JPS61289915A - Manufacture of strainer pipe - Google Patents

Abstract

PURPOSE:To improve performance and strength of a straiiner pipe and to reduce production cost by winding spirally a long-sized metallic material formed projections with a prescribed interval then welding the contacting projections of an adjacent loops. CONSTITUTION:The long-sized metal strip 2 excellent in corrosion resistance and strength is provided and the projections 1 are formed on both sides or one side of the strip by cutting, etc. At this time, the shape of removing parts of the metal strip 2 is determined in accordance with the required ratio of an aperture as the removed parts are formed to slits 4 after the pipe is completed. Then, after chambering edge parts 5, the metal strip 2 is wound in loops and the projections 1, 1 of the adjacent loops are welded. After that, the pipe material is cut in a prescribed length, then the closing members and connecting members are fitted to make products. In this way, the through holes 4 are chambered and the man-hour is reduced. Therefore, the performance and strength are improved and the production cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for manufacturing strainer pipes used in various wells such as oil wells, gas wells, water valves, and geothermal wells.

<Conventional technology> In extraction wells for extracting oil, gas, water, geothermal heat, etc., wells that efficiently collect the fluid to be extracted and prevent valve walls from collapsing and rock cover from blowing out are used. For this purpose, a so-called strainer tube with a large number of through holes formed in the peripheral wall is used. In addition, pressurized fluids are injected for recovery of oil and gas wells, condensed water is returned to the ground after being used for geothermal power generation, mortar for ground improvement, and water glass is injected. This strainer tube is also used in injection wells for Figures 4 (A) to (F) show the side shape of a conventional strainer tube, Figures 5 (A) to (F) show the cross-sectional shape of each axis of the tube in Figure 4, and Figures 6 (A) to (F). ) also shows the axial cross-sectional shape.

(A) is a hole with a round hole formed as a through hole, (B) is a hole with an oblong hole in the axial direction. (C) is a hole with a notch in the direction of the tube, and is in line with the axis of the tube. Some have cuts at right angles, while others have cuts at an angle.

In), one side of the notch made in the circumferential direction is pushed into the inside of the tube, and in (e), the entire portion between the notches is pushed into the inside of the tube. In addition, (f) is a tube having a triangular cross-section, which is wound spirally at regular intervals, and an axial connecting rod is welded to the inner side of the spiral. The solid arrows in Figure 6 indicate the flow of fluid when used in a sampling well, indicating the flow direction from outside the pipe to the inside of the pipe, and the dashed arrows indicate the flow of fluid when used in an injection well, from inside the pipe to the inside of the pipe. Indicates the direction of outward flow.

Traditionally, the manufacturing of these strainer tubes has been carried out by (a) (b)
For (c), the tube body is perforated, and for (c), it is a tube.

For (e), the tube body is subjected to cutting and press processing, and for (f), the threads are wound into a spiral shape as described above, and then connected by londra welding after death. Both were carried out separately.

[Problem that the invention seeks to solve]

Generally, in a strainer tube, if the resistance when fluid passes through its through holes is large, the fluid collection and injection capabilities will naturally be reduced. Also, in this hole,
It is said that cavitation erosion occurs, which destroys the tube and significantly shortens the life of the well. The former pressure loss is caused by flow separation and vortex formation that occur at the edge of the hole, and the latter, cavitation erosion, is caused by cavitation due to the pressure drop caused by the vortex generated at the edge of the hole. occurs,
This is considered to be the cause of the collapse of the pressure recovery due to the expansion of the flow path after passing through the hole a, causing the erosion to proceed. Therefore, in order to prevent these phenomena in the through hole, it is considered effective to chamfer the edges of the through hole on both the fluid inlet and outlet sides. However, the conventional J! ! ! In the construction method, a strainer tube with chamfered edges on both sides is used. It is not easy to build one.

For example, in (a) and (b), in which the tube is manufactured by drilling holes, chamfering the outer surface of the tube is still easy, but chamfering the inner surface of the tube is extremely difficult. Regarding (c) to (a) where the through holes are formed by cutting or press working, the chamfering process on the inner surface of the tube is also circular. Not yet (ha)
It is possible to manufacture products with no edges on both sides by selecting the cross-sectional shape of the steel bar, but even if chamfering is possible, the connecting rod installed inside the pipe will cause pressure loss, etc., and it will not be as long as expected. effect cannot be obtained.

Thermal theory, in this (c), if the connecting iron is made thinner, pressure loss etc. will be improved, but at the cost of this, the strength in the tube axis direction will decrease, and in geothermal wells used under high temperature and high pressure, 1 will shorten the lifespan. invite.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for easily manufacturing a high-performance strainer tube with chamfered edges on both the inner and outer surfaces of the tube without deteriorating its strength.

[Means for solving problems]

In the method of the present invention, a long metal material having protrusions at predetermined intervals on at least one side is wound in a spiral shape so that the protrusions contact adjacent loops, and the contact portion 'fcR
The feature is that the strainer tube is in J contact with a slit between the protrusions.

That is, according to the method of the present invention, a cut portion that becomes a slit is formed in a long metal material as a raw material at the stage of a straight material before being spirally wound, and chamfering is also performed at this stage. Therefore, a chamfer can be easily provided on the inner surface of the tube. After winding and forming, the adjacent loops are all directly welded to form a pipe body, and the members corresponding to the connecting rods of the strainer pipes in Figures 4 to 6 (f) are not used. , sufficient strength in the direction of the tube axis can be obtained, and there is almost no pressure loss or the like.

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

Figure 1 shows rectangular piece-shaped protrusions (1
) is spirally wound so that the protrusions (1) (11) of adjacent loops are in contact with each other.

Here, as the material for the long metal material (2), steel or non-ferrous metal with excellent corrosion resistance and strength is used. Specifically, stainless steel, alloy steel, Inconel, Monel, Hastelloy,
Titanium etc.

To form the entire protrusion (1), both sides of the material are removed by cutting or the like, leaving only the portion that will become the protrusion (1). Removal part (3)
The slit (4) (through hole) is removed after the strainer pipe is completed, and the ratio of the removed portion to the total area of the material determines the porosity of the strainer pipe, so it is necessary to adjust the porosity to the required porosity. The width, length and pitch of the removed portion (3) must be determined accordingly.

Both edge portions (5) (5) of the material sandwiched between both side removed portions (3) (3) are chamfered if necessary, but this processing is performed before the material is spirally wound. Therefore, both the inner and outer surfaces of the tube can be easily processed into a planar shape or a rounded shape.

FIG. 1 shows an example in which both edge portions (5) are chamfered to have a semicircular cross section.

For wound material, each protrusion (1
t(nki junction).

As for the welding means, resistance welding is preferable from the viewpoint of welding speed and bath welding deformation, but Ganu-arc bath welding such as M-G or TIG may also be used.

The welded tubular material is cut to a predetermined length as necessary, and a closing member is attached to one end and a connecting member is attached to the other end to form a product strainer tube.

Product dimensions are outer diameter 50~600M, wall thickness 2.0~16
．． It is customary to select a material with a length of 0 m, a length of 3 to 12 m, and a porosity of 8 to 50%.

FIG. 2 shows another embodiment of the present invention, and shows an example in which a long metal material (21) is used, in which protrusions (1) are formed at predetermined intervals on one side of a strip-shaped material.

In the above-mentioned example in Fig. 1, it is necessary to perfectly align the positions of the protrusions (1) (11) between adjacent loops during winding processing, and for this purpose, it is necessary to increase the processing accuracy and to make sure that the protrusions (11) are not yet aligned.
It is necessary to improve the spacing accuracy in step 1), but in the example shown in Fig. 2, the protrusion (]) comes into contact with the smooth side edge of the adjacent IV-P, so there may be some slight difference when forming the protrusion or during the winding process. There is an advantage that the accuracy error is acceptable.

However, if necessary, chamfering must also be performed on flat side edges without irregularities.

In addition, Fig. 3 shows an example in which a linear or rod-shaped long metal material (2) is used, and the protrusion (1) is a knot.
is provided.

As a manufacturing method for this material, the joints may be joined separately by welding, etc., but the material has an outer diameter that is approximately the same as the outer diameter of the joint, and the material is rolled, etc., leaving the part that will become the joint. The method of diameter reduction is recommended in terms of strength, accuracy, etc.

What is important in this example is that the slit (
4), it is necessary to avoid contact of nodes between adjacent loops as much as possible when the material is fully wound, and for this purpose, the interval t between nodes is determined so as to satisfy the following condition. It's good.

However, for welding a D strainer tube with a positive integer average diameter n, resistance bath welding, M work G bath welding, T work G bath welding, etc. are used as in the case of the examples shown in FIGS. 1 and 2.

In addition, as something similar to the example in Fig. 3, all the materials having the same outer diameter as the outer diameter of the part outside the part are crushed in one direction at a predetermined interval,
A method in which a hemispherical protrusion is entirely formed on one side may be used.

Furthermore, it goes without saying that a square bar or the like may be used in place of the round bar.

In the case of the example shown in FIG. 3, since the portion between the protrusions (1) of the elongated metal material (2) has a circular cross section, the effort of chamfering this portion can be omitted.

Both ends of the through hole (4) (slit) in the front direction do not have much influence on the movement of the fluid (as shown in Fig. 6, the fluid mainly performs a combined movement in the tube axis direction and the tube diameter direction). There are few advantages to chamfering 1.

In the method of the present invention, the production, winding, and welding of the material with protrusions may be performed in separate steps, or all or part of the steps may be performed continuously.

〔Example〕

A strainer tube with a length of aooox, an outer diameter of 89 mm, a thickness of 5.5 mm, and a porosity of 10% was manufactured by the method shown in Figs. 1 and 3, and in addition to these, Figs. When strainer tubes with the same specifications manufactured by the conventional method shown in a) to (f) are used in sampling and injection wells with an inner diameter of 185M,
A comparison was made regarding the resistance coefficient ζ for each through hole, the pipe friction coefficient χ for the Nutrana pipe as a whole, and the yield strength in the pipe axial direction. The resistance coefficient ζ was determined by the following formula.

However, PO: Measured pressure outside the Nutrainer tube (Pa) P1 Measured pressure inside the Nutrainer tube (Pa) ρ: Fluid density (kg/d) ■: Measured flow velocity at the through hole (%) The friction coefficient χ was determined as follows.

However, D = Inner diameter of the strainer (W) m: Measured value of average flow velocity in the strainer pipe (m/8) Measured value of pressure drop in the P strainer pipe (Pa) L: Pressure loss measurement length (m) All materials are carbon steel, and in the conventional example shown in Figures 4 to 6 (f), the outer diameter of the connecting rod is 4.0 M and 50 mm.
Tests were conducted on different types of strainer tubes (18 rods each).

All contact tests were performed with resistance contact, and in the tensile test, the third
There were no breaks 1 from the bath contact area except for the one shown in the figure.

The results are shown in the table.

In the conventional example, except for those shown in FIGS. 4 to 6 (f), it is virtually impossible to chamfer the inner surface of the tube due to the labor involved. Therefore, when used for injection with the chamfered side located on the fluid inlet side, the resistance coefficient value is generally high.

Although the resistance coefficient value of Matada (to) is smaller when used for injection compared to other conventional examples, the resistance coefficient value is lower because the connecting rod is located inside the tube and causes an increase in resistance. The friction coefficient value of the tube has not improved, and if you try to drastically reduce the friction coefficient value of the tube, you will have to make the connecting rod thinner, and as a result, the tensile strength in the tube axis direction will decrease. do.

On the other hand, the example of the present invention has particularly good tensile strength among the conventional examples as compared to the one shown in Figure 1 (see Figures 4 to 6).
A) Possesses strength comparable to (b)).

However, when comparing the resistance coefficient values, the pipe with a chamfer on the outside of the pipe shown in Figure 1 shows a lower resistance coefficient value than any of the conventional pipes when used for sampling, while the pipe with a chamfer on the inside of the pipe shows a lower resistance coefficient value when used for sampling. The one with chamfered inner and outer surfaces has the lowest resistance coefficient when used for injection than any conventional example, and the one with chamfered inner and outer surfaces has the lowest resistance when used for both sampling and injection. Holds coefficient values. In addition, the tube friction coefficient λ is also the same value as the conventional examples (a) to (c), so there is no problem.

Although the tensile strength of the tube in the axial direction of the tube shown in Figure 3 is still inferior to that of the tube shown in Figure 1, its resistance coefficient value is comparable to that of the tube with semicircular chamfers on the inner and outer surfaces of the tube shown in Figure 1. The pipe friction coefficient χ shows a value second only to that in FIG.

The reason why the pipe friction coefficient χ is inferior to that in Figure 1 is thought to be because the nodular large-diameter part as a protrusion causes pressure loss. It's not.

〔Effect of the invention〕

As is clear from the above description, the method of the present invention virtually ends the hole formation when the material is in a straight state before it is spirally wound, and chamfers the straight material. Therefore, it is easy to process both the inner and outer surfaces of the pipe, and since the holes are formed at the edges of the material, many holes are punched throughout the material and all of the peripheries of these holes are chamfered. After that, the number of processing steps is significantly less than when winding it in a spiral shape. In addition, since adjacent loops are integrated by close contact, sufficient performance is guaranteed in terms of strength. Therefore, according to the present invention, there are only a few strainer tubes with excellent performance.TEA can be performed, and excellent Nutley-%' can be supplied at a low price.

[Brief explanation of drawings]

1 to 3 are partially cutaway schematic illustrations of aspects of the method of the present invention, with FIGS. 1 and 2 being perspective views, and FIG. 3 being a side view. Figures 4 to 6 (A) to (F) are explanatory diagrams of the shape of strainer tubes manufactured by conventional methods. Figure 4 is a front view, Figure 5 is a cross-sectional view of the shaft, and Figure 6 is a shaft cross-sectional view. FIG. In the figure, 1: protrusion, 2: long metal material, 8: removed part, 4:
Through hole (slit), 5: Edge part.

Claims (4)

[Claims] (1) A long metal material having protrusions at predetermined intervals on at least one side is wound spirally so that the protrusions contact adjacent loops, and the contact portions are welded to form slits between the protrusions. A method for manufacturing a strainer tube, comprising forming a strainer tube. (2) The method for manufacturing a strainer tube according to claim 1, wherein the long metal material is a band-shaped material. (3) The method for manufacturing a strainer tube according to claim 1, wherein the long metal material is a rod having a circular cross section. (4) The method for manufacturing a strainer pipe according to claim 3, wherein the bar material has a knot-like large diameter portion formed as a protrusion.