG. 7 with Power Tight and timely tightening shown in m1.

l...Coupling 2...Pipe 3. ...shoulder area
4... Impact - 5... Coupling seal l 6...
・Lip part 7...Lip seal III] 8...Lip direction 9...Slit 10...Shoulder edge $
11...Slit 12...Rip Edge Department Special Representative Sumitomo Metal Industries Co., Ltd. Agent Patent Attorney Unehiko Uchida Figure 1 Figure 2 Figure 8 Figure 5 Figure 6 Meeting Figure 7 Figure 8

Claims (1)

[Claims] 1. In a threaded joint for oil country tubular goods, a lip portion with a seal fi]t is formed at the end of the pipe into which a male thread is inserted, and! II]k! , a shoulder portion having a sealing surface that comes into close contact with the sealing surface of the lip portion is formed at the inner depth S of the coupling in which a female thread for screwing the pipe is formed, By drilling a slit in the direction approximately perpendicular to the tube axis direction, an elastically deformable lip edge portion and/or shoulder edge portion is formed, and the tube and the coupling are completely screwed and tightened. An oil well w rough pipe joint, characterized in that the lip edge portion and the shoulder edge portion store elastic energy and form a metal surface-to-metal surface seal between them in a t state.