Perforating gun rotation angle detection method for oil and gas well

Abstract

The invention relates to a method for detecting the rotation angle of a perforating gun for an oil and gas well, which comprises the following steps of: mounting a gravity type three-axis tilt angle sensor on the perforating gun, enabling one of the X axis, the Y axis and the Z axis of the three-axis tilt angle sensor to coincide with the center line of the perforating gun, and recording the plane of the other two axes as a projection plane; the included angles between three axes and the gravity G or the horizontal plane when the perforating gun is located at the first position and the second position are measured through the three-axis tilt angle sensor, the change of the coordinate axis with the gravity G as the reference system is converted into the direction change of the gravity G with the coordinate system composed of the X axis, the Y axis and the Z axis as the reference system, and after the conversion, the position of the perforating gun is determined. Calculating the change angle of the direction of the gravity G on the projection surface, namely the rotation angle of the perforating gun; compared with the prior art, the angle deviation between the actual perforation direction of the perforating gun and the calibrated perforation direction at the wellhead can be effectively detected, then the angle of the perforating gun is adjusted and corrected, and perforation deviation and faults are avoided.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction technology, and specifically to a method for detecting the rotation angle of a perforating gun used in oil and gas wells. Background Technology

[0002] A perforating gun is a specialized tool used in the perforation stage of oil and gas well completion operations. It mainly consists of a gun body, gun head, gun tail, and sealing components. It fires a perforating projectile to penetrate the casing and cement sheath, creating a channel in the rock formation and establishing a connection between the formation and the wellbore, allowing oil and gas to flow into the wellbore. Currently, due to issues such as geomagnetism, long working times, and the tilting of perforating guns used in oil and gas wells, during directional perforation operations, after the perforating gun reaches the perforation position (the second position) after pumping, it is impossible to detect the angular deviation between the actual perforation direction and the perforation direction marked at the wellhead (the first position). This deviation (i.e., the rotation angle of the perforating gun around its centerline from the first position to the second position) can easily lead to perforation deviation and malfunctions. Summary of the Invention

[0003] The purpose of this invention is to address the problem in the prior art that, after pumping is completed, the perforating gun for oil and gas wells cannot detect the angular deviation between the actual perforation direction and the perforation direction calibrated at the wellhead, which easily leads to perforation deviation and malfunctions. This invention provides a method for detecting the rotation angle of a perforating gun for oil and gas wells.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] A method for detecting the rotation angle of a perforating gun used in oil and gas wells includes the following steps:

[0006] a. Install a gravity-type three-axis tilt sensor on the perforating gun, so that one of the X, Y, and Z axes of the three-axis tilt sensor coincides with the center line of the perforating gun, and denote the plane containing the other two axes as the projection plane.

[0007] b. When the perforating gun is in the first position, the triaxial tilt sensor outputs the angles α, β, and γ between its X, Y, and Z axes and gravity G; when the perforating gun is in the second position, the triaxial tilt sensor outputs the angles α′, β′, and γ′ between its X, Y, and Z axes and gravity G; or, when the perforating gun is in the first position, the triaxial tilt sensor outputs the angles δ, ε between its X, Y, and Z axes and the horizontal plane. When the perforating gun is in the second position, the triaxial tilt sensor outputs the angles δ′, ε′ between its X, Y, and Z axes and the horizontal plane. In both the first and second positions, the centerline of the perforating gun is not perpendicular to the horizontal plane.

[0008] c. Using the coordinate system composed of the X, Y, and Z axes as the reference system, when the perforating gun is in the first position, the projection direction of gravity G on the projection plane is denoted as the first direction, and when the perforating gun is in the second position, the projection direction of gravity G on the projection plane is denoted as the second direction; calculate the angle between the first direction and the second direction, which is the rotation angle θ of the perforating gun.

[0009] The present invention, employing the aforementioned technical solution, involves step a, namely, installing a gravity-type three-axis tilt sensor on the perforating gun, such that one of the X, Y, and Z axes of the three-axis tilt sensor coincides with the centerline of the perforating gun, and the plane containing the other two axes is designated as the projection plane; then the rotation angle of the perforating gun is the rotation angle of any one of the other two axes on the projection plane; when the perforating gun moves from the first position to the second position, if gravity G is used as the reference frame, the directions of the coordinate axes X, Y, and Z will change, but the relative positions of the three axes remain unchanged, still perpendicular to each other. In this invention, the changes in the coordinate axes with gravity G as the reference frame are converted into X, Y, and Z... The coordinate system composed of axes is the reference system. The direction of gravity G changes. After this transformation, the rotation angle of the perforating gun can be calculated according to the calculation method in step c, combined with the angle data in step b. Compared with the existing technology, which cannot detect the angular deviation between the actual perforation direction of the perforating gun and the perforation direction marked at the wellhead after pumping and reaching the perforation position, leading to the problem of easy perforation deviation and failure, this invention can effectively detect the angular deviation between the actual perforation direction of the perforating gun and the perforation direction marked at the wellhead, and then adjust and correct the perforating gun angle to avoid perforation deviation and prevent failure.

[0010] Furthermore, the triaxial tilt sensor outputs α, β, γ, α′, β′, γ′; when the X-axis coincides with the center line of the perforating gun, When the Y-axis coincides with the center line of the perforating gun When the Z-axis coincides with the center line of the perforating gun When the triaxial tilt sensor outputs the values ​​of α, β, γ, α′, β′, and γ′, the rotation angle θ can be calculated according to the spatial vector mathematical formula in step c.

[0011] Furthermore, the triaxial tilt sensor outputs δ, ε, δ′、ε′、 When the X-axis coincides with the center line of the perforating gun When the Y-axis coincides with the center line of the perforating gun When the Z-axis coincides with the center line of the perforating gun When the triaxial tilt sensor outputs δ, ε, δ′、ε′、 Since the angle between gravity G and the horizontal plane is 90°, α = δ + 90°, β = ε + 90°. α′=δ′+90°, β′=ε′+90°, Substituting the previously mentioned formula for the rotation angle θ expressed by α, β, γ, α′, β′, γ′, we can obtain the formula for the rotation angle θ expressed by δ, ε, α′, γ′, α′, β ... δ′、ε′、 The formula for expressing the rotation angle θ.

[0012] Furthermore, the triaxial tilt sensor is an integrated single triaxial tilt sensor, or it is composed of multiple biaxial or single-axis tilt sensors.

[0013] Compared with the prior art, the beneficial effects of the present invention are: it can effectively detect the angular deviation between the actual perforation direction of the perforating gun and the perforation direction calibrated at the wellhead, and then adjust and correct the angle of the perforating gun to avoid perforation deviation and prevent malfunctions. Attached Figure Description

[0014] Figure 1 A schematic diagram of a perforating gun equipped with a triaxial tilt sensor;

[0015] Figure 2 for Figure 1 A simplified model diagram;

[0016] Figure 3 This is a schematic diagram showing the changes in the coordinate axis directions with gravity G as the reference frame;

[0017] Figure 4 This is a schematic diagram showing the change in the direction of gravity G with the coordinate system as the reference frame;

[0018] Figure 5 This is a schematic diagram showing the change in the projection direction of gravity G on the projection plane.

[0019] Figure 6 In order to be in Figure 5 A schematic diagram of the projection onto the projection plane after taking a vector on the gravity G.

[0020] Markings in the diagram: 1-Perforating gun, 2-Triaxial tilt sensor, 3-Perforating gun centerline. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings.

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0023] This invention provides a method for detecting the rotation angle of a perforating gun used in oil and gas wells, comprising the following steps:

[0024] a. Install a gravity-type three-axis tilt sensor 2 on the perforating gun 1, so that one of the X, Y, and Z axes of the three-axis tilt sensor 2 coincides with the center line 3 of the perforating gun, and denote the plane containing the other two axes as the projection plane.

[0025] b. When the perforating gun 1 is in the first position, the triaxial tilt sensor 2 outputs the angles α, β, and γ between its X, Y, and Z axes and gravity G; when the perforating gun 1 is in the second position, the triaxial tilt sensor 2 outputs the angles α′, β′, and γ′ between its X, Y, and Z axes and gravity G; or, when the perforating gun 1 is in the first position, the triaxial tilt sensor 2 outputs the angles δ, ε, and γ between its X, Y, and Z axes and the horizontal plane. When the perforating gun 1 is in the second position, the triaxial tilt sensor 2 outputs the angles δ′, ε′ between its X, Y, and Z axes and the horizontal plane. In this case, when the perforating gun 1 is in the first position and the second position, the center line 3 of the perforating gun is not perpendicular to the horizontal plane; if the center line 3 of the perforating gun is perpendicular to the horizontal plane during the process of the perforating gun 1 moving from the first position to the second position, it will not affect the realization of this detection method.

[0026] c. Using the coordinate system formed by the X, Y, and Z axes as the reference system, when the perforating gun 1 is in the first position, the projection direction of gravity G on the projection plane is denoted as the first direction; when the perforating gun 1 is in the second position, the projection direction of gravity G on the projection plane is denoted as the second direction. Calculate the angle between the first and second directions, which is the rotation angle θ of the perforating gun 1. Note that the rotation of the perforating gun 1 in this paper refers to the rotation of the perforating gun 1 around the center line 3 of the perforating gun, excluding other motions.

[0027] If the triaxial tilt sensor 2 outputs α, β, γ, α′, β′, γ′; when the X-axis coincides with the center line 3 of the perforating gun, When the Y-axis coincides with the center line 3 of the perforation gun When the Z-axis coincides with the center line 3 of the perforating gun

[0028] The following is a detailed explanation of the case where the Y-axis coincides with the center line 3 of the perforation gun:

[0029] like Figure 1 As shown, the triaxial tilt sensor 2 is mounted on the perforating gun 1, with its Y-axis coinciding with the centerline 3 of the perforating gun. Clearly, the projection plane is the XZ plane. For ease of description and understanding, the images in subsequent calculations will no longer show the perforating gun 1 and the triaxial tilt sensor 2, but only the coordinate axes. The simplified results are as follows: Figure 2 As shown;

[0030] When the perforating gun 1 moves from the first position to the second position, this process can be regarded as a rotational transformation of the coordinate axes X, Y, and Z with gravity G as the reference frame. This transformation process is as follows: Figure 3 As shown, since the Y-axis coincides with the center line 3 of the perforating gun, and since the X-axis, Y-axis and Z-axis are perpendicular to each other, the rotation angle of the perforating gun 1 is the rotation angle of the X-axis or Z-axis in the XZ plane.

[0031] Since the coordinate axes X, Y, and Z are perpendicular to each other, their relative positions do not change. Therefore, for ease of calculation, this paper transforms the coordinate axis transformation with gravity G as the reference frame into the change in the direction of gravity G with the coordinate system composed of the X, Y, and Z axes as the reference frame. Figure 4 As shown; as mentioned earlier, the rotation angle of the perforating gun 1 is the rotation angle of the X-axis or Z-axis on the XZ plane. Therefore, the rotation angle of the perforating gun 1 can be converted into the change of the projection of gravity G on the XZ plane, as follows: Figure 5 As shown in the figure, angle θ is the rotation angle of the perforating gun 1;

[0032] To calculate angle θ, such as Figure 6 As shown, a vector of length 1 is taken on the gravity G. Take a vector of length 1 along the gravitational force G'. and The vector coordinates projected onto the XZ plane are vectors. sum vector Where the angle θ is and The included angle;

[0033] As can be seen from the above, and The length is 1. The angles between the x, y, and z axes are α, β, and γ, respectively. The angles between the x, y, and z axes are α′, β′, and γ′, respectively, therefore we can obtain... Coordinates and magnitude:

[0034]

[0035] Therefore, according to the formula for the angle between vectors, the formula for calculating angle θ is as follows:

[0036]

[0037] Similarly, if the X-axis coincides with the center line 3 of the perforation gun, then: Similarly, if the Z-axis coincides with the center line 3 of the perforating gun, then:

[0038] If the triaxial tilt sensor 2 outputs δ, ε, δ′、ε′、 When the X-axis coincides with the center line 3 of the perforating gun When the Y-axis coincides with the center line 3 of the perforation gun When the Z-axis coincides with the center line 3 of the perforating gun

[0039] The following is a detailed explanation of the case where the Y-axis coincides with the center line 3 of the perforation gun:

[0040] Since the angle between gravity G and the horizontal plane is 90°, we have the following formula:

[0041] α=δ+90°, β=ε+90°, α′=δ′+90°, β′=ε′+90°,

[0042] Substitute the above formula into get:

[0043] Based on the relationships between trigonometric functions, it can be simplified to:

[0044]

[0045] Similarly, if the X-axis coincides with the center line 3 of the perforation gun, then: Similarly, if the Z-axis coincides with the center line 3 of the perforating gun, then:

[0046] The triaxial tilt sensor 2 can be an integrated single triaxial tilt sensor, or a combination of multiple biaxial or single-axis tilt sensors. For example, three single-axis tilt sensors can be orthogonally fixed to the perforating gun 1 along the X, Y, and Z axes respectively. Each tilt sensor measures the tilt in one direction independently, and the three single-axis data are finally combined into a triaxial result. Alternatively, two biaxial tilt sensors can be combined, with the first measuring the X and Y axes and the second measuring the X and Z axes. Through data redundancy and calculation, the angles of the three axes can also be derived. Among these, the single-axis tilt sensor, the biaxial tilt sensor, and the integrated single triaxial tilt sensor are all existing technologies that can output the angle between the axis and gravity or the horizontal plane. Their structures will not be described in detail here.

[0047] The present invention, employing the aforementioned technical solution, involves step a, namely, installing a gravity-type triaxial tilt sensor 2 on the perforating gun 1, such that one of the X, Y, and Z axes of the triaxial tilt sensor 2 coincides with the center line 3 of the perforating gun, and the plane containing the other two axes is designated as the projection plane; then the rotation angle of the perforating gun 1 is the rotation angle of any one of the other two axes on the projection plane; when the perforating gun 1 moves from the first position to the second position, if gravity G is used as the reference frame, the directions of the coordinate axes X, Y, and Z will change, but the relative positions of the three axes remain unchanged, still perpendicular to each other. In this invention, the changes in the coordinate axes with gravity G as the reference frame are converted into changes in the X, Y, and Z axes. The direction of gravity G changes in the coordinate system formed by the Y and Z axes as the reference frame. After this transformation, the rotation angle of the perforating gun 1 can be calculated according to the calculation method in step c, combined with the angle data in step b. Compared with the existing technology where the perforating gun for oil and gas wells cannot detect the angular deviation between the actual perforation direction of the perforating gun and the perforation direction marked at the wellhead after pumping, which easily leads to perforation deviation and malfunction, this invention can effectively detect the angular deviation between the actual perforation direction of the perforating gun and the perforation direction marked at the wellhead, and then adjust and correct the perforating gun angle to avoid perforation deviation and prevent malfunction.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for detecting the rotation angle of a perforating gun used in oil and gas wells, characterized in that, Includes the following steps: a. Install a gravity-type three-axis tilt sensor (2) on the perforating gun (1) so that one of the X, Y, and Z axes of the three-axis tilt sensor (2) coincides with the center line (3) of the perforating gun. The plane containing the other two axes is called the projection plane. b. When the perforating gun (1) is in the first position, the triaxial tilt sensor (2) outputs the angles α, β, and γ between its X, Y, and Z axes and gravity G; when the perforating gun (1) is in the second position, the triaxial tilt sensor (2) outputs the angles α′, β′, and γ′ between its X, Y, and Z axes and gravity G; or, when the perforating gun (1) is in the first position, the triaxial tilt sensor (2) outputs the angles δ, ε, and γ′ between its X, Y, and Z axes and the horizontal plane. When the perforating gun (1) is in the second position, the triaxial tilt sensor (2) outputs the angles δ′, ε′, and φ′ between its X, Y, and Z axes and the horizontal plane. In the first and second positions, the center line (3) of the perforating gun (1) is not perpendicular to the horizontal plane. c. Using the coordinate system composed of the X, Y, and Z axes as the reference system, when the perforating gun (1) is in the first position, the projection direction of gravity G on the projection surface is recorded as the first direction. When the perforating gun (1) is in the second position, the projection direction of gravity G on the projection surface is recorded as the second direction. Calculate the angle between the first direction and the second direction, which is the rotation angle θ of the perforating gun (1).

2. The method for detecting the rotation angle of a perforating gun for oil and gas wells according to claim 1, characterized in that, The triaxial tilt sensor (2) outputs α, β, γ, α′, β′, γ′; when the X-axis coincides with the center line (3) of the perforating gun, When the Y-axis coincides with the center line (3) of the perforating gun, When the Z-axis coincides with the center line (3) of the perforating gun, 3. The method for detecting the rotation angle of a perforating gun for oil and gas wells according to claim 1, characterized in that, The triaxial tilt sensor (2) outputs δ, ε, δ′、ε′、 When the X-axis coincides with the center line (3) of the perforating gun, When the Y-axis coincides with the center line (3) of the perforating gun, When the Z-axis coincides with the center line (3) of the perforating gun, 4. The method for detecting the rotation angle of a perforating gun for oil and gas wells according to claim 1, characterized in that, The triaxial tilt sensor (2) is an integrated single triaxial tilt sensor, or it is composed of multiple biaxial or single-axis tilt sensors.

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