Wire-wrapped screen

Abstract

The invention relates to a wire-wrapped screen (1) for filtering crude oil, natural gas, or water, comprising at least one tubular support structure made of support elements (6), at least one wrap wire (8) which is wrapped about the support structure, wherein the at least one wrap wire (8) and the support structure made of support elements (6) are welded together. According to the invention, the cross-sectional profile of each of the support elements (6) tapers outwards in a conical manner in the radial direction, and the support elements (6) are arranged relative to one another such that the support elements do not contact one another. At least the support structure and the at least one wrap wire (8) consist of boron-treated steel.

Description

[0001] Wound wire filter

[0002] The invention relates to a wound wire filter for filtering crude oil, natural gas or water according to claim 1, as well as a method for producing a wound wire filter according to claim 10.

[0003] Filters for filtering crude oil, natural gas, and water from reservoirs are known. These filters can lead to clogging, deformation, corrosion, or erosion of the filter. Therefore, there is a need to improve these filters and increase their service life.

[0004] The object of the present invention is therefore to provide a wound wire filter and a method for producing a wound wire filter which is improved and to provide a wound wire filter which is more robust and has a longer service life in use.

[0005] The features of claims 1 and 10 serve to solve this problem.

[0006] The invention advantageously provides that the cross-sectional profiles of the support elements each taper outwards in the radial direction and the support elements are arranged relative to one another in such a way that they do not touch one another, wherein at least the support structure and the at least one winding wire are made of boron-coated steel.

[0007] The present invention has the advantage that the wound wire filter according to the invention is significantly more robust and exhibits fewer corrosion and erosion phenomena during use. The wound wire filter also exhibits better flow properties, resulting in fewer blockages of the filter during use. Because the wound wire filter is made of boronized steel and the boron penetrates the material of the wound wire filter during the boronization process, the boron does not dissolve during use. The overall surface hardness is also improved.

[0008] The cross-sectional profile of the at least one winding wire can be tapered inwards in the radial direction.

[0009] For at least 50% of the surface area of ​​the wound wire filter, the minimum distance between two wound wire windings can be between 1 pm and 50 mm. This minimum distance can also be referred to as the slot width. The minimum distance depends on the grain size of the surrounding area from which the medium is to be filtered.

[0010] In this way, the filtration of crude oil, natural gas and water can be carried out optimally.

[0011] The minimum distance between two adjacent support elements may be greater than the minimum distance between two winding wire windings.

[0012] An inner, perforated tube can be arranged within the supporting structure.

[0013] Within the supporting structure, the perforated tube can also be treated with boron or made of boron-coated steel. The outer diameter of the wound wire filter can range from 30 mm to 300 mm.

[0014] The wound wire filter can be connected to a closure ring at at least one of the two ends, preferably welded.

[0015] The support elements and the winding wire can be made of stainless steel.

[0016] Furthermore, the invention provides a method for producing a wound wire filter, which comprises the following steps:

[0017] - Providing support elements made of steel, each having a cross-sectional profile that is tapered,

[0018] - arranging the support elements, wherein the support elements are arranged in such a way that the arranged support elements form the shape of a tubular support structure and the cross-sectional profiles of the support elements are each tapered outwards in the radial direction, wherein the support elements are spaced apart from one another and do not touch one another,

[0019] - Holding the support elements in the arranged form by means of a holding device,

[0020] - Providing at least one winding wire made of steel,

[0021] - Winding the winding wire around the arranged support elements held by the holding device,

[0022] - Connecting the winding wire to the support elements by means of a welding process,

[0023] - Removing the holding device,

[0024] Boronizing the wound wire filter. Boronizing can include the following steps:

[0025] - Placing the support elements and the winding wire connected to the support elements into a closed furnace,

[0026] - Heating in the presence of a borating agent.

[0027] During heating, the furnace can be heated to a temperature of 750 to 950 °C.

[0028] The at least one winding wire can be manufactured such that the cross-sectional profile of the at least one winding wire tapers conically inward in the radial direction.

[0029] The at least one winding wire can be wound around the support elements in such a way that at least for 50% of the surface of the wound wire filter the minimum distance between two winding wire windings is between 1 pm and 50 mm, preferably between 100 and 300 pm.

[0030] The support elements can preferably be arranged relative to one another and the winding wire can be wound around the support elements in such a way that the minimum distance between adjacent support elements is greater than the minimum distance between two winding wire windings.

[0031] In the following, an embodiment of the present invention is explained in more detail with reference to the drawings:

[0032] They show schematically:

[0033] Fig. 1 wound wire filter according to the invention with connecting elements,

[0034] Fig. 2 wound wire filter according to the invention, Fig. 3 section of Fig. 1 on one end of the wound wire filter,

[0035] Fig. 4 Cross-sectional view of a wound wire filter according to Fig. 1,

[0036] Fig. 5 a section of a longitudinal cross-section from Fig. 1,

[0037] Fig. 6 Cross sections of the support elements and winding wire,

[0038] Fig. 7 shows the surface analysis before an erosion test,

[0039] Fig. 8 shows the surface analysis after a 2-hour erosion test

[0040] Fig. 9 shows the surface analysis after a 48-hour erosion test

[0041] Fig. 10 shows the macro image after a 48-hour erosion test.

[0042] Fig. 1 shows a wound wire filter 1 with connecting elements 2. End rings 4 are provided at the ends of the wound wire filter 1. Wound wire filters can be used to filter oil, natural gas, or water reservoirs. For this purpose, they can be connected with connecting elements 2.

[0043] In an alternative embodiment not shown, the outer diameter of the wound wire filter can also be adapted to the outer diameter of the connecting element. The end ring can also be adapted to the outer diameter of the wound wire filter.

[0044] The wound wire filter 1 is shown in perspective in Fig. 2 without the connecting elements 2.

[0045] Fig. 2 shows that the wound wire filter 2 has support elements 6 that form a tubular support structure. Furthermore, at least one winding wire 8 is provided, which is wound around the support structure, wherein the at least one winding wire 8 and the support structure formed from support elements 6 are welded together.

[0046] The cross-sectional profiles of the support elements 6 each taper outward in the radial direction, and the support elements 6 are arranged relative to one another in such a way that they do not touch each other. The at least one support structure 6 and the at least one winding wire 8 are made of boron-coated steel.

[0047] Because the wound wire filter is made of boronized steel and the boron penetrates the material of the wound wire filter, the boron does not dissolve during use. The wound wire filter according to the invention is significantly more robust and exhibits fewer corrosion and erosion phenomena during use. Because the entire wound wire filter is boronized, the entire wound wire filter has a particularly high surface hardness. Boronization does not round off the edges of the winding wire, but leaves sharp edges. This is different from a coating, where the coating would round off the edges. Due to the sharp edges of the winding wire, there is less turbulence during use. The pressure loss is lower and the flow rate is improved.

[0048] Fig. 2 also clearly shows that, at least for 50% of the surface of the wound wire filter, the minimum distance between two winding wire windings can be between 1 μm and 50 mm. In the illustrated embodiment, the minimum distance between two winding wire windings is between 1 μm and 50 mm across the entire surface. Particularly preferably, for 50% of the surface of the wound wire filter, the minimum distance between two winding wire windings is between 100 μm and 300 μm.

[0049] In this way, the filtration of crude oil, natural gas and water can be carried out optimally.

[0050] Fig. 3 shows a section of one end of the wound wire filter 1 from Fig. 1. There, an end ring 4 is connected to the wound wire filter 1, preferably by welding. Furthermore, the end ring 4 is connected to further connecting elements 2. Furthermore, Fig. 3 also shows a section of a longitudinal cross-section of the wound wire filter 1. A longitudinal cross-section will also be described in more detail with reference to Fig. 5. The wound wire filter 1 has an outer diameter D and an inner diameter d. Furthermore, Fig. 3 shows the section through the wound wire filter 8. Furthermore, the cross-section runs between two adjacent support elements 6, so that Fig. 3 shows the side view of a support element 6.

[0051] The outer diameters of wound wire filters are usually given in inches. 1" corresponds to 2.54 cm. The diameters of the wound wire filter according to the invention can have an outer diameter preferably between 1" and 15", in particular between 1.5" and 10", particularly preferably between 1.9" and 7 5 / 8". In particular, the wound wire filter can have the following outer diameters: 1.9", 2 3 / 8", 2 7 / 8", 3 1 / 2", 4 1 / 2", 5 1 / 2".

[0052] 7.00" 7 5 / 8". However, the wound wire filter can also be any desired

[0053] outer diameter in between.

[0054] Fig. 4 is a cross-sectional view of a wound wire filter 1. The support elements 6, which form a tubular support structure, are shown in cross section. A view of the at least one winding wire 8 is also shown. In the radial outward direction R, the support elements 6 taper. Furthermore, it can be seen that the support elements are spaced apart from one another.

[0055] Due to the cross-sectional profiles according to the invention and the relative arrangement of the support elements and winding wire, the wound wire filter exhibits particularly good flow properties. Due to these good flow properties, erosion phenomena are reduced.

[0056] Fig. 5 shows a longitudinal cross-section of the wound wire filter 1. The at least one winding wire 8 is shown in section and a view of at least one support element 6 can be seen. For 50% of the surface of the wound wire filter 1, the minimum distance A between two winding wire windings 8a, 8b can be between 1 μm and 50 mm. The cross-sectional profile of the at least one winding wire 8 can also taper inwards in the radial direction B. Thus, the cross-sectional profiles of the support elements taper outwards in the radial direction R, whereas the cross-sectional profiles of the at least one wound wire filter taper inwards in the radial direction B.

[0057] Fig. 6 shows the cross-sectional profiles of the at least one winding wire 8 and the support elements 6. The width of the winding wire C is preferably smaller than the width F of the support elements. Furthermore, the height E of the at least one winding wire 8 is preferably smaller than the height H of the support elements 6. The cross-sectional profiles of the at least one winding wire and the at least one support element have a similar shape, namely a conical shape. As already described for the previous figures, the cross-sectional profiles are arranged differently, so that the cross-sectional profile of the support elements tapers conically outwards, whereas the cross-sectional profile of the at least one winding wire tapers conically inwards.

[0058] Fig. 7 shows the steps of a method for manufacturing a wound wire filter. In the first step, support elements are made of steel with a tapered cross-sectional profile.

[0059] Then, the support elements are arranged such that the arranged support elements form the shape of a tubular support structure and the cross-sectional profiles of the support elements are each tapered outwards in the radial direction, wherein the support elements are spaced apart from one another and do not touch one another.

[0060] These support elements are held in the arranged form by means of a holding device not shown.

[0061] In a further step (not shown), at least one steel winding wire is produced. This is wound around the support elements held by the holding device, and the winding wire is connected to the support elements by welding. The second image shows the support elements with the winding wire after welding.

[0062] The holding device is then removed, and the wound wire filter is boronized. The wound wire filter is preferably placed in a closed furnace 10, and the furnace 10 is heated in the presence of a boronizing agent. This is shown in the third image. The furnace temperature during heating is preferably between 750 and 950°C. The wound wire filter is thus preferably treated with the chemical element boron at temperatures of 750 to 950°C, so that boron penetrates the upper layers of the wound wire filter. These layers are preferably 100 to 250 μm thick. This creates a robust wound wire filter.

[0063] An erosion test was conducted on the wound wire filter according to the invention. The erosion test was carried out as described in the publication "Performance of Ceramic Sand Screen for High Rate Gas Application - Gas Sand Screen Erosion Testing" by Nickolas Manning; Paul Cadogan; Peter Barth; Ben Hoskin; Trent Read; David Manning; Richard Jackson; Bhargava Gundemoni; SPE Asia Pacific Oil and Gas Conference and Exhibition, Brisbane, Australia, October 2018. Paper Number: SPE-191942-MS.

[0064] The publication describes an erosion test and its application for evaluating erosion resistance. The erosion test was developed to simulate accelerated erosion conditions in a borehole. A gas-sand mixture is brought together at a high flow rate in an acceleration tube. The sand particles hit the borehole at high velocity (>80 m*s). -1) on the filter under investigation. In this study, the erosion test was carried out for 48 hours at maximum speed (>80 m*s -1) and a sand concentration of 750 ppmw. It should be noted that the velocities mentioned in this report are significantly higher than those that a conventional reservoir system would have to tolerate. During the erosion test, the test system is operated with compressed air. The main air flow is controlled by a volume flow controller. A secondary air flow is fed to the controller in the bypass and used for sand injection. The sand mass flow is adjusted using a sand dosing device with a worm gear and fed to the bypass at ambient pressure. After the main and secondary air flows have been combined, the air-sand mixture is passed through a horizontal pipe section in which the particles are accelerated and the specified impact velocity is reached. The erosion of test filters takes place in a sample chamber at the end of the pipe section, where the air-sand mixture impacts the filter surface perpendicularly.The design of the sample chamber ensures that the majority of particles are captured directly at the bottom of the chamber. Remaining particles in the air are removed from the exhaust air stream in a downstream cyclone.

[0065] Test conditions for the erosion tests: Gas flow rate 102 m 3 / h Sand injection rate 1.48 g / min Weight percent of 750 ppmw sand

[0066] Test temperature 298.15 K

[0067] Grain size (sand) 100 pm

[0068] Impact speed 80 m / s to 100 m / s

[0069] Impact angle 90°

[0070] For the test, the surface profiles of sections of the wound wire filter according to the invention were created using a Keyence VHX 2000 microscope before and after the erosion tests. Two erosion tests were conducted: one lasting 2 hours and one lasting 48 hours. All erosion tests were conducted under the above-mentioned conditions.

[0071] First, the initial surface profile analysis is performed before the first erosion test to compare the filter with subsequent measurements and detect potential damage. During this analysis, a strip along the filter surface is measured and a 3D model is created. The wound wire filter is then inserted into the test chamber. It is attached to the lid of the sample chamber with an additional flange, preventing the filter from moving and allowing the flow to reach the filter unhindered.

[0072] To commission the experimental device, the volume flow controller is first set to the desired value. Once this value is reached, the required mass flow of sand is injected into the air stream via an ejector using a sand dosing device. The filter is irradiated – as specified – over a period of either 2 hours or 48 hours.

[0073] Before performing an erosion test, the surface analysis shows a height difference of up to 100 pm between the bars of the wound wire filter (see Fig. 8).

[0074] Fig. 9 shows the surface profile of the same filter section after the 2-hour erosion test. No significant change in the surface is visible. The height difference between the individual ridges is even slightly smaller than before. Even after the 48-hour erosion test, no surface erosion can be measured along the profile line. The roughness of the individual ridges becomes even smaller. The height difference between the raised and non-raised surfaces is less than 50 μm. The three different lines in the figures show the results of three parallel comparison measurements. Note that the scale of the measurements varies in Figures 8-10.

[0075] Fig. 10 shows a macro image of the filter after the 48-hour erosion test. Slight surface wear is visible where the sand stream hits the filter. A comparison of the irradiated and unirradiated filter surfaces shows no significant height difference indicating erosion. For both the two-hour and 48-hour treatments, the erosion is so slight that it is masked by the initial unevenness of the individual ridges. Only a surface measurement on the 48-hour irradiated filter sample shows a slightly more uniform surface than the original sample, which could indicate marginal abrasion.

[0076] Overall, however, the wound wire filter has very good erosion resistance.

Claims

Claims 1. Winded wire filter (1) for filtering petroleum, natural gas or water, with - at least one tubular supporting structure formed from support elements (6), - at least one winding wire (8) which is wound around the supporting structure, wherein the at least one winding wire (8) and the supporting structure formed from support elements (6) are welded together, characterized in that the cross-sectional profiles of the support elements (6) are each tapered radially outwards and the support elements (6) are arranged to each other in such a way that they do not touch each other, wherein at least the supporting structure and the at least one winding wire (8) are made of boronized steel.

2. Winding wire filter (1) according to claim 1, characterized in that the cross-sectional profile of the at least one winding wire (8) is conically tapered inwards in the radial direction.

3. Winding wire filter (1) according to claim 1 or 2, characterized in that at least on 50% of the surface of the winding wire filter (1) the minimum distance (A) between two winding wire windings (8a, 8b) is between 1 pm and 50 mm.

4. Winding wire filter (1) according to one of claims 1 to 3, characterized in that the minimum distance between adjacent support elements (6) is greater than the minimum distance (A) between two winding wire windings (8a, 8b). A wire-wound filter (1) according to any one of claims 1 to 4, characterized in that an inner perforated tube is arranged within the support structure. A wire-wound filter (1) according to claim 5, characterized in that the perforated tube arranged within the support structure is treated with boron. A wire-wound filter (1) according to any one of claims 1 to 6, characterized in that the outer diameter of the wire-wound filter (1) is between 30 mm and 300 mm. A wire-wound filter (1) according to any one of claims 1 to 7, characterized in that the wire-wound filter (1) is connected, preferably welded, to a termination ring (4) at at least one of its two ends. A wire-wound filter (1) according to any one of claims 1 to 8, characterized in that the support structure and the at least one winding wire (8) are made of stainless steel. A method for manufacturing a wire-wound filter (1) by - Providing steel support elements (8) which each have cross-sectional profiles which are each tapered, - Arranging the support elements (8), wherein the support elements (8) are arranged such that the arranged support elements (8) form the shape of a tubular support structure and the cross-sectional profiles of the support elements (8) are each tapered radially outwards, wherein the support elements (8) are abutted from each other and do not touch each other, - Holding the support elements (8) in the arranged shape by means of a holding device, - Providing at least one steel winding wire (6), - Winding the winding wire (6) around the arranged support elements (8) held by means of the holding device, - Connecting the winding wire (6) to the support elements (8) by means of a welding process, - Removal of the holding device, - Boring of the winding wire filter (1). Method according to claim 10, characterized in that the boroning comprises the following steps: - Inserting the support elements (8) and the winding wire (6) connected to the support elements (8) into a closed oven (10), - Heating in the presence of a boronizing agent. Method according to claim 11, characterized in that the heating is carried out at 750 to 950 °C. Method according to any one of claims 10 to 12, characterized in that the at least one winding wire (6) is produced such that the cross-sectional profile of the at least one winding wire (6) is radially conical inwards. Method according to claim 13, characterized in that the at least one winding wire (6) is wound around the support elements (8) such that, at least over 50% of the surface of the winding wire filter, the minimum distance between two winding wire coils is between 1 pm and 50 mm. Method according to any one of claims 10 to 14, characterized in that the support elements are arranged relative to each other. and the winding wire is wound around the support elements in such a way that the minimum distance between adjacent support elements is greater than the minimum distance between two winding wire coils.

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