A method for generating annulus geometry model of oil and gas wells

Abstract

A method for generating an annulus geometry model of an oil and gas well, comprising: determining the continuous functions of each preset engineering parameter in a preset engineering parameter set as the well depth changes according to the measured data obtained during the cementing process, and obtaining a first function set; determining the axis coordinate function of the annulus geometry according to the first function set, and obtaining a second function set; determining the inner diameter coordinate function and the outer diameter coordinate function of the annulus geometry in a three-dimensional coordinate system according to the first function set, and obtaining a third function set; using the second function set to adjust the third function set, and generating an annulus geometry model of the oil and gas well. This method can accurately describe the geometry of the annulus of an oil and gas well by constructing an annulus geometry, which is helpful for studying the progress of cementing and completion in oil and gas well engineering.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas exploration and development, and in particular to a method for generating an oil and gas well annulus geometric model. Background Art

[0002] Cementing is the last step in the drilling process of oil and gas wells and is the key process connecting drilling and oil production. Improving displacement efficiency is the basic prerequisite for ensuring cementing quality. Among the methods for studying displacement efficiency, cementing displacement numerical simulation has the advantages of not considering experimental conditions and low cost.

[0003] With the development of hardware and software such as computer memory, the numerical simulation capabilities of computers have been enhanced, and numerical simulation has gradually become an important means to study the cementing displacement process. In the numerical simulation of cementing displacement, the flow law of the fluid in the annulus of actual size requires a huge number of grids to describe physical parameters such as wellbore trajectory, centering, and wellbore diameter. Based on this, a physical model can be established to perform numerical simulation of the slurry displacement process in cementing. In this process, the quality of the grid plays a decisive role in the accuracy and efficiency of the simulation. Therefore, based on the actual flow law of the slurry in cementing displacement, establishing a grid model that meets accuracy and efficiency is an important guarantee for simulating the slurry flow process in the entire well section. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a method for generating an annulus geometry model of an oil and gas well, the method comprising:

[0005] Step 1: Determine the continuous function of each preset engineering parameter in the preset engineering parameter set as the function of the well depth according to the measured data obtained during the cementing process, and obtain a first function set;

[0006] Step 2: According to the first function set, determine the axis coordinate function of the annular geometric body in a Cartesian coordinate system to obtain a second function set;

[0007] Step 3: According to the first function set, determine the inner diameter coordinate function and the outer diameter coordinate function of the annulus geometric body in the Cartesian coordinate system under the three-dimensional coordinate system respectively to obtain a third function set;

[0008] Step 4: Use the second function set to adjust the third function set to generate an annulus geometry model of the oil and gas well, wherein in the process of generating the annulus geometry model of the oil and gas well, the second function set is used to adjust the inner diameter coordinate function and the outer diameter coordinate function of the annulus geometry under different well depth conditions, respectively, to perform coordinate transformation, thereby obtaining the annulus geometry model.

[0009] According to one embodiment of the present invention, in step 1,

[0010] determining the horizontal displacement of the wellbore trajectory according to the measured data;

[0011] According to the measured data and the horizontal displacement of the wellbore, the continuous function of each preset engineering parameter changing with the well depth is determined by using the difference method.

[0012] According to one embodiment of the present invention, the horizontal displacement of the wellbore trajectory is determined according to the following expression:

[0013] hd(i)=hd(i-1)+[vd(i)-vd(i-1)]×tan[θ(i)+θ(i-1) / 2]

[0014] Among them, hd represents the horizontal displacement of the wellbore trajectory, vd represents the vertical depth, θ represents the well inclination angle, and i and i-1 both represent the measurement point numbers.

[0015] According to an embodiment of the present invention, the preset engineering parameter set includes at least one of the following items:

[0016] Vertical depth, centering, well inclination, horizontal displacement, and well diameter.

[0017] According to an embodiment of the present invention, in the step 2, the second function set is determined according to the following expression:

[0018] x1(r,α,d)=hd(d)

[0019] z1(r,α,d)=vd(d)

[0020] Among them, x1(r,α,d) and z1(r,α,d) represent the x-axis and z-axis coordinates of the axis of the annulus geometry, respectively, vd(d) represents the function of the vertical depth changing with the well depth d, hd(d) represents the function of the horizontal displacement changing with the well depth d, r and α represent the radial independent variable and circumferential independent variable in the cylindrical coordinate system, respectively.

[0021] According to one embodiment of the present invention, in step three, the inner diameter coordinate function of the annular geometric body is determined according to the following expression:

[0022] x2(r,α,d)={cos(α)×D in -[1-c(d)]×(wd(d)-D in )}×cos(θ(d))

[0023] y2(r,α,d)=sin(α)×D in

[0024] z2(r,α,d)={cos(α)×D in -[1-c(d)]×(wd(d)-Din )}×sin(θ(d))

[0025] Where x2(r,α,d), y2(r,α,d) and z2(r,α,d) represent the coordinates of the point on the inner diameter of the annulus geometry on the x-axis, y-axis and z-axis respectively, D in represents the inner diameter of the annulus geometry, c(d) represents the function of the centering degree changing with the well depth d, wd(d) represents the function of the well diameter changing with the well depth d, θ(d) represents the function of the well inclination changing with the well depth d, r and α represent the radial independent variable and circumferential independent variable in the cylindrical coordinate system, respectively.

[0026] According to one embodiment of the present invention, in step three, the outer diameter coordinate function of the annular geometric body is determined according to the following expression:

[0027] x3(r,α,d)=cos(α)×wd(d)×cos(θ(d))

[0028] y3(r,α,d)=sin(α)×wd(d)

[0029] z3(r,α,d)=cos(α)×wd(d)×sin(θ(d))

[0030] Among them, x3(r,α,d), y3(r,α,d), and z3(r,α,d) represent the coordinates of a point on the outer diameter of the annulus geometry on the x-axis, y-axis, and z-axis, respectively.

[0031] According to one embodiment of the present invention, in step 4, the inner diameter coordinate function of the annular geometric body is transformed according to the following expression:

[0032] x′2(r,α,d)=x2(r,α,d)+x1(r,α,d)

[0033] y′2(r,α,d)=y2(r,α,d)

[0034] z′2(r,α,d)=z2(r,α,d)+z1(r,α,d)

[0035] Among them, x′2(r,α,d), y′2(r,α,d) and z′2(r,α,d) represent the coordinates of the point on the inner diameter of the annulus geometry on the x-axis, y-axis and z-axis after the coordinate transformation, respectively; x2(r,α,d), y2(r,α,d) and z2(r,α,d) represent the coordinates of the point on the inner diameter of the annulus geometry on the x-axis, y-axis and z-axis before the coordinate transformation, respectively; x1(r,α,d) and z1(r,α,d) represent the x-axis and z-axis coordinates of the axis of the annulus geometry, respectively; r and α represent the radial independent variable and circumferential independent variable in the cylindrical coordinate system, respectively; and d represents the well depth.

[0036] According to one embodiment of the present invention, in step 4, the coordinate transformation of the outer diameter coordinate function of the annular geometric body is performed according to the following expression:

[0037] x3′(r,α,d)=x3(r,α,d)+x1(r,α,d)

[0038] y3′(r,α,d)=y3(r,α,d)

[0039] z3′(r,α,d)=z3(r,α,d)+z1(r,α,d)

[0040] Among them, x3′(r,α,d), y3′(r,α,d) and z3′(r,α,d) represent the coordinates of the point on the inner diameter of the annulus geometry on the x-axis, y-axis and z-axis after the coordinate transformation, respectively; x3(r,α,d), y3(r,α,d) and z3(r,α,d) represent the coordinates of the point on the inner diameter of the annulus geometry on the x-axis, y-axis and z-axis before the coordinate transformation, respectively; d represents the well depth; r and α represent the radial independent variable and circumferential independent variable in the cylindrical coordinate system, respectively.

[0041] The oil and gas well annulus geometry model generation method provided by the present invention can accurately describe the annulus geometry of the oil and gas well by constructing the annulus geometry, which is helpful for studying the progress of cementing and completion in oil and gas well engineering. Based on the measured data read, the method also describes the actual changes of the well inclination angle and the centering degree to more accurately construct the annulus geometry model, making it more in line with the actual situation, and thus making the obtained annulus geometry model more in line with the objective reality.

[0042] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following briefly introduces the drawings required in the embodiments or the prior art description:

[0044] Figure 1 It is a schematic diagram of the implementation process of a grid model generation method for a fluid displacement process in a cementing engineering according to an embodiment of the present invention;

[0045] Figure 2 is a schematic diagram of an implementation flow of determining node parameter values ​​of each grid node according to an embodiment of the present invention;

[0046] Figure 3 is a schematic diagram of a related coordinate system in a grid model generation process according to an embodiment of the present invention;

[0047] Figure 4 1 is a schematic diagram of grid coordinate transformation when the well inclination angle is θ according to an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The following will describe the implementation methods of the present invention in detail with reference to the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. It should be noted that as long as there is no conflict, the various embodiments of the present invention and the various features in the embodiments can be combined with each other, and the technical solutions formed are all within the protection scope of the present invention.

[0049] Meanwhile, in the following description, many specific details are set forth for the purpose of explanation to provide a thorough understanding of the embodiments of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the specific details or the specific manner described herein.

[0050] In addition, the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be performed in an order different from that shown here.

[0051] In the existing technology, cementing displacement numerical simulation grid model is usually established through commercial software to study the cementing displacement process. However, there are many disadvantages in using commercial software for grid generation. For example:

[0052] 1) Commercial software cannot use the measured data of the well, and the generated grid model is too simplified

[0053] For the cementing data on site, the parameters such as well diameter, well inclination, and centering are not monotonically changing. Because commercial software cannot use the measured data of the well, the grid it generates can only simplify the model to the situation where the parameters change monotonically, so it is impossible to describe the annular state of the actual parameters.

[0054] 2) Commercial software cannot reasonably encrypt according to the flow rules

[0055] Although commercial software can improve calculation accuracy by encrypting the grid, it is unable to carry out targeted flow direction partition encryption and circumferential orthogonality result adjustment according to the specific flow law of cementing displacement.

[0056] In view of the above problems existing in the prior art, the present invention provides a new method for generating annulus geometry model of oil and gas wells and a cementing method for generating annulus geometry model based on the method. The annulus geometry model generation method can describe the annulus geometry to the greatest extent based on measured data, thereby providing an objective and accurate basis for cementing displacement research.

[0057] Figure 1 A schematic diagram of the implementation flow of the method for generating an oil and gas well annulus geometry model provided in this embodiment is shown.

[0058] like Figure 1 As shown, the method for generating annulus geometry model of oil and gas wells provided in this embodiment first determines the continuous functions of each preset engineering parameter in the preset engineering parameter set as the well depth changes according to the measured data acquired during the cementing process in step S101, thereby obtaining a first function set.

[0059] Specifically, in this embodiment, the measured data obtained by the method in step S101 preferably include data such as well depth, well inclination angle, vertical depth, well diameter, centering degree and casing outer diameter. Of course, in other embodiments of the present invention, according to actual needs, the measured data obtained by the method in step S101 may include only one or several of the listed items, or may include other reasonable parameters, and the present invention is not limited to this.

[0060] Figure 2 A schematic diagram of the implementation flow of determining the first function set in this embodiment is shown.

[0061] like Figure 2 As shown, in this embodiment, when determining the first function set, the method preferably first determines the horizontal displacement of the wellbore trajectory according to the measured data obtained in step S101 in step S201, and then determines the continuous function of each preset engineering parameter changing with the well depth by using the difference method according to the above-mentioned measured data and the horizontal displacement of the wellbore in step S202, thereby obtaining the first function set.

[0062] In this embodiment, the method preferably determines the horizontal displacement of the wellbore trajectory according to the vertical depth and the well inclination angle in the measured data in step S201. For example, the method can determine the horizontal displacement of the wellbore trajectory according to the following expression:

[0063] hd(i)=hd(i-1)+[vd(i)-vd(i-1)]×tan[θ(i)+θ(i-1) / 2] (1)

[0064] Among them, hd represents the horizontal displacement of the borehole trajectory, vd represents the vertical depth, θ represents the well inclination angle, and i and i-1 represent the measured point numbers. In this way, hd(i) and hd(i-1) represent the horizontal displacement of the borehole trajectory of the i-th and i-1-th measuring points, vd(i) and vd(i-1) represent the vertical depth of the i-th and i-1-th measuring points, and θ(i) and θ(i-1) represent the well inclination angle of the i-th and i-1-th measuring points.

[0065] Of course, in other embodiments of the present invention, the method may also adopt other reasonable methods to determine the horizontal displacement of the wellbore trajectory, and the present invention does not specifically limit this.

[0066] In step S202, the method preferably uses a piecewise linear interpolation method to determine the continuous functions of various preset engineering parameters that vary with well depth based on the measured data and the horizontal displacement of the wellbore, thereby obtaining a first function set.

[0067] In this embodiment, for the i-th point, its basis function l i (d) can be determined using the following expression:

[0068]

[0069] Where d represents the well depth, d0 represents the initial well depth, and d i-1 and d i Respectively represent the well depth of the i-1th point and the i-th point, l i (d) represents the basis function of the i-th point.

[0070] In this embodiment, the method preferably further determines the continuous function of each preset engineering parameter changing with the well depth based on the basis function of each point.

[0071] For example, for the horizontal displacement hd, its continuous function hd(d) that varies with well depth can be expressed as:

[0072]

[0073] Among them, hd i represents the horizontal displacement of the i-th point, and n represents the total number of points.

[0074] For the well inclination angle, the continuous function θ(d) that changes with the well depth can be expressed as:

[0075]

[0076] Among them, θ i Represents the well inclination angle of the ith point.

[0077] For vertical depth, the continuous function vd(d) that varies with well depth can be expressed as:

[0078]

[0079] Among them, vd i represents the vertical depth of the ith point.

[0080] For the degree of centering, the continuous function c(d) that varies with well depth can be expressed as:

[0081]

[0082] Among them, c i Indicates the centering degree of the i-th point.

[0083] For horizontal displacement, the continuous function hd(d) that varies with well depth can be expressed as:

[0084]

[0085] Among them, hd i Represents the horizontal displacement of the i-th point.

[0086] For the well diameter, the continuous function wd(d) that varies with the well depth can be expressed as:

[0087]

[0088] Among them, wd i Represents the well diameter of the i-th point.

[0089] Of course, in other embodiments of the present invention, according to actual needs, the above-mentioned basis function can also be expressed by other reasonable functional formulas. At the same time, the method can also use other reasonable methods to determine the continuous function of each preset engineering parameter changing with the well depth. The present invention does not specifically limit this.

[0090] Again Figure 1 As shown, in this embodiment, after obtaining the first function set, the method will determine the axis coordinate function of the annular geometric body according to the first function set in step S102, thereby obtaining the second function set

[0091] like Figure 3 As shown, in the process of generating the annulus geometry model, two sets of coordinate systems are preferably involved, one is the Cartesian coordinate system, and the other is the grid coordinate system. In the Cartesian coordinate system, the x direction is the horizontal direction, the z direction is the vertical direction, the y direction is the direction perpendicular to the xz plane, and the coordinates of the wellhead center are (0, 0, 0).

[0092] The grid coordinate system is a cylindrical coordinate system. In the cylindrical coordinate system, the i direction is the flow direction, and its zero point is the wellhead position; the α direction is the circumferential direction, and its zero point is the zero point position of the circumference as the dial, and its value range is 0° to 360°; the r direction is the radial direction, and its zero point is the axis position, and its value variation range is the inner and outer diameters of the annulus geometry.

[0093] In this embodiment, the annulus geometry axis coordinate function is the wellbore trajectory coordinate function, which represents the axis of the wellbore trajectory. In the Cartesian coordinate system, the annulus geometry axis coordinate function preferably consists of two parts, namely, the relationship between the vertical depth and the well depth and the relationship between the horizontal displacement and the well depth.

[0094] Based on the above principle, in this embodiment, the method can determine the second function set according to the expression:

[0095] x1(r,α,d)=hd(d) (11)

[0096] z1(r,α,d)=vd(d) (12)

[0097] Wherein, x1(r,α,d) and z1(r,α,d) represent the x-axis and z-axis coordinates of the annular geometric body axis, vd(d) represents the function of vertical depth changing with well depth d, hd(d) represents the function of horizontal displacement changing with well depth d, r and α represent the radial independent variable and circumferential independent variable in the cylindrical coordinate system, respectively. For the annular geometric body axis, the value of its radial independent variable is preferably zero.

[0098] Of course, in other embodiments of the present invention, the method may also adopt other reasonable ways to determine the second function set, and the present invention does not specifically limit this.

[0099] like Figure 1 As shown, in this embodiment, the method will also determine the inner diameter coordinate function and the outer diameter coordinate function of the annulus geometry in the three-dimensional coordinate system according to the above-mentioned first function set in step S103, so as to obtain a third function set.

[0100] The inner diameter of the annulus geometry is the diameter of the casing. At the same time, due to the existence of casing eccentricity, the spatial position of the casing will move downward. In addition, the well inclination angles at different wellbore trajectory nodes are different. The cross section of the geometry at this point that is perpendicular to the trajectory line will have an angle with the vertical and horizontal directions. This effect should also be considered when generating the inner diameter of the geometry.

[0101] To this end, in this embodiment, the method in step S103 preferably determines the inner diameter coordinate function of the annulus geometry according to the following expression:

[0102] x2(r,α,d)={cos(α)×Din -[1-c(d)]×(wd(d)-D in )}×cos(θ(d)) (13)

[0103] y2(r,α,d)=sin(α)×D in (14)

[0104] z2(r,α,d)={cos(α)×D in -[1-c(d)]×(wd(d)-D in )}×sin(θ(d)) (15)

[0105] Where x2(r,α,d), y2(r,α,d) and z2(r,α,d) represent the coordinates of the point on the inner diameter of the annulus geometry on the x-axis, y-axis and z-axis respectively, D in represents the inner diameter of the annulus geometry, c(d) represents the function of the centering degree changing with the well depth d, wd(d) represents the function of the well diameter changing with the well depth d, θ(d) represents the function of the well inclination changing with the well depth d, r and α represent the radial independent variable and the circumferential independent variable in the cylindrical coordinate system respectively. For a certain inner diameter coordinate function of the annulus geometry, its radial independent variable r is preferably a given constant value.

[0106] The outer diameter of the annulus geometry is the diameter of the wellbore wall. Figure 4 As shown in the figure, the well inclination angles at different wellbore trajectory nodes are different. The outer diameter of the geometric cross section at this point will have an angle with the vertical and horizontal directions. This influence should also be considered when generating the outer diameter of the geometry.

[0107] To this end, in this embodiment, the method in step S103 preferably determines the outer diameter coordinate function of the annulus geometry according to the following expression:

[0108] x3(r,α,d)=cos(α)×wd(d)×cos(θ(d)) (16)

[0109] y3(r,α,d)=sin(α)×wd(d) (17)

[0110] z3(r,α,d)=cos(α)×wd(d)×sin(θ(d)) (18)

[0111] Wherein, x3(r,α,d), y3(r,α,d) and z3(r,α,d) represent the coordinates of the point on the outer diameter of the annulus geometry on the x-axis, y-axis and z-axis respectively. For the completion coordinate function of the annulus geometry, the value of its radial independent variable r can preferably be determined by actual measurement.

[0112] Of course, in other embodiments of the present invention, the method may also adopt other reasonable methods to implement the third function set according to actual needs, and the present invention does not specifically limit this.

[0113] At the same time, it should be pointed out that the present invention does not limit the specific execution order of the above steps S102 and S103. For example, in different embodiments of the present invention, according to actual needs, the method can first execute step S102 and then step S103, or first execute step S103 and then step S102, or execute step S102 and step S103 at the same time.

[0114] Again Figure 1 As shown, in this embodiment, after obtaining the second function set and the third function set, the method preferably uses the second function set to adjust the third function set in step S104, thereby generating an annulus geometry model of the oil and gas well.

[0115] In this embodiment, the method preferably assigns the horizontal displacement and vertical depth corresponding to the origin of the annular geometry section in step S104, thereby realizing coordinate transformation, and then generating the section at each spatial position. Specifically, the method uses the second function set to adjust the inner diameter coordinate function and the outer diameter coordinate function of the annular geometry under different well depth conditions in step S104, performs coordinate transformation, and thus obtains the annular geometry model.

[0116] For example, in this embodiment, the method can perform coordinate transformation on the inner diameter coordinate function of the annulus geometry according to the following expression:

[0117] x′2(r,α,d)=x2(r,α,d)+x1(r,α,d) (19)

[0118] y′2(r,α,d)=y2(r,α,d) (20)

[0119] z′2(r,α,d)=z2(r,α,d)+z1(r,α,d) (21)

[0120] Among them, x′2(r,α,d), y′2(r,α,d) and z′2(r,α,d) represent the coordinates of the point on the inner diameter of the annulus geometry on the x-axis, y-axis and z-axis after the coordinate transformation, respectively; x2(r,α,d), y2(r,α,d) and z2(r,α,d) represent the coordinates of the point on the inner diameter of the annulus geometry on the x-axis, y-axis and z-axis before the coordinate transformation, respectively; x1(r,α,d) and z1(r,α,d) represent the x-axis and z-axis coordinates of the axis of the annulus geometry, respectively; r and α represent the radial independent variable and circumferential independent variable in the cylindrical coordinate system, respectively; and d represents the well depth.

[0121] Similarly, this method can also transform the coordinate function of the outer diameter of the annulus geometry according to the following expression:

[0122] x3′(r,α,d)=x3(r,α,d)+x1(r,α,d) (22)

[0123] y3′(r,α,d)=y3(r,α,d) (23)

[0124] z3′(r,α,d)=z3(r,α,d)+z1(r,α,d) (24)

[0125] Among them, x3′(r,α,d), y3′(r,α,d) and z3′(r,α,d) represent the coordinates of the point on the inner diameter of the annular geometry on the x-axis, y-axis and z-axis after the coordinate transformation, respectively, and x3(r,α,d), y3(r,α,d) and z3(r,α,d) represent the coordinates of the point on the inner diameter of the annular geometry on the x-axis, y-axis and z-axis before the coordinate transformation.

[0126] It should be pointed out that in other embodiments of the present invention, the method may also use other reasonable methods to adjust the third function set by using the second function set according to actual needs, and the present invention does not specifically limit this.

[0127] In this embodiment, the flow area of ​​the cementing displacement process is an annular space composed of the outer diameter of the casing as the inner layer and the wellbore diameter as the outer layer. The well inclination angle refers to the angle between the central axis of a point in the oil well and the plumb line of the earth, ranging from 0° to 180°. The well inclination angle is used to indicate the inclination of the wellbore trajectory. The centering degree describes the degree to which the casing deviates downward in the wellbore due to the effect of gravity.

[0128] In order to demonstrate the reliability, applicability and advantages of the method for generating annular geometry models of oil and gas wells provided in this embodiment, a certain well is taken as an example for further explanation below.

[0129] Take the logging data of a well as an example. The following table shows the well depth, well inclination, vertical depth, well diameter, and centering data obtained during the cementing process.

[0130] Table 1

[0131]

[0132]

[0133] The outer diameter of the casing of the annulus generated this time is 139.7mm.

[0134] Using the well depth, vertical depth and well inclination angle, this method can calculate the horizontal displacement of the wellbore trajectory according to expression (1), thereby obtaining the data shown in Table 2:

[0135] Table 2

[0136]

[0137] By using interpolation calculation, we can obtain the continuous functions of well inclination, vertical depth, horizontal displacement, well diameter and centering degree as the well depth changes.

[0138] Taking the change of well depth and well inclination angle as an example, the changes of well depth and well inclination angle are as follows:

[0139] Table 3

[0140] well deep 0 … 4500 4525 4550 … 6850 6875 6900 Well inclination angle 0 … 60.40 60.26 60.03 … 88.22 88.24 88.25

[0141] The inner diameter coordinate function of the annulus geometry in the three-dimensional coordinate system is obtained as follows:

[0142] x2(r,α,d)={cos(α)×139.7-[1-c(d)]×(wd(d)-139.7)}×cos(θ(d)) (13)

[0143] y2(r,α,d)=sin(α)×139.7 (14)

[0144] z2(r,α,d)={cos(α)×139.7-[1-c(d)]×(wd(d)-139.7)}×sin(θ(d)) (15)

[0145] From the above description, it can be seen that the oil and gas well annulus geometry model generation method provided by the present invention can accurately describe the oil and gas well annulus geometry by constructing the annulus geometry, which is helpful for studying the progress of cementing and completion in oil and gas well engineering. Based on the measured data read, the method also describes the actual changes in the well inclination angle and the centering degree to more accurately construct the annulus geometry model, making it more in line with the actual situation, and thus making the obtained annulus geometry model more in line with the objective reality.

[0146] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures or processing steps disclosed herein, but should be extended to equivalent substitutions of these features understood by ordinary technicians in the relevant field. It should also be understood that the terms used herein are only used for the purpose of describing specific embodiments and are not meant to be limiting.

[0147] The "one embodiment" or "embodiment" mentioned in the specification means that the specific features, structures or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment" or "embodiment" appearing in various places throughout the specification do not necessarily refer to the same embodiment.

[0148] Although the above examples are used to illustrate the principles of the present invention in one or more applications, it is obvious to those skilled in the art that various modifications can be made in form, usage and implementation details without inventive effort without departing from the principles and ideas of the present invention. Therefore, the present invention is defined by the appended claims.

Claims

1. A method for generating annulus geometric model of oil and gas wells, characterized in that: The method comprises: Step 1: Determine the continuous function of each preset engineering parameter in the preset engineering parameter set as the function of the well depth according to the measured data obtained during the cementing process, and obtain a first function set; Step 2: According to the first function set, determine the axis coordinate function of the annular geometric body in a Cartesian coordinate system to obtain a second function set; Step 3: According to the first function set, determine the inner diameter coordinate function and the outer diameter coordinate function of the annulus geometric body in the Cartesian coordinate system under the three-dimensional coordinate system respectively to obtain a third function set; Step 4: Use the second function set to adjust the third function set to generate an annulus geometry model of the oil and gas well, wherein in the process of generating the annulus geometry model of the oil and gas well, the second function set is used to adjust the inner diameter coordinate function and the outer diameter coordinate function of the annulus geometry under different well depth conditions, respectively, to perform coordinate transformation, thereby obtaining the annulus geometry model.

2. The method according to claim 1, characterized in that In the step 1, determining the horizontal displacement of the wellbore trajectory according to the measured data; According to the measured data and the horizontal displacement of the wellbore, the continuous function of each preset engineering parameter changing with the well depth is determined by using the difference method.

3. The method according to claim 2, characterized in that The horizontal displacement of the wellbore trajectory is determined according to the following expression: hd(i)=hd(i-1)+[vd(i)-vd(i-1)]×tan[θ(i)+θ(i-1) / 2] Among them, hd represents the horizontal displacement of the wellbore trajectory, vd represents the vertical depth, θ represents the well inclination angle, and i and i-1 both represent the measurement point numbers.

4. The method according to claim 2 or 3, characterized in that The preset engineering parameter set includes at least one of the following items: Vertical depth, centering, well inclination, horizontal displacement, and well diameter.

5. The method according to claim 4, characterized in that In the step 2, the second function set is determined according to the following expression: x1(r,α,d)=hd(d) z1(r,α,d)=vd(d) Among them, x1(r,α,d) and z1(r,α,d) represent the x-axis and z-axis coordinates of the axis of the annulus geometry, respectively, vd(d) represents the function of the vertical depth changing with the well depth d, hd(d) represents the function of the horizontal displacement changing with the well depth d, r and α represent the radial independent variable and circumferential independent variable in the cylindrical coordinate system, respectively.

6. The method according to claim 5, characterized in that In step three, the inner diameter coordinate function of the annular geometry is determined according to the following expression: x2(r,α,d)={cos(α)×D in -[1-c(d)]×(wd(d)-D in )}×cos(θ(d)) y2(r,α,d)=sin(α)×D in z2(r,α,d)={cos(α)×D in -[1-c(d)]×(wd(d)-D in )}×sin(θ(d)) Where x2(r,α,d), y2(r,α,d) and z2(r,α,d) represent the coordinates of the point on the inner diameter of the annulus geometry on the x-axis, y-axis and z-axis respectively, D in represents the inner diameter of the annulus geometry, c(d) represents the function of the centering degree changing with the well depth d, wd(d) represents the function of the well diameter changing with the well depth d, θ(d) represents the function of the well inclination changing with the well depth d, r and α represent the radial independent variable and circumferential independent variable in the cylindrical coordinate system, respectively.

7. The method according to claim 6, characterized in that In step three, the outer diameter coordinate function of the annular geometric body is determined according to the following expression: x3(r,α,d)=cos(α)×wd(d)×cos(θ(d)) y3(r,α,d)=sin(α)×wd(d) z3(r,α,d)=cos(α)×wd(d)×sin(θ(d)) Among them, x3(r,α,d), y3(r,α,d), and z3(r,α,d) represent the coordinates of a point on the outer diameter of the annulus geometry on the x-axis, y-axis, and z-axis, respectively.

8. The method according to claim 1, characterized in that In the step 4, the inner diameter coordinate function of the annulus geometry is transformed according to the following expression: x′2(r,α,d)=x2(r,α,d)+x1(r,α,d) y′2(r,α,d)=y2(r,α,d) z′2(r,α,d)=z2(r,α,d)+z1(r,α,d) Among them, x′2(r,α,d), y′2(r,α,d) and z′2(r,α,d) represent the coordinates of the point on the inner diameter of the annulus geometry on the x-axis, y-axis and z-axis after the coordinate transformation, respectively; x2(r,α,d), y2(r,α,d) and z2(r,α,d) represent the coordinates of the point on the inner diameter of the annulus geometry on the x-axis, y-axis and z-axis before the coordinate transformation, respectively; x1(r,α,d) and z1(r,α,d) represent the x-axis and z-axis coordinates of the axis of the annulus geometry, respectively; r and α represent the radial independent variable and circumferential independent variable in the cylindrical coordinate system, respectively; and d represents the well depth.

9. The method according to claim 8, characterized in that In the step 4, the outer diameter coordinate function of the annular geometric body is transformed according to the following expression: x3′(r,α,d)=x3(r,α,d)+x1(r,α,d) y3′(r,α,d)=y3(r,α,d) z3′(r,α,d)=z3(r,α,d)+z1(r,α,d) Among them, x3′(r,α,d), y3′(r,α,d) and z3′(r,α,d) represent the coordinates of the point on the inner diameter of the annulus geometry on the x-axis, y-axis and z-axis after the coordinate transformation, respectively; x3(r,α,d), y3(r,α,d) and z3(r,α,d) represent the coordinates of the point on the inner diameter of the annulus geometry on the x-axis, y-axis and z-axis before the coordinate transformation, respectively; d represents the well depth; r and α represent the radial independent variable and circumferential independent variable in the cylindrical coordinate system, respectively.

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