Horizontal well straightening comparison method and device considering formation dip angle

Abstract

The present application relates to the technical field of geophysical exploration, and more particularly to a horizontal well straightening comparison method and device considering formation dip, the method comprising: obtaining the while-drilling measurement information of a target horizontal well, a reference well of the target horizontal well, and the formation dip of a target layer; determining the true vertical depth and horizontal distance of a target target point of the target horizontal well from a starting point of a wellhead according to the while-drilling measurement information; determining the apparent vertical depth of the target target point according to the formation dip, the true vertical depth, and the horizontal distance; straightening the trajectory of the target horizontal well according to the apparent vertical depth in combination with the well logging curve of the reference well; and comparing the straightened target horizontal well with the reference well, thereby completing the straightening comparison of the target horizontal well. The present application solves the problem of low accuracy of horizontal section straightening comparison results in the horizontal well steering process under complex geological conditions, which leads to a decrease in the horizontal well drilling rate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geophysical exploration, and in particular to a horizontal well straightening comparison method and device considering formation dip angle. BACKGROUND

[0002] Horizontal wells have the advantages of large drainage area, high single well production, large penetration, high degree of reserve utilization, and the ability to avoid obstacles and harsh environments, providing an effective means for the effective exploitation of thin and ultra-thin oil layers. Horizontal well geosteering technology has developed rapidly and can control the horizontal section trajectory within a horizontal range of vertical depth variation <0.5m and swing <2.5m. The design horizontal well reservoir thickness selection standard has been reduced from more than 6m to about 1m at present. The core of horizontal well steering technology is the straightening and comparison technology of horizontal well trajectory.

[0003] The currently available literature and patents related to the straightening and comparison of multiple horizontal wells are mainly based on the straightening of the inclination angle and azimuth angle of the measurement data while drilling. Therefore, the horizontal well straightening and comparison method has the following deficiencies: the influence of the inclination angle and the formation dip angle is not considered. For the same true thickness of the formation, the formation measurement thickness, vertical thickness, and apparent vertical thickness obtained under different formation dip angles are different. The greater the dip angle, the greater the influence. Therefore, due to the influence of the formation dip angle, the accuracy of the straightening and comparison prediction of the horizontal section is affected. SUMMARY

[0004] The present application provides a horizontal well straightening comparison method and device considering formation dip angle, to solve the problem that the accuracy of the horizontal section straightening and comparison result is low during the horizontal well steering process due to the influence of the formation dip angle, which reduces the horizontal well drilling rate under the current complex geological conditions.

[0005] According to one aspect of the present application, a horizontal well straightening comparison method considering formation dip angle is provided, comprising:

[0006] obtaining the measurement-while-drilling information of the target horizontal well, the reference well of the target horizontal well, and the formation dip angle of the target layer;

[0007] determining the true vertical depth and horizontal distance of the target target point of the target horizontal well from the starting point of the wellhead according to the measurement-while-drilling information;

[0008] determining the apparent vertical depth of the target target point according to the formation dip angle, the true vertical depth, and the horizontal distance, and straightening the trajectory of the target horizontal well according to the apparent vertical depth combined with the logging curve of the reference well;

[0009] comparing the straightened target horizontal well with the reference well, thereby completing the straightening and comparison of the target horizontal well.

[0010] Preferably, the measurement-while-drilling information at least includes: inclination and target horizontal well trajectory length.

[0011] Preferably, the method for determining the true vertical depth and horizontal distance of the target target point of the target horizontal well from the starting point of the wellhead according to the measurement-while-drilling information comprises:

[0012] the true vertical depth = target horizontal well trajectory length*cos(inclination);

[0013] the horizontal distance = target horizontal well trajectory length*sin(inclination).

[0014] Preferably, the method for determining the apparent vertical depth of the target target point according to the formation dip angle, the true vertical depth and the horizontal distance comprises:

[0015] the apparent vertical depth of the starting target point is equal to the true vertical depth of the starting target point;

[0016] if the formation dip angle of the target target point is the same as that of the adjacent upper target point, then:

[0017] the apparent vertical depth of the target target point = the true vertical depth of the target target point + (the horizontal distance of the target target point - the horizontal distance of the adjacent upper target point)*tan(the formation dip angle of the target target point) + the offset distance of the upper target point;

[0018] if the formation dip angle of the target target point is different from that of the adjacent upper target point, then:

[0019] the apparent vertical depth of the target target point = the true vertical depth of the target target point + (the horizontal distance of the target target point - the horizontal distance of the formation dip angle change point)*tan(the formation dip angle of the target target point) + (the horizontal distance of the formation dip angle change point - the horizontal distance of the upper target point of the formation dip angle change point)*tan(the formation dip angle of the upper target point of the formation dip angle change point) + the offset distance of the upper target point of the formation dip angle change point.

[0020] Preferably, the calculation formula of the offset distance comprises:

[0021] the offset distance = the true vertical depth - the apparent vertical depth.

[0022] Preferably, before the reference well of the target horizontal well is obtained, the method for determining the reference well of the target horizontal well comprises:

[0023] selecting a well which is in the same area as the target horizontal well, and has the same sedimentary environment, continuous core of the target layer and / or meets the requirements of the borehole condition as the preferred well;

[0024] selecting the well closest to the target horizontal well from all the preferred wells as the reference well.

[0025] Preferably, the method for straightening the target horizontal well trajectory according to the apparent vertical depth in combination with the logging curve of the reference well comprises the following steps.

[0026] The curve in the target horizontal well logging curve that responds most obviously to the characteristics of the target layer is selected as the comparison curve, and the comparison curve is compared and analyzed with the logging curve of the corresponding reference well, and the target horizontal well trajectory is straightened in segments in combination with the apparent vertical depth.

[0027] According to an aspect of the present disclosure, a horizontal well straightening and comparison device considering the formation dip angle is provided, comprising:

[0028] An acquisition unit is configured to acquire the measurement-while-drilling information of a target horizontal well, a reference well of the target horizontal well, and a formation dip angle of a target layer.

[0029] A true vertical depth and horizontal distance determination unit is configured to determine the true vertical depth and horizontal distance of a target target point of the target horizontal well from a starting point at the wellhead according to the measurement-while-drilling information.

[0030] A well trajectory straightening unit is configured to determine the apparent vertical depth of the target target point according to the formation dip angle, the true vertical depth, and the horizontal distance, and to straighten the target horizontal well trajectory according to the apparent vertical depth in combination with the logging curve of the reference well.

[0031] A comparison unit is configured to compare the straightened target horizontal well with the reference well, thereby completing the straightening and comparison of the target horizontal well.

[0032] The present application has at least the following beneficial effects:

[0033] The present application provides a horizontal well straightening and comparison method and device considering the formation dip angle, which determines the apparent vertical depth of the target target point through the formation dip angle, the true vertical depth, and the horizontal distance of the target target point, straightens the target horizontal well through the apparent vertical depth and the logging curve of the reference well, eliminates the influence of the formation dip angle, uses the apparent vertical depth in the straight well mode for formation comparison, and improves the horizontal section comparison and target entry accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0034] The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present application and, together with the specification, serve to explain the technical solutions of the present application.

[0035] Figure 1 A flowchart of a horizontal well straightening and comparison method considering the formation dip angle according to an embodiment of the present application is shown;

[0036] Figure 2 A cross-sectional view of a reference well according to an embodiment of the present application is shown;

[0037] Figure 3 FIG. 1 shows a schematic diagram of a formation dip and hole inclination according to an embodiment of the present application;

[0038] Figure 4 FIG. 3 shows a schematic diagram of a target horizontal well apparent vertical depth according to an embodiment of the present application;

[0039] Figure 5 FIG. 5 shows a schematic diagram of a horizontal well trajectory in different dip formation cases according to an embodiment of the present application. EMBODIMENTS

[0040] Various exemplary embodiments, features, and aspects of the present application will be described herein below with reference to the accompanying drawings. The same reference numbers in different drawings represent the same or similar elements. Although various aspects of embodiments are illustrated in the drawings, the drawings are not necessarily drawn to scale unless specifically noted.

[0041] The term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0042] The term "and / or" used herein only means an association relationship of associated objects, and means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the term "at least one" herein means any one of a plurality or any combination of at least two of a plurality, for example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0043] In addition, in order to better illustrate the present application, numerous specific details are given in the following detailed description. Those skilled in the art will understand that the present application can be implemented without certain specific details. In some examples, methods, means, elements and circuits well known to those skilled in the art are not described in detail in order to highlight the main idea of the present application.

[0044] Figure 1 FIG. 1 shows a schematic diagram of a formation dip and hole inclination according to an embodiment of the present application; Figure 2 FIG. 1 shows a schematic diagram of a formation dip and hole inclination according to an embodiment of the present application; Figure 3 FIG. 1 shows a schematic diagram of a formation dip and hole inclination according to an embodiment of the present application; Figure 4 FIG. 3 shows a schematic diagram of a target horizontal well apparent vertical depth according to an embodiment of the present application; Figures 1-5As shown, a horizontal well straightening comparison method considering formation dip angle comprises the following steps: S01: acquiring the while-drilling measurement information of a target horizontal well, a reference well of the target horizontal well, and a formation dip angle of a target layer; S02: determining the true vertical depth and horizontal distance of a target target point of the target horizontal well from a starting point of a wellhead according to the while-drilling measurement information; S03: determining the apparent vertical depth of the target target point according to the formation dip angle, the true vertical depth, and the horizontal distance, and straightening the target horizontal well trajectory according to the apparent vertical depth and in combination with the logging curve of the reference well; and S04: comparing the straightened target horizontal well trajectory with the reference well to complete the straightening comparison of the target horizontal well.

[0045] The horizontal well straightening comparison method considering formation dip angle provided by the embodiment of the present application specifically comprises the following steps:

[0046] S01: acquiring the while-drilling measurement information of a target horizontal well, a reference well of the target horizontal well, and a formation dip angle of a target layer.

[0047] In the present application, the while-drilling measurement information at least comprises a deviation angle and a target horizontal well trajectory length.

[0048] In the present application, before the reference well of the target horizontal well is acquired, the reference well of the target horizontal well is determined by the method comprising: selecting a well in the same area as the target horizontal well, and having the same deposition environment, continuous target layer core, and / or meeting the requirements of borehole conditions as the preferred well; and selecting the well closest to the target horizontal well from all the preferred wells as the reference well.

[0049] In the embodiment of the present application, according to the actual underground geological conditions of the horizontal well, a vertical well closest to the horizontal well, having the same deposition environment, continuous target layer lithology, and good borehole conditions in the same area is selected as the reference vertical well for the straightening comparison of the horizontal well.

[0050] Figure 2 The columnar profile of the preferred reference well in the embodiment of the present application is shown, which is a vertical well, 150 meters away from the wellhead of the horizontal well, having the same deposition environment, continuous target layer lithology with the horizontal well, and good borehole conditions.

[0051] The while-drilling measurement information comprises the azimuth angle and other while-drilling measurement data besides the deviation angle, and the while-drilling logging data such as gamma and resistivity are also collected, the while-drilling measurement data are important data in the straightening process of the horizontal well, and the while-drilling logging data are important comparison basis in the well data comparison process.

[0052] Figure 3The schematic diagram of the stratum dip angle and the well inclination angle between the horizontal well trajectory and the inclined target layer is shown, and the schematic diagram between different intersection angles and different thicknesses is also indicated. In the diagram, the intersection angle between the target layer m and the horizontal line is the stratum dip angle a; the intersection angle between the trajectory line and the stratum is the cutting angle b; the intersection angle between the trajectory line and the vertical line is the well inclination angle c; the distance from the point where the trajectory enters the target layer to the intersection point of the vertical line and the bottom of the target layer is the apparent vertical thickness d; the distance from the point where the trajectory enters the target layer to the point where the trajectory exits the target layer is the measured thickness e; the vertical distance from the point where the trajectory enters the target layer to the point where the trajectory exits the target layer is the vertical thickness f; and the vertical distance between the top and bottom boundaries of the target layer is the stratum thickness g.

[0053] Due to the influence of the well inclination angle and the stratum dip angle, the stratum measured thickness, the vertical thickness and the apparent vertical thickness of the same true thickness stratum are different under different stratum dip angles, and the greater the dip angle, the greater the influence. Therefore, the influence of the dip angle on the prediction accuracy of the horizontal section comparison is caused. In order to eliminate the influence of the stratum dip angle and the well inclination angle as much as possible, the depth of the adjacent well and the target well is corrected, and the apparent vertical thickness under the straight well mode is used to perform the stratum comparison.

[0054] Step S02: determining the true vertical depth and the horizontal distance of the target target point of the target horizontal well from the starting point of the wellhead according to the measurement-while-drilling information.

[0055] In the present application, the method for determining the true vertical depth and the horizontal distance of the target target point of the target horizontal well from the starting point of the wellhead according to the measurement-while-drilling information comprises:

[0056] The true vertical depth = the length of the target horizontal well trajectory * cos (the well inclination angle) (1);

[0057] The horizontal distance = the length of the target horizontal well trajectory * sin (the well inclination angle) (2).

[0058] In the embodiment of the present application, under the condition that the azimuth angle is unchanged, the true vertical depth and the horizontal distance calculation formula of the target point are as formula (1) and formula (2).

[0059] As Figure 4 The schematic diagram of the apparent vertical depth of each target point in the target well in the embodiment of the present application is shown. In the diagram, point A is the starting point of the wellhead, and the drill bit drills into the target stratum m. When reaching the B target point, the measurement-while-drilling information of the B target point is obtained, that is, the well inclination angle and the well trajectory length corresponding to the B target point, which are substituted into formula (1) and (2) to calculate the true vertical depth and the horizontal distance corresponding to the B target point. The horizontal distance of the target point is the horizontal distance between the target point and the vertical line, that is, the distance between the B target point and B'; and the true vertical depth of the target point is the vertical distance between the starting point and the horizontal line of the target point, that is, the distance between the starting point A and B'.

[0060] Step S03: determining the apparent vertical depth of the target target point according to the formation dip angle, the true vertical depth and the horizontal distance, and rectifying the target horizontal well trajectory according to the apparent vertical depth and in combination with the logging curve of the reference well.

[0061] In the present application, the method for determining the apparent vertical depth of the target target point according to the formation dip angle, the true vertical depth and the horizontal distance comprises:

[0062] The apparent vertical depth of the starting target point is equal to the true vertical depth of the starting target point;

[0063] If the formation dip angle corresponding to the target target point is the same as that of the previous target point, then:

[0064] The apparent vertical depth of the target target point = the true vertical depth of the target target point + (the horizontal distance of the target target point - the horizontal distance of the previous target point) * tan the formation dip angle of the target target point + the offset distance of the previous target point (3).

[0065] If the formation dip angle corresponding to the target target point is different from that of the previous target point, then:

[0066] The apparent vertical depth of the target target point = the true vertical depth of the target target point + (the horizontal distance of the target target point - the horizontal distance of the formation dip angle change point) * tan the formation dip angle of the target target point + (the horizontal distance of the formation dip angle change point - the horizontal distance of the previous target point of the formation dip angle change point) * tan the formation dip angle of the previous target point of the formation dip angle change point + the offset distance of the previous target point of the formation dip angle change point (4).

[0067] In the present application, the calculation formula of the offset distance comprises: offset distance = true vertical depth - apparent vertical depth.

[0068] In the embodiment of the present application, the formation dip angle is positive when it inclines upward and negative when it inclines downward; the different formation dip angles through which the target horizontal well trajectory passes are x, y, z and k in sequence.

[0069] The apparent vertical depth of the A target point (the starting point) = the true vertical depth of the A target point, and the offset distance of the A target point = 0.

[0070] Since the tendency of the formation dip angle corresponding to the B target point is the same as that of the formation dip angle corresponding to the A target point, then:

[0071] The apparent vertical depth of the B target point = the true vertical depth of the B target point + (the horizontal distance of the B target point - the horizontal distance of the A target point) * tan the formation dip angle x corresponding to the B target point.

[0072] Since the C target point and the B target point are at the same formation dip angle, then:

[0073] The apparent vertical depth of the C target point = the true vertical depth of the C target point + (the horizontal distance of the C target point - the horizontal distance of the B target point) * tan the formation dip angle x corresponding to the C target point + the offset distance of the B target point.

[0074] Because the C target point is the inflection point of the dip angles of two strata, the C target point and the D target point are at the same strata dip angle, so:

[0075] The apparent vertical depth of the D target point is D target point true vertical depth + (D target point horizontal distance - C target point horizontal distance) * tan D target point corresponding strata dip angle y + C target point offset distance.

[0076] Because the E target point and the D target point are at the same strata dip angle, so:

[0077] The apparent vertical depth of the E target point is E target point true vertical depth + (E target point horizontal distance - D target point horizontal distance) * tan E target point corresponding strata dip angle y + D target point offset distance.

[0078] Because the E target point is the inflection point of the dip angles of two strata, the E target point and the F target point are at the same strata dip angle, so:

[0079] The apparent vertical depth of the F target point is F target point true vertical depth + (F horizontal distance - E horizontal distance) * tan F target point corresponding strata dip angle z + E target point offset distance.

[0080] Because the G target point corresponding strata dip angle and the F target point strata dip angle are different, so:

[0081] The apparent vertical depth of the G target point is G target point true vertical depth + (G target point horizontal distance - E target point horizontal distance) * tan G target point corresponding strata dip angle k + (E target point horizontal distance - D target point horizontal distance) * tan E target point corresponding strata dip angle y + D target point offset distance.

[0082] In formula (4), the strata dip angle change point is the last strata dip angle change point of the target point, that is, the last target point of the G target point is F, but the strata dip angle at F does not change, so the last strata dip angle change point of the G target point is the E target point, that is, the inflection point of the well trajectory, and generally the inflection point of the well trajectory corresponds to the strata dip angle change point.

[0083] In the application, the method for straightening the target horizontal well trajectory according to the apparent vertical depth and combining the logging curve of the reference well comprises the following steps: selecting a curve that responds most obviously to the characteristics of the target layer in the target horizontal well logging curve as a comparison curve, comparing and analyzing the comparison curve with the logging curve of the corresponding reference well, and combining the apparent vertical depth to segmentally straighten the target horizontal well trajectory.

[0084] In this embodiment of the invention, when the drill bit reaches each target point, the apparent vertical depth corresponding to that target point is calculated according to the above method. Combined with the corresponding reference well logging curve, the accurate position of the drill bit in the target layer is determined, thereby guiding the drill bit position and the horizontal well trajectory, and straightening the horizontal well trajectory to ensure it is as close as possible to the target layer. The straightening process involves: segmenting the well using adjacent target points; converting the target horizontal well curve to a vertical well position based on the apparent vertical depth of the target point; and finally straightening the horizontal well curve into a vertical well curve.

[0085] The logging curves in the target horizontal well that show obvious characteristic responses to the target layer are used as comparison curves, such as gamma, resistivity, and sonic transit time curves. The horizontal section is segmented and straightened according to the apparent vertical depth corresponding to the target point. The logging curves of the target horizontal well with obvious characteristic responses after straightening, i.e., the comparison curves, are compared and analyzed with the logging curves corresponding to the reference well to determine the accurate location of the target point in the horizontal well segment.

[0086] For a single horizontal well, different formation dip angles and well inclination angles are used to divide the well into different segments. The dip angle information of different segments is read, and the apparent vertical thickness of each segment is calculated according to the segment. The calculated apparent vertical thickness of each segment is accumulated or interpolated to obtain the apparent vertical thickness map of the entire well.

[0087] The apparent vertical depths at each point calculated above are uniformly classified as the apparent vertical thickness depths in the vertical direction up to point A. The dip angle of the strata is positive for downdip and negative for updip. When calculating the apparent vertical thickness of the next segment, the apparent vertical offset of the previous segments, i.e., the offset distance, should be accumulated.

[0088] Since each well is located in a different structural position and the formation development and occurrence are not the same, the horizontal well trajectory segmentation process needs to consider both updip and downdip formations. For each case, the trajectory needs to consider whether the target layer is updip or downdip, as well as whether the vertical depth increases when the sandstone is turned back, and eight other actual situations.

[0089] like Figure 5 As shown in Figure (I), the formation dips downwards, and the trajectory cuts down through the formation; Figure (II) shows the formation dips upwards, and the trajectory cuts down through the formation; Figure (III) shows the formation dips downwards, and the trajectory cuts upwards through the formation; Figure (IV) shows the formation dips upwards, and the trajectory cuts upwards through the formation; Figure (V) shows the formation dips downwards, the vertical depth increases, and sandstone is turned back; Figure (VI) shows the formation dips downwards, the vertical depth decreases, and sandstone is turned back; Figure (VII) shows the formation dips upwards, the vertical depth decreases, and sandstone is turned back; Figure (VIII) shows the formation dips upwards, the vertical depth increases, and sandstone is turned back. The method of this invention fully considers and includes the above eight situations, and can calculate the accurate apparent vertical depth corresponding to each target point, thereby making the horizontal well trajectory straightening more accurate.

[0090] Step S04: comparing the straightened target horizontal well with the reference well, and completing the straightening comparison of the target horizontal well.

[0091] In the embodiment of the present application, the logging curves of all the straightened target horizontal wells are compared with the logging curves of the reference well, the position of the target horizontal well section is determined, and data support is provided for the next step of perforation and fracturing scheme design.

[0092] It can be understood that the above-mentioned various method embodiments of the present application can be combined with each other to form combined embodiments without deviating from the principle logic. Due to the limited space, the present application will not be described again.

[0093] The execution subject of the horizontal well straightening comparison method considering the formation dip angle can be a horizontal well straightening comparison device considering the formation dip angle. For example, the horizontal well straightening comparison method considering the formation dip angle can be executed by a terminal device or a server or other processing device. The terminal device can be a user equipment (UE), a mobile device, a user terminal, a terminal, a cellular phone, a cordless phone, a personal digital assistant (PDA), a handheld device, a computing device, a vehicle-mounted device, a wearable device, etc. In some possible implementation manners, the horizontal well straightening comparison method considering the formation dip angle can be realized by a processor calling computer readable instructions stored in a memory.

[0094] Those skilled in the art can understand that in the above-mentioned method of the specific embodiment, the writing order of each step does not mean a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.

[0095] The present application provides a horizontal well straightening comparison device considering the formation dip angle, comprising: an acquisition unit configured to acquire measurement-while-drilling information of a target horizontal well, a reference well of the target horizontal well, and a formation dip angle of a target layer; a true vertical depth and horizontal distance determination unit configured to determine a true vertical depth and a horizontal distance of a target target point of the target horizontal well from a starting point of a wellhead according to the measurement-while-drilling information; a well trajectory straightening unit configured to determine a apparent vertical depth of the target target point according to the formation dip angle, the true vertical depth and the horizontal distance, and to straighten a trajectory of the target horizontal well according to the apparent vertical depth and in combination with logging curves of the reference well; and a comparison unit configured to compare the straightened target horizontal well with the reference well, thereby completing the straightening comparison of the target horizontal well.

[0096] In some embodiments, the apparatus provided by the embodiments of the present application has functions or includes modules and units which can be used to execute the methods described in the above method embodiment, and the specific implementation can be referred to the description of the above method embodiment.

[0097] The present application solves the problem that the horizontal section straightening in the horizontal well guiding process is not accurate under complex geological conditions, which reduces the horizontal well drilling rate. By calculating the apparent vertical depth of the target point, the accurate position of the drill bit can be determined during drilling, guiding the subsequent horizontal well guiding. After drilling, it can assist in perforation scheme design.

[0098] The present application introduces the concept of formation dip angle, combines the horizontal well trajectory information with the formation dip angle information, eliminates the influence of the formation dip angle and the inclination angle, considers the two cases of formation up-dip and down-dip, increases the cases of out-layer and down-layer on the trajectory and the trajectory layer return, uses the apparent vertical thickness in the straight well mode to perform the formation comparison, and returns the horizontal well trajectory to the correct depth and performs the curve comparison with the reference well, thereby effectively improving the horizontal section comparison and the target entering precision and the success rate of the horizontal well geological guiding.

[0099] The above has described the embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, practical application or technical improvement in the market, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A horizontal well alignment and correlation method considering formation dip angle, characterized in that, include: Obtain the measurement-while-drilling information of the target horizontal well, the reference well of the target horizontal well, and the dip angle of the target formation; The measurement-while-drilling information includes at least: well inclination angle and target horizontal well trajectory length; Based on the drilling measurement information, the true vertical depth and horizontal distance of the target point of the target horizontal well from the wellhead starting point are determined. The method includes: the true vertical depth = target horizontal well trajectory length * cos(well inclination angle); the horizontal distance = target horizontal well trajectory length * sin(well inclination angle). The apparent vertical depth of the target point is determined based on the dip angle, true vertical depth, and horizontal distance. The method includes: the apparent vertical depth of the initial target point is equal to its true vertical depth; if the dip angle of the target point is the same as the dip angle of its adjacent previous target point, then: apparent vertical depth of the target point = true vertical depth of the target point + (horizontal distance of the target point - horizontal distance of the adjacent previous target point) * tan(dip angle of the target point) + offset distance of the previous target point; if the dip angle of the target point is different from the dip angle of its adjacent previous target point, then: apparent vertical depth of the target point = true vertical depth of the target point + (horizontal distance of the target point - horizontal distance of the point where the dip angle changes) * tan(dip angle of the target point) + (horizontal distance of the point where the dip angle changes - horizontal distance of the previous target point) * tan(dip angle of the previous target point) + offset distance of the previous target point. The formula for calculating the offset distance includes: Offset distance = True vertical depth - Apparent vertical depth; Based on the apparent vertical depth and the logging curve of the reference well, the trajectory of the target horizontal well is straightened. The straightened target horizontal well is compared with the reference well to complete the straightening comparison of the target horizontal well.

2. The horizontal well alignment and correlation method considering formation dip angle according to claim 1, characterized in that: The measurement-while-drilling information also includes azimuth, gamma, and resistivity logging-while-drilling data.

3. The horizontal well alignment and comparison method considering formation dip angle according to claim 1, characterized in that, The method for determining the reference well of the target horizontal well before obtaining the reference well of the target horizontal well includes: The preferred wells are those located in the same area as the target horizontal well, with the same sedimentary environment, continuous core of the target layer, and / or wellbore conditions that meet the requirements. The well closest to the target horizontal well among all preferred wells is selected as the reference well.

4. The horizontal well alignment and correlation method considering formation dip angle according to any one of claims 1-3, characterized in that, A method for straightening the trajectory of a target horizontal well based on the apparent vertical depth and the logging curve of the reference well includes: The curve that best reflects the characteristics of the target layer in the target horizontal well logging curve is selected as the comparison curve. The comparison curve is compared and analyzed with the logging curve of the corresponding reference well. Combined with the apparent vertical depth, the trajectory of the target horizontal well is straightened in segments.

5. A horizontal well alignment and comparison device considering formation dip angle, characterized in that, include: The acquisition unit is used to acquire the measurement-while-drilling information of the target horizontal well, the reference well of the target horizontal well, and the dip angle of the target formation. The measurement-while-drilling information includes at least: well inclination angle and target horizontal well trajectory length; The true vertical depth and horizontal distance determination unit is used to determine the true vertical depth and horizontal distance from the target point of the target horizontal well to the wellhead starting point based on the drilling measurement information, including: the true vertical depth = target horizontal well trajectory length * cos (well inclination angle); the horizontal distance = target horizontal well trajectory length * sin (well inclination angle). The well trajectory straightening unit is used to determine the apparent vertical depth of the target point based on the formation dip angle, true vertical depth, and horizontal distance. This includes: the apparent vertical depth of the starting target point is equal to the true vertical depth of the starting target point; if the formation dip angle of the target point is the same as that of its adjacent previous target point, then: apparent vertical depth of the target point = true vertical depth of the target point + (horizontal distance of the target point - horizontal distance of the adjacent previous target point) * tan(target point formation dip angle) + offset distance of the previous target point; if the formation dip angle of the target point is different from that of its adjacent previous target point, then: apparent vertical depth of the target point = true vertical depth of the target point + (horizontal distance of the target point - horizontal distance of the point where the formation dip angle changes) * tan(target point formation dip angle) + (horizontal distance of the point where the formation dip angle changes - horizontal distance of the previous target point where the formation dip angle changes) * tan(target point formation dip angle of the previous target point) + offset distance of the previous target point where the formation dip angle changes. The formula for calculating the offset distance includes: Offset distance = True vertical depth - Apparent vertical depth; Based on the apparent vertical depth and the logging curve of the reference well, the trajectory of the target horizontal well is straightened. The comparison unit is used to compare the straightened target horizontal well with the reference well, thereby completing the straightening comparison of the target horizontal well.

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