Inverted weight increasing structure suitable for oil and gas well variable-diameter pipe column test

Abstract

The utility model discloses an upside-down hanging weighting structure suitable for an oil and gas well variable-diameter tubular column test, which comprises a weighting body with a length, the two ends of the weighting body along the length direction are respectively an upper end and a lower end, the weighting body is provided with a hollow channel for a cable connected with a test instrument to pass through, and a clamping end is formed at the lower end of the weighting body. When the weighting device is used, the clamping end is clamped at the reducing position of a large-diameter pipe column and a small-diameter pipe column, the weighting body is located on the upstream of a testing instrument so as to go down a well synchronously, the testing instrument enters the small-diameter pipe column when the weighting device reaches the reducing position, and the clamping end of the weighting body is clamped at the reducing position. The problem that an oil and gas well test cannot be completed due to the fact that the weight of the weighting rod of the annular logging instrument is too light is solved, and later logging site practical application is facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of well logging testing operations for high-pressure, deep (ultra-deep) oil and gas wells with small diameter variations in oil pipes in the petroleum industry, and in particular to an inverted weighting structure suitable for testing variable diameter pipe strings in oil and gas wells. Background Art

[0002] When recording dynamic data from high-pressure, deep (or ultra-deep) oil and gas wells, the logging instrument must be lowered into the production zone. Because the instrument itself is not sufficiently heavy, a weighted rod is often added to the instrument to provide additional counterweight. This weighted rod is installed below the instrument and lowered simultaneously to ensure the logging instrument reaches the target testing depth. Due to the presence of completion equipment such as sleeves and ball seats within the tubing string of oil and gas wells, there are variable diameter tubing strings, where the diameter of the tubing string changes from large to small, down to a diameter of ≤φ35mm. Therefore, existing conventional large-diameter weighted rods (φ38, φ43mm) cannot pass through them normally.

[0003] Therefore, it is necessary to equip a smaller-sized test instrument, and accordingly, a smaller-diameter weight rod is needed to meet the test requirements. Currently, only the annulus test instrument (φ26mm) meets the conditions. If a φ26mm weight rod is used, the instrument weight can be increased in two aspects: 1. Increasing the length of the weight rod, but the increase in length will make the test instrument string too long, which will easily cause problems such as jamming, obstruction, and deformation; 2. Changing the material of the weight rod. Tungsten steel is currently commonly used, which is the heaviest and most suitable material, but due to the diameter of φ26mm, the weighting effect is not ideal. Therefore, these two improvement methods still cannot meet the test requirements in high-pressure oil and gas well testing. Therefore, it is necessary to develop a weight rod that can meet the requirements of heavy weight and ensure that the test instrument can pass through the variable diameter smoothly to improve the test success rate. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide an inverted weighting structure suitable for testing variable diameter pipe strings in oil and gas wells, which can not only meet the requirements of weight bearing capacity but also ensure that the test instrument can pass through the variable diameter smoothly. The specific technical solution is as follows:

[0005] An inverted weight structure suitable for testing a variable diameter tubing string in an oil and gas well. The variable diameter tubing string includes a large diameter tubing string and a small diameter tubing string arranged and connected in an upstream and downstream direction within the oil and gas well. The inverted weight structure includes a weight body having a length. The weight body has an upper end and a lower end along its length, respectively. The weight body defines a hollow passage extending through the upper and lower ends and along its length for passage of a cable connected to a testing instrument. A clamping end is formed at the lower end of the weight body. When in use, the clamping end is clamped to the diameter change point between the large diameter tubing string and the small diameter tubing string. A direction perpendicular to the length direction is a radial direction. The entire radial dimension of the weight body upstream of the clamping end is smaller than the inner diameter of the large diameter tubing string. The diameter of the testing instrument is smaller than the inner diameter of the small diameter tubing string. When in use, the weight body is located upstream of the testing instrument to be lowered into the well synchronously. When the testing instrument reaches the diameter change point, the clamping end of the weight body is clamped to the diameter change point.

[0006] Preferably, the inner diameter of the hollow channel matches the diameter of the cable, and a drainage channel is provided at the position where the clamping end is clamped with the diameter reducing portion, and the drainage channel connects the internal space of the small-diameter pipe column with the internal space of the large-diameter pipe column.

[0007] Preferably, a conical section is formed at the lower end of the weighted body, the upstream section of the conical section is located in the internal space of the large-diameter pipe column, and the downstream section extends into the internal space of the small-diameter pipe column. A plurality of drainage grooves extending in the upstream and downstream directions are provided on the outer peripheral side wall of the conical section to form the drainage channel, and the intersection of the upstream section and the downstream section of the conical section abuts against the opening of the small-diameter pipe column to form the clamping end.

[0008] Preferably, the number of the drainage grooves is 4, and the 4 drainage grooves are evenly spaced along the circumferential direction of the outer peripheral side wall.

[0009] Preferably, the weighted body is a rod.

[0010] Preferably, the diameter of the testing instrument is 26 mm, and the diameter of the rod is 38 mm.

[0011] Preferably, the diameter of the testing instrument is 26 mm, and the diameter of the rod is 43 mm.

[0012] Preferably, the diameter of the rod body matches the inner diameter of the large diameter pipe column.

[0013] The provided inverted weighted structure suitable for oil and gas well variable diameter tubing string testing has the following technical effects:

[0014] The conventional solid weighted rod is processed to be hollow inside (to ensure a certain counterweight). When in use, the cable is passed through the rod body and a rope cap is made at the bottom to connect to the testing instrument. When the rod body smoothly brings the logging tool to the diameter change in the oil pipe, the cable brings the testing instrument below through the diameter change smoothly, and the rod body is clamped and placed above the diameter change (the bottom is conical and 4 drainage grooves are set to prevent the rod body from sitting at the diameter change to block the oil and gas flow channel). After the logging work is completed, the cable is lifted up to take out the rod body and the logging instrument. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a half-section schematic diagram of the inverted weighted structure provided by the present invention, which is suitable for testing variable-diameter tubing strings in oil and gas wells, with the section line being along its axial direction.

[0016] Figure 1 The accompanying drawings are numerals as follows:

[0017] 1 hollow channel, 2 conical section, 3 drainage trough, 4 rod body, 5 rope cap head, 6 weighted rod, 7 guide head. DETAILED DESCRIPTION

[0018] The present invention will be described in further detail below.

[0019] The present invention will be described in more detail below with reference to the accompanying drawings, which illustrate preferred embodiments of the present invention. It should be understood that those skilled in the art may modify the present invention described herein while still achieving the beneficial effects of the present invention. Therefore, the following description should be understood as a general guide for those skilled in the art and not as a limitation of the present invention.

[0020] For the sake of clarity, not all features of the actual embodiments are described. In the following description, well-known functions and structures are not described in detail because they would obscure the present invention with unnecessary detail. It should be understood that in the development of any actual embodiment, numerous implementation details must be made to achieve the developer's specific goals.

[0021] In order to make the purpose and features of the present invention more obvious and easy to understand, the following is a further description of the specific embodiments of the present invention in conjunction with the accompanying drawings. It should be noted that the drawings are all in a very simplified form and use non-precise ratios, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0022] Combine Figure 1The utility model provides an inverted weighting structure suitable for testing variable diameter pipe strings in oil and gas wells, wherein the variable diameter pipe string includes a large diameter pipe string and a small diameter pipe string arranged and connected in the upstream and downstream directions in the oil and gas well, and the inverted weighting structure includes a weighting body having a length, and the two ends of the weighting body along the length direction are respectively an upper end and a lower end, and the weighting body is provided with a hollow channel 1 that passes through the upper and lower ends and extends along the length direction for the cable connected to the test instrument to pass through, and a clamping joint is formed at the lower end of the weighting body End, when in use, the clamping end is clamped at the diameter change point between the large-diameter pipe string and the small-diameter pipe string, the direction perpendicular to the length direction is the radial direction, the overall radial size of the weighted body located upstream of its clamping end is smaller than the inner diameter of the large-diameter pipe string, the diameter of the testing instrument is smaller than the inner diameter of the small-diameter pipe string, and the weighted body is located upstream of the testing instrument to be lowered into the well synchronously when in use, and when reaching the diameter change point, the testing instrument enters the small-diameter pipe string, and the clamping end of the weighted body is clamped at the diameter change point.

[0023] In one specific embodiment, the inner diameter of the hollow channel 1 matches the diameter of the cable, and a drainage channel is provided at the location where the clamping end and the diameter reducer engage, connecting the interior space of the small-diameter pipe string with the interior space of the large-diameter pipe string. This matching means that the cable diameter is very close to the inner diameter of the hollow channel 1, which prevents the inner diameter of the hollow channel 1 from being too large and thus unable to ensure a certain counterweight.

[0024] In a specific embodiment, Figure 1 As shown, a conical section 2 is formed at the lower end of the weighted body, the upstream section of the conical section 2 is located in the internal space of the large-diameter pipe column, and the downstream section extends into the internal space of the small-diameter pipe column. A plurality of drainage grooves 3 extending in the upstream and downstream directions are provided on the outer peripheral side wall of the conical section 2 to form the drainage channel, and the intersection of the upstream section and the downstream section of the conical section 2 abuts against the opening of the small-diameter pipe column to form the clamping end.

[0025] There are four drainage grooves 3 , which are evenly spaced along the circumferential direction of the outer side wall.

[0026] In one embodiment, the weighted body is a rod body 4. The rod body 4 includes a rope cap 5, a weighted rod 6, and a guide head 7, which are sequentially connected by screws. The rope cap 5, weighted rod 6, and guide head 7 are all hollow and sequentially connected to form the hollow channel 1. The conical section 2 is formed at the downstream end of the guide head 7. The outer diameters of the rope cap 5, weighted rod 6, and guide head 7 are substantially the same, which is the diameter of the rod body 4.

[0027] Among them, Figure 1As shown, the drainage groove 3 is provided through the conical section 2 and extends toward the upstream direction, and may extend to the outer side wall of the guide head 7 .

[0028] In a specific embodiment, the diameter of the testing instrument is 26 mm, and the diameter of the rod body 4 is 38 mm.

[0029] In a specific embodiment, the diameter of the testing instrument is 26 mm, and the diameter of the rod body 4 is 43 mm.

[0030] The diameter of the rod body 4 matches the inner diameter of the large-diameter pipe string. This matching means that the diameter of the rod body 4 is very close to the inner diameter of the large-diameter pipe string, which can ensure a certain counterweight.

[0031] This utility model is suitable for testing in high-pressure, deep (or ultra-deep) oil and gas wells where the tubing has small diameter changes. Due to the high wellhead pressure, the φ26mm weighted rod is too light to smoothly carry the logging tool to the bottom test section. By adding counterweight to the annular logging tool string, the inverted weighted rod ensures that the tool string can smoothly pass through the oil well diameter change and successfully complete the testing task, thereby improving the logging success rate and having a wide range of engineering applications.

[0032] The above shows and describes the basic principles, main features and advantages of the present invention. Therefore, the above description is only an embodiment of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiment. The above embodiment and description only describe the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention also includes various equivalent changes and improvements, which will fall within the scope of the present invention. The scope of protection claimed in this utility model is defined by the appended claims and their equivalents.

Claims

1. An inverted weighting structure suitable for testing variable diameter tubing strings in oil and gas wells, characterized in that: The reducer string includes a large-diameter string and a small-diameter string arranged and connected in the upstream and downstream directions in the oil and gas well, the inverted weight structure includes a weight body with a length, the two ends of the weight body along its length direction are respectively an upper end and a lower end, the weight body is provided with a hollow channel running through its upper and lower ends and extending along the length direction for the cable connected to the test instrument to pass through, a clamping end is formed at the lower end of the weight body, and when in use, the clamping end is clamped at the diameter reduction point of the large-diameter string and the small-diameter string, a direction perpendicular to the length direction is the radial direction, the overall radial dimension of the weight body located upstream of its clamping end is smaller than the inner diameter of the large-diameter string, the diameter of the test instrument is smaller than the inner diameter of the small-diameter string, and when in use, the weight body is located upstream of the test instrument to be synchronously lowered into the well, and when reaching the diameter reduction point, the test instrument enters the small-diameter string and the clamping end of the weight body is clamped at the diameter reduction point.

2. The inverted weighting structure suitable for testing variable diameter tubing strings in oil and gas wells according to claim 1 is characterized in that: The inner diameter of the hollow channel matches the diameter of the cable, and a drainage channel is provided at the position where the clamping end is clamped with the diameter reducing portion, and the drainage channel connects the internal space of the small-diameter pipe column with the internal space of the large-diameter pipe column.

3. The inverted weighted structure suitable for testing variable diameter tubing strings in oil and gas wells according to claim 2 is characterized in that: A conical section is formed at the lower end of the weighted body, the upstream section of the conical section is located in the internal space of the large-diameter pipe column, and the downstream section extends into the internal space of the small-diameter pipe column. A plurality of drainage grooves extending in the upstream and downstream directions are provided on the outer peripheral side wall of the conical section to form the drainage channel. The intersection of the upstream section and the downstream section of the conical section abuts against the opening of the small-diameter pipe column to form the clamping end.

4. The inverted weighted structure suitable for testing a variable diameter tubing string in an oil and gas well according to claim 3 is characterized in that: The number of the drainage grooves is 4, and the 4 drainage grooves are evenly spaced along the circumferential direction of the outer peripheral side wall.

5. The inverted weighting structure suitable for testing variable diameter tubing strings in oil and gas wells according to claim 4 is characterized in that: The weighted body is a rod body.

6. The inverted weighted structure suitable for testing variable diameter tubing strings in oil and gas wells according to claim 5 is characterized in that: The diameter of the testing instrument is 26 mm, and the diameter of the rod is 38 mm.

7. The inverted weighted structure for testing a variable diameter tubing string in an oil and gas well according to claim 5 is characterized in that: The diameter of the testing instrument is 26 mm, and the diameter of the rod is 43 mm.

8. The inverted weighted structure suitable for testing variable diameter tubing strings in oil and gas wells according to claim 5 is characterized in that: The diameter of the rod body matches the inner diameter of the large diameter pipe string.

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