Horizontal well stratigraphic dip angle calculation method based on real-time tracking

Abstract

A horizontal well stratum dip angle calculation method based on real-time tracking belongs to the technical field of oil exploration and development, and comprises the following steps: firstly, establishing an earthquake work area, comprehensively analyzing curve characteristics of lithology, electrical property, physical property and the like of an adjacent well, counting the thickness of a target layer of the adjacent well, tracking a horizontal well in real time, and emphatically comparing rock debris and curves in the drilling process of the horizontal well; when it is judged that the horizontal well enters a layer, the coordinates (x, y and z) of the top of the layer are recorded when the horizontal well enters the layer, the coordinates of the bottom of the layer are read according to curve change characteristics in the drilling process, and then the stratigraphic dip angle can be rapidly calculated according to a horizontal well stratigraphic dip angle calculation formula based on real-time tracking, and horizontal well drilling is guided. The method has the function of directly predicting or accurately calculating the stratigraphic dip angle of the target layer, the possibility that the horizontal well passes through the middle of the top-bottom interface of the oil and gas reservoir section can be greatly improved, the drilling rate of the horizontal well is guaranteed, the oil-per-ton discovery cost is reduced, benefit utilization is achieved, and profits are increased for enterprises.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum exploration and development, and particularly relates to a method for calculating the inclination of a horizontal well formation based on real-time tracking. Background Art

[0002] Oil and gas exploration and development is a complex process involving many disciplines and a wide range of fields. Faced with exploration costs, how to obtain the most resources with the least investment is one of the most critical factors in the oil exploration and development process. In order to achieve this goal, people began to use horizontal wells to drill oil and gas layers and pursue the maximization of horizontal well reservoir drilling rate. At present, horizontal well drilling has become a conventional drilling technology and is applied to almost all types of oil reservoirs.

[0003] Horizontal well steering technology is based on reservoir prediction and structural dip prediction. It's a new technology that enables real-time monitoring of horizontal wellbore trajectories through a comprehensive understanding and calculation of structural, stratigraphic, and drilling data. In conventional horizontal well steering, formation dip calculation relies primarily on structural maps derived from a combination of wellbore and seismic data. This approach is inaccurate and often reflects the dip of the marker layer, not the target layer. This often leads to horizontal wells missing their target, or, after the well is drilled, the formation dip is unclear, making it impossible to determine the return angle, making it even more difficult to navigate the middle of the top and bottom interfaces of the oil and gas strata. Therefore, if the formation dip of the target layer can be directly predicted or accurately calculated, the likelihood of the horizontal well traversing the middle of the top and bottom interfaces of the oil and gas strata will be greatly increased, ensuring the encounter rate of horizontal wells, reducing the cost per ton of oil discovered, realizing effective utilization, and increasing profits for the company. Summary of the Invention

[0004] In order to solve the above-mentioned problems, the present invention proposes: a method for calculating the inclination of horizontal well formations based on real-time tracking. First, a seismic work area should be established, and the curve characteristics of the adjacent wells such as lithology, electrical properties, and physical properties should be comprehensively analyzed. The thickness of the target layer of the adjacent wells should be counted, and the horizontal wells should be tracked in real time. The cuttings and curves during the horizontal well drilling process should be compared. When it is judged that the horizontal well has entered the layer, the coordinates (x, y, z) of the top of the layer when the horizontal well enters the layer should be recorded. During the drilling process, the coordinates of the bottom of the layer when the layer is exited should be read according to the curve change characteristics. Then, according to the horizontal well formation inclination calculation formula based on real-time tracking, the formation inclination can be quickly calculated to guide the horizontal well drilling.

[0005] Furthermore, the specific implementation process includes the following steps:

[0006] Establish a seismic work area, which should include the wellhead coordinates of the horizontal well design, the coordinates of target A, the coordinates of target B, and the coordinates of the control points on the trajectory. The coordinates should include the plane projection position and depth (x, y, z);

[0007] Where x is the easting coordinate of the ground projection, y is the northing coordinate of the ground projection; z is the altitude depth.

[0008] Furthermore, the specific implementation process also includes the following steps: selecting adjacent wells, comprehensively analyzing their lithology, electrical properties, and physical property curve characteristics, and determining the typical curve and curve characteristics of the target layer.

[0009] Furthermore, the horizontal well drilling process is tracked in real time, focusing on comparing the cuttings and curves during the horizontal well drilling process.

[0010] Furthermore, the specific implementation process also includes the following steps: during the horizontal well drilling process, after entering the target layer from the top through real-time tracking, the coordinates of the entry point (x 入 ,y 入 , z 入 );

[0011] where x 入 is the east coordinate of the ground projection of the entry point, y 入 z is the north coordinate of the ground projection of the entry point; 入 The altitude depth of the entry point.

[0012] Furthermore, the specific implementation process also includes the following steps: during the horizontal well drilling process, after the target layer is drilled through from the bottom, the coordinates of the layer point (x 出 ,y 出 , z 出 );

[0013] where x 出 is the east coordinate of the ground projection of the exit point, y 出 z is the north coordinate of the ground projection of the exit point; 出 The depth above sea level of the exit point.

[0014] Furthermore, the specific implementation process also includes the following steps: using a horizontal well formation dip calculation formula based on real-time tracking to calculate the formation dip and guide the horizontal well drilling angle.

[0015] Furthermore, the formula is:

[0016] Formula 1: β=90+ATAN(ΔH / ΔD)*180 / π

[0017] Formula 2: ΔH=DH

[0018] Formula 3: ΔD = ((x 出 -x 入 ) 2 +(y 出 -y 入 ) 2 )1 / 2

[0019] In the formula, ATAN is the inverse tangent function, D is the difference between the vertical depths of the known well layer top and bottom, H is the difference between the vertical depths of the horizontal well exit point and the vertical depths of the horizontal well entry point, A is the distance between the horizontal well exit point and the wellhead, B is the distance between the horizontal well entry point and the wellhead, and β is the calculated formation dip.

[0020] The beneficial effects of the present invention are as follows: the present invention plays an important role in ensuring and improving the horizontal well drilling rate from the perspective of efficient exploration of oil and gas resources. The present invention has the function of directly predicting or accurately calculating the formation inclination of the target layer, which will greatly increase the possibility of the horizontal well passing through the middle of the top and bottom interfaces of the oil and gas layer section, ensure the horizontal well drilling rate, reduce the discovery cost per ton of oil, realize efficient utilization, and increase profits for the enterprise.

[0021] Since 2022, the method described in this patent has been used to guide the drilling of multiple horizontal wells in the Hong 88 block and Hai 49 block of the Honggang Terrace in the southern Songliao Basin, and achieved good results. The horizontal well drilling rate has increased from the original average of 50% to an average of 83.61%, which has played an important role in the efficient utilization of remaining resources in the southern Songliao Basin. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the cross-sectional projection of the horizontal well trajectory of the present invention and the algorithm diagram of β in the formula of the present invention;

[0023] Figure 2 Schematic diagram of the plane projection of the horizontal well trajectory of the present invention and the algorithm diagram of ΔD in the formula of the present invention;

[0024] Figure 3 It is a schematic diagram of the implementation process of the method for calculating the horizontal well formation inclination based on real-time tracking of the present invention. DETAILED DESCRIPTION

[0025] Example 1

[0026] In order to make the technical means adopted by the present invention and the purpose achieved easy to understand, the present invention is further described below in conjunction with a specific embodiment. A method for calculating the formation dip of a horizontal well based on real-time tracking should first establish a seismic work area, comprehensively analyze the curve characteristics of the lithology, electrical properties, physical properties, etc. of the adjacent well, count the thickness of the target layer of the adjacent well, track the horizontal well in real time, and focus on comparing the rock cuttings and curves during the horizontal well drilling process. When judging whether the horizontal well has entered the layer, the coordinates (x, y, z) of the top of the layer when the horizontal well enters the layer should be recorded. During the drilling process, according to the curve change characteristics, the coordinates of the bottom of the layer when the layer is exited are read. Then, according to the horizontal well formation dip calculation formula based on real-time tracking, the formation dip can be quickly calculated to guide horizontal well drilling. Through the above key steps in the horizontal well formation dip calculation method based on real-time tracking, the formation dip can be accurately, simply and efficiently calculated, the probability of horizontal well drilling out of the layer can be reduced, the drilling rate can be improved, the horizontal well production can be increased, the drilling speed can be increased, the drilling cycle can be reduced, the drilling cost can be saved, and ultimately the horizontal well efficiency of oil and gas resources can be realized.

[0027] The present invention can comprehensively analyze the lithology, electrical properties, physical properties and other curve characteristics of the adjacent well, calculate the thickness of the target layer of the adjacent well, track the horizontal well in real time, and focus on comparing the rock cuttings and curves during the horizontal well drilling process. When judging whether the horizontal well has entered the layer, the coordinates (x, y, z) of the layer top when the horizontal well enters the layer should be recorded. During the drilling process, according to the curve change characteristics, the coordinates of the layer bottom when the layer is exited are read. Then, according to the horizontal well formation dip calculation formula based on real-time tracking, the formation dip can be quickly calculated. The specific implementation of the horizontal well formation dip calculation method based on real-time tracking includes the following steps:

[0028] (1) Establish a seismic work area, which should include the wellhead coordinates of the horizontal well design, the coordinates of target point a, and the coordinates of target point b. If necessary, the coordinates of the control points on the trajectory should also be included. The coordinates should include the plane projection position and depth (x, y, z);

[0029] Where x is the easting coordinate of the ground projection, y is the northing coordinate of the ground projection; z is the altitude depth;

[0030] (2) Select adjacent wells and comprehensively analyze their lithologic, electrical, and physical property curve characteristics to determine the typical curves and curve characteristics of the target layer. Perform real-time tracking during the horizontal well drilling process, focusing on comparing the cuttings and curves during the horizontal well drilling process.

[0031] (3) During the horizontal well drilling process, through real-time tracking, after entering the target layer from the top, the coordinates of the entry point (x 入 ,y 入 , z 入 );

[0032] where x 入 is the east coordinate of the ground projection of the entry point, y入 z is the north coordinate of the ground projection of the entry point; 入 is the altitude depth of the entry point;

[0033] (4) During the horizontal well drilling process, through real-time tracking, after drilling through the target layer from the bottom, the coordinates of the exit point (x 出 ,y 出 , z 出 );

[0034] where x 出 is the east coordinate of the ground projection of the exit point, y 出 z is the north coordinate of the ground projection of the exit point; 出 is the depth above sea level of the exit point;

[0035] (5) Using the horizontal well formation dip calculation formula based on real-time tracking, the formation dip is calculated accurately, simply, and efficiently to guide the horizontal well drilling angle; the formula is:

[0036] Formula 1: β=90+ATAN(ΔH / ΔD)*180 / π

[0037] Formula 2: ΔH=DH

[0038] Formula 3: ΔD = ((x 出 -x 入 ) 2 +(y 出 -y 入 ) 2 ) 1 / 2

[0039] In the formula, ATAN is the inverse tangent function, D is the difference between the vertical depths of the known well layer top and bottom, H is the difference between the vertical depths of the horizontal well exit point and the vertical depths of the horizontal well entry point, A is the distance between the horizontal well exit point and the wellhead, B is the distance between the horizontal well entry point and the wellhead, and β is the calculated formation dip.

[0040] Example 2

[0041] In order to make the key links, core technologies, implementation effects and advantages of the present invention clearer, the present invention will be further described in detail below in accordance with the specific process of the present invention, taking an actual three-dimensional seismic work area in the southern Songliao Basin as an example, and combined with the accompanying drawings.

[0042] (1) Establish a seismic work area, which includes the design wellhead coordinates of the horizontal well Well-p, the coordinates of target point a, and the coordinates of target point b. The coordinates should include the plane projection position and depth (x, y, z);

[0043] Where x is the easting coordinate of the ground projection, y is the northing coordinate of the ground projection; z is the altitude depth;

[0044] (2) Select adjacent wells and comprehensively analyze their lithologic, electrical, and physical property curve characteristics to determine the typical curve and curve characteristics of the target layer. Perform real-time tracking during the horizontal well drilling process, focusing on comparing the cuttings and curves during the horizontal well drilling process. Through comparison, the thickness of the target layer is determined to be 5 m.

[0045] (3) During the drilling of the horizontal well Well-p, by real-time tracking and comparing the typical curves and curve characteristics of the target layer of the known adjacent well Well, it is determined that the target layer is entered from the top and the coordinates of the entry point are recorded (1040, 1030, 1005);

[0046] Among them, 1040 is the east coordinate of the ground projection of the entry point, 1030 is the north coordinate of the ground projection of the entry point; 1005 is the altitude depth of the entry point;

[0047] (4) During the drilling of the horizontal well, through real-time tracking, after the target layer is drilled through from the bottom, the coordinates of the layer point (1000, 1000, 1030) are recorded;

[0048] Among them, 1000 is the east coordinate of the ground projection of the exit point, 1000 is the north coordinate of the ground projection of the exit point; 1030 is the altitude depth of the exit point;

[0049] (5) Using the horizontal well formation dip calculation formula based on real-time tracking, the formation dip can be accurately, simply, and efficiently calculated to be 88.47 degrees, which is used to guide the angle during horizontal well drilling; the formula is:

[0050] Formula 1: β=90+ATAN(ΔH / ΔD)*180 / π

[0051] Formula 2: ΔH=DH

[0052] Formula 3: ΔD = ((x 出 -x 入 ) 2 +(y 出 -y 入 ) 2 ) 1 / 2

[0053] In the formula, ATAN is the inverse tangent function, D is the difference between the vertical depths of the known well layer top and bottom, H is the difference between the vertical depths of the horizontal well exit point and the vertical depths of the horizontal well entry point, A is the distance between the horizontal well exit point and the wellhead, B is the distance between the horizontal well entry point and the wellhead, and β is the calculated formation dip. Figure 1 ,like Figure 2 ,like Figure 3 .

[0054] Figure 1It is a schematic diagram of the horizontal well trajectory profile projection and an algorithm diagram of β in the formula of the present invention. The figure is a model diagram that clearly describes three contents: one is the relationship between the formation and the adjacent well revealed during the horizontal well drilling process; the second is how to read the coordinates of the entry point and exit point in the patent claims during the horizontal well drilling process; and the third is the geometric relationship between the formation inclination and various parameters.

[0055] Figure 2 This is a schematic diagram of the plane projection of the horizontal well trajectory and the algorithm diagram of ΔD in the formula of the present invention. The figure is a schematic diagram that clearly describes one content, namely the calculation method of the projection distance between the entry point and the exit point on the plane and the relationship between various parameters.

[0056] Figure 3 This is a schematic diagram of the implementation process of the horizontal well formation dip calculation method based on real-time tracking. The figure is a reference diagram for the calculation example, which clearly describes the calculated formation dip size and calculation formula under given data conditions.

[0057] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed in the present invention, who makes equivalent replacements or changes based on the technical solutions and concepts of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for calculating the formation dip of a horizontal well based on real-time tracking, characterized in that: First, a seismic work area should be established, and the lithology, electrical properties, physical properties and other curve characteristics of the adjacent wells should be comprehensively analyzed. The thickness of the target layer of the adjacent wells should be counted, and the horizontal wells should be tracked in real time. The cuttings and curves during the horizontal well drilling process should be compared. When it is judged that the horizontal well has entered the layer, the coordinates (x, y, z) of the top of the layer when the horizontal well enters the layer should be recorded. During the drilling process, the coordinates of the bottom of the layer when the layer is exited should be read according to the curve change characteristics. Then, according to the horizontal well formation dip calculation formula based on real-time tracking, the formation dip can be quickly calculated to guide horizontal well drilling.

2. The method for calculating horizontal well formation inclination based on real-time tracking according to claim 1, characterized in that: The specific implementation process includes the following steps: Establish a seismic work area, which should include the wellhead coordinates of the horizontal well design, the coordinates of target A, the coordinates of target B, and the coordinates of the control points on the trajectory. The coordinates should include the plane projection position and depth (x, y, z); Where x is the easting coordinate of the ground projection, y is the northing coordinate of the ground projection; z is the altitude depth.

3. The method for calculating the horizontal well formation dip angle based on real-time tracking according to claim 2, wherein: The specific implementation process also includes the following steps: selecting adjacent wells, comprehensively analyzing their lithology, electrical properties, and physical property curve characteristics, and determining the typical curve and curve characteristics of the target layer.

4. The method for calculating horizontal well formation inclination based on real-time tracking according to claim 3, characterized in that: Real-time tracking of the horizontal well drilling process is carried out, with a focus on comparing the cuttings and curves during the horizontal well drilling process.

5. The method for calculating horizontal well formation inclination based on real-time tracking according to claim 4, characterized in that: The specific implementation process also includes the following steps: During the horizontal well drilling process, through real-time tracking, after entering the target layer from the top, the coordinates of the entry point (x 入 ,y 入 , z 入 ); where x 入 is the east coordinate of the ground projection of the entry point, y 入 z is the north coordinate of the ground projection of the entry point; 入 The altitude depth of the entry point.

6. The method for calculating horizontal well formation inclination based on real-time tracking according to claim 5, characterized in that: The specific implementation process also includes the following steps: During the horizontal well drilling process, through real-time tracking, after the target layer is drilled through from the bottom, the coordinates of the exit point (x 出 ,y 出 , z 出 ); where x 出 is the east coordinate of the ground projection of the exit point, y 出 z is the north coordinate of the ground projection of the exit point; 出 The depth above sea level of the exit point.

7. The method for calculating horizontal well formation inclination based on real-time tracking according to claim 6, characterized in that: The specific implementation process also includes the following steps: using a horizontal well formation dip calculation formula based on real-time tracking to calculate the formation dip and guide the horizontal well drilling angle.

8. The method for calculating horizontal well formation inclination based on real-time tracking according to claim 7, characterized in that: in, The formula is: Formula 1: β=90+ATAN(ΔH / ΔD)*180 / π Formula 2: ΔH=DH Formula 3: ΔD=((x 出 -x 入 ) 2 +(y 出 -y 入 ) 2 ) 1 / 2 In the formula, ATAN is the inverse tangent function, D is the difference between the vertical depths of the known well layer top and bottom, H is the difference between the vertical depths of the horizontal well exit point and the vertical depths of the horizontal well entry point, A is the distance between the horizontal well exit point and the wellhead, B is the distance between the horizontal well entry point and the wellhead, and β is the calculated formation dip.

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