CN2339740Y - Petroleum case pipe - Google Patents

Abstract

The utility model relates to a petroleum casing pipe and the screwed joint structure thereof, which is suitable for repairing old wells. The utility model is composed of a pipe body and a pipe joint hoop. A screwed buckle is round shaped, or deflective trapezoid shaped. The diametral conicity of screw threads is 1: 16. The outer diameter of the pipe body is less than 114.3 mm. The outer diameter of the pipe joint hoop is less than 115 mm. The size model and the strength of the utility model can meet the requirements of well conditions on oil fields. Although the size is minified, the mechanical property can still meet the requirements. The wall thickness of the pipe body and the joint hoop which has a same outer diameter can be made with 3 to 4 stage size. Besides, API standard descent tools and repair tools can be used.

Description

Petroleum casing pipe

The utility model relates to a kind of petroleum casing pipe and threaded joints structure thereof, is specially adapted to use when old well is repaired.

The petroleum casing pipe that uses in the prior art is all according to the API standard production, external diameter is all greater than 4 1/2 inches (114.3mm), specification such as 41/2,5,51/2,7 inch is arranged, development along with petroleum industry, the needs of especially old well reparation and other special hole condition, the oil field requires to use the sleeve pipe less than 114.3mm, the also untapped production at present of the sleeve pipe of this part specification.

The purpose of this utility model is to obtain a kind of specification less than the API standard (petroleum casing pipe of external diameter＜114.3mm), its dimensions can satisfy the needs of hole conditions such as old well reparation, and structure, intensity satisfy the requirement of oil field hole condition, and can use the following well tool and the fix tool of API standard.

For achieving the above object, the technical scheme that the utility model proposes is such:

A kind of petroleum casing pipe is made up of body and pipe box cupling, and its screw-thread form is round thread or trapezoidal partially, and screw thread is 1: 16 at diametric tapering, the body external diameter is less than 114.3mm, the wall thickness t=(D-d)/2 of its body, and D is a tube outer diameter, d is an ips, and the box cupling external diameter is less than 115mm

The hand-tight place of body screw thread pitch diameter

L ₁For pipe end to hand-tight face length degree, L ₂Be effective thread length, L ₂Be body screw thread end point length, D ₄Be end body outside diameter,

The screw thread pitch diameter E of the hand-tight place of box cupling ₁Tg25 ° of=Q-2 (M-q), Q are the box cupling bore diameter, and q is the box cupling boring depth, and M is the length of hand-tight plane of action position to coupling face,

Coupling length N _L=2 (J+L ₁+ M+PA)+Δ, wherein J be the tight back of machine body end face to box cupling centre distance, Δ is an adjustment factor, P is a bonding strength, A is hand-tight tight apart from the tooth number,

Body and box cupling are when same external diameter, and its wall thickness is 3～4 different values.

Below in conjunction with accompanying drawing the utility model is described in detail.

Fig. 1 is the whole connection layout of the utility model petroleum casing pipe nipple.

Fig. 2 is of the present utility model being threaded and fiting relation figure.

Little external diameter of the present utility model (less than 114.3mm) petroleum casing pipe is old in the oil field When repairing, uses in well, according to the requirement of hole condition, although the external diameter minimizing, in use The technical indicators such as the load type of bearing, complexity, the density of load and reliability can not Decrease, should keep reaching or approaching the applying working condition level that reaches the heavy caliber sleeve pipe, Be subjected to the comprehensive functions such as stretching, internal pressure, external pressure, bending, distortion in the use procedure Lower, make body itself and jointing have enough intensity, to guarantee body box cupling spiral shell The tubing string that line is tied is in the structural intergrity of the dark down-hole of several kms. Simultaneously, also should Guarantee that tubing string has enough sealings under the atm difference long term of hundreds of MPa. This The sleeve pipe that external diameter is littler does not provide the parameter of these models, as presses API in the API standard The major diameter sleeve pipe is analogized, and its structure and size all can not satisfy the requirement of oil field hole condition, Need redesign to calculate relevant parameter.

The utility model by plasticity and finite element theory to the relative dimensions of sleeve pipe and several What parameter is calculated, and structure such as Fig. 1,2 of obtaining petroleum casing pipe show.

Among Fig. 1,1,3 is body, and 2 are the pipe box cupling, and L is body length, gets 4～15 meters, Can require fixed concrete size according to the oil field. N_LBe coupling length, N_LThe determining of value satisfying under the bonding strength, determines according to wall thickness and the external diameter value of box cupling, generally gets N_L=177.8～150mm. W is the box cupling external diameter, repairs for satisfying the requirement of old well, for oil well pipe Large scale, W＜117mm.

Among Fig. 2, L₁Be extremely hand-tight face length degree of pipe end, for one section reach of self-assembling formation in the processing, for guaranteeing necessary bonding strength, get L₁=43.18～48.7934mm。

L ₂Be useful thread, screw thread is anti-tries to shirk responsibility to calculate to be worth with this and is as the criterion, and gets L₂=50～ 68mm。

L ₄Be body run out of thread length, wherein L₂And L₄Between the general incomplete thread of screw thread self-assembling formation when being the chaser cutter lifting, this section screw thread has black skin buckle, gets L₄=60～ 75mm。

M is the length that coupling face is arrived in hand-tight plane of action position, span 12～18mm.

Q is the box cupling boring depth, span 13～6mm.

A is hand-tight compact distance tooth number, i.e. the button number of hand-tight rear thread exposed junction, and value 2～4.

D ₄Be end body outside diameter, for not thickening pipe end D ₄D is identical with tube outer diameter, for extra strong pipe D ₄Greater than D, can improve its anti-ability of trying to shirk responsibility by thickening for light-wall pipe.

Q is the box cupling bore diameter, forms the spigot surface when connecting, its span 60～105mm.

E ₁It is the hand-tight place of body screw thread pitch diameter.

The J value be the tight back of machine body end face to box cupling centre distance, come standard to twist the relay square and the position that is threaded with this, and guarantee rational bonding strength.

T is the body wall thickness.

Size Control model of the present utility model is:

The wall thickness t=(D-d)/2 of body, (1)

The hand-tight place of body screw thread pitch diameter

The screw thread pitch diameter E of the hand-tight place of box cupling ₂Tg25 ° of=Q-2 (M-q), (3)

Control principle: E ₁=E ₂

Coupling length N _L=2 (J+L ₁+ M+PA)+Δ, (4)

P-pitch.Every cun 8 button, p=3.175mm,

Every cun 10 button, p=2.54mm,

Δ-adjustment factor, span: 0～2.84mm.

L ₄-L ₂=7.239+Δ， (5)

L ₂-L ₁=20.1676+Δ。(6)

Formula (1)～(6) constitute the size Control model.

In order to guarantee required intensity, petroleum casing pipe of the present utility model adopts following size checking computations model to check, and can guarantee that in size its intensity still meets the demands during less than conventional parameter:

Bonding strength $P=0.95A\·L\·[\frac{0.75D^{-0.59}{U}_P}{0.5L+0.14D}+\frac{Y_P}{L+0.14D}],----\left(7\right)$

L=L wherein ₄-M, (8)

U _pBe body material least limit intensity, Y _pBody material SMYS, $A=\frac{\mathrm{\π}}{4}[{(D-0.626P+2.1778)}^2-d^2].----\left(9\right)$

Bonding strength p 〉=[P _Allowable] (oil field allowable value) (10)

Verification box cupling intensity: P _j=0.95A _jU _P(11) $A_j=\frac{\mathrm{\&pi;}}{4}[W^2-{(E_1-\frac{{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="Y9820281400081.png"\; state="\{\{state\}\}">L</figure-callout>}}_1}{16}+0.626P-0.1778)}^2]----\left(12\right)$

U wherein _PBe pipe box cupling material least limit intensity,

Require P _j=(1.3～1.7) P (bonding strength) (13)

Limit internal pressure during use in the oil field: $P_s=\frac{{\mathrm{\&sigma;}}_S}{2}(1-\frac{a^2}{b^2})----\left(14\right)$

Wherein $b=\frac{D}{2}----\left(15\right)$ $a=\frac{D}{2}-t----\left(16\right)$

Formula (7)～(16) constitute intensity verification model jointly.

Dimension model with 4 inches (101.6mm) round thread sleeve pipes is that example is introduced embodiment of the present utility model below.

Present embodiment is a standard round screw thread button-type, and the tapering of screw thread on diametric(al) is 1: 16.

Box cupling is of a size of:

External diameter W ₂=114.3mm (41/2 inch),

Bore diameter degree of depth Q ₂=103.98mm (4.09375 inches),

Box cupling boring depth q ₂=12.70mm (1/2 inch),

Hand-tight engagement is put down and position M ₂=17.88mm (0.704 inch),

Chamfering is 0.5 * 45 ° in the box cupling, 1.0 * 45 ° of the outer chamferings of box cupling.

Body is of a size of:

The body outer diameter D ₁=101.6mm (4 inches),

Pipe end is hand-tight length L extremely ₁=45.618mm (1.796 inches),

The effective thread length L ₂=65.786mm (2.59 inches),

Pipe end is to end point full stand of thread L ₄=73.025mm (2.875 inches),

Minimum length L from the full top of pipe end face screw thread _c=44.45mm (1.75 inches),

Locate middle footpath E for hand-tight ₁=99.146mm (3.90337 inches),

Hand-tightly closely count A=3 apart from tooth,

The tight rear end face of machine is to box cupling centre distance J=12.7mm (0.5 inch),

The body wall thickness is divided into 3 grades according to the operating mode difference,

Model 1t ₁=6.35mm (0.25 inch)

Model 2t ₂=7.366mm (0.29 inch)

Model 3t ₃=8.382mm (0.33 inch)

Constitute three kinds of products, its internal diameter of tube body is respectively:

d ₁=D-2t ₁=101.6-2×6.35=88.9mm

d ₂=D-2t ₂=101.6-2×7.366=86.868mm

d ₃=D-2t ₃=101.6-2×8.382=84.836mm

The utility model is to be processed with conical external screw thread at tubing and casing body two ends, be connected to form the sleeve pipe tubing string by a box cupling (two ends are processed with the inside tapered thread with the outer-diameter threads coupling), the wall thickness of box cupling and physical dimension and male-pipe body form corresponding relation, the screw thread button-type is the round thread or the buttress thread of API standard, for body, the box cupling of same external diameter, the size of wall thickness is got 3～4 grades by oil field operating mode difference.

Compared with prior art, its size of petroleum casing pipe of obtaining of the utility model is less than API Standard specification, but its dimension model, intensity satisfy the requirement of oil field hole condition, and can use API Lower well tool and the fix tool of standard.

Claims (2)

1. petroleum casing pipe, form by body [1] and pipe box cupling [2], its screw-thread form is round thread or trapezoidal partially, screw thread is 1: 16 at diametric tapering, it is characterized in that: the body external diameter is less than 114.3mm, the wall thickness t=(D-d)/2 of its body, D is a tube outer diameter, d is an ips, and the box cupling external diameter is less than 115mm

The hand-tight place of body screw thread pitch diameter

L ₁For pipe end to hand-tight face length degree, L ₂Be effective thread length, L ₂Be body screw thread end point length, D ₄It is end body outside diameter.

The screw thread pitch diameter E of the hand-tight place of box cupling ₁Tg25 ° of=Q-2 (M-q), Q are the box cupling bore diameter, and q is the box cupling boring depth, and M is the length of hand-tight plane of action position to coupling face,

Coupling length N _L=2 (J+L ₁+ M+PA)+Δ, wherein J be the tight back of machine body end face to box cupling centre distance, Δ is an adjustment factor, P is a bonding strength, A is hand-tight tight apart from the tooth number.

2. petroleum casing pipe according to claim 1 is characterized in that: described body and box cupling are when same external diameter, and its wall thickness is 3～4 different values.

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