In-situ shale oil well construction method, deviation magnetic guidance system, and multi-wellbore Anti-collision system

Abstract

An in-situ shale oil well construction method, a deviation magnetic guidance system, and a multi-wellbore anti-collision system. The method comprises: on the basis of location information of a shale oil heating area, arranging a ground excitation coil (1) on the ground of a corresponding area, and constructing a magnetic beacon by means of the ground excitation coil (1); constructing horizontal edge wells from both of an upper boundary and a lower boundary of a shale oil reservoir by using geosteering technology, and on the basis of the location information of the shale oil heating area, constructing vertical wells penetrating the shale oil reservoir in the corresponding area; on the basis of the vertical wells, constructing standard horizontal wells by means of a deviation magnetic guidance technique, and on the basis of the standard horizontal wells, using the magnetic beacon as a reference to construct production wells and a plurality of heating wells by means of a dual-horizontal-well magnetic ranging technique, wherein the production wells and the heating wells are three-dimensionally distributed in parallel and do not intersect with each other; and obtaining a well network deployment of unit wells on the basis of the production wells and the heating wells.

Description

In-situ shale oil well construction method, deviation magnetic guidance system and multi-wellbore anti-collision system Technical Field

[0001] The present application relates to the field of oil and gas exploration and production, and in particular to a shale oil in-situ well construction method, a deviation magnetic guidance system, and a multi-wellbore anti-collision system. Background Art

[0002] The underground in-situ mining method is a mining method suitable for shale oil resources buried deep. It refers to the shale oil buried underground. By artificially heating the underground low-maturity shale oil reservoir without mining, the solid kerogen is cracked into oil and gas in situ, and then it is mined using corresponding technology. This development method improves mining efficiency, reduces the occupied area, and reduces the emission of hydrogen sulfide pollutants. It is an efficient, environmentally friendly and economical shale oil development model.

[0003] Current in-situ shale oil extraction technologies suffer from long heating cycles, high heat losses, environmental hazards, and low energy efficiency. Development demands strict control of well spacing and well trajectory error rates, while ensuring adequate underground extraction scale and heating efficiency.

[0004] Conventional measurement while drilling systems, such as continuous inclinometer systems based on geomagnetic guidance and gyroscopic inclinometer systems based on inertial navigation, use measured drill bit inclination and azimuth to calculate the drilling trajectory. These systems have large cumulative errors, poor real-time performance, and cumbersome calculations, making them unable to meet the high-precision guidance requirements of wells with complex structures.

[0005] The anti-collision scanning method in the existing technology is to interpolate the well inclination and azimuth data measured by the inclinometer to obtain the spatial coordinates at a specified well depth, analyze the instrument's error ellipse based on the calibrated instrument error, and calculate the separation coefficient and center distance to analyze the distance between the two wells. However, due to the existence of cumulative errors, the utilization rate is not high for situations where the distance is short and the well depth is long.

[0006] Summary of the Invention

[0007] The present application aims to provide a shale oil in-situ well construction method, a deviation magnetic guidance system, and a multi-wellbore collision prevention system. During the in-situ development of shale oil, magnetic ranging technology is used in conjunction with ground excitation coils to ensure the distance between heating wells, production wells, and observation wells. Geosteering technology is combined with the wellbore trajectory of each type of well to improve drilling accuracy. A heating well, production well, and observation well are combined to form a unit well. Multiple unit wells are then established based on the established development unit well, increasing the number of unit wells and forming a certain scale of underground well factory. This expands the heating area for shale oil, facilitates shale oil extraction, and improves production efficiency.

[0008] To achieve the above-mentioned purpose, the shale oil in-situ well construction method provided in the present application specifically includes: arranging ground excitation coils on the ground of the corresponding area according to the location information of the shale oil heating area, and constructing a magnetic beacon through the ground excitation coils; using geological guidance technology to construct horizontal edge wells at the upper and lower boundaries of the shale oil reservoir, and constructing a vertical well penetrating the shale oil reservoir in the corresponding area according to the location information of the shale oil heating area; constructing a standard horizontal well according to the vertical well through the deviation magnetic guidance technology, and constructing a production well and multiple heating wells according to the standard horizontal well through the dual horizontal well magnetic ranging technology with the magnetic beacon as the benchmark; wherein, the production well and the heating well are distributed in three-dimensional parallel in the formation and do not intersect with each other; and the well network deployment of the unit well is obtained according to the production well and the heating well.

[0009] In the above-mentioned shale oil in-situ well construction method, optionally, constructing a production well and a heating well respectively based on the standard horizontal well through the dual horizontal well magnetic ranging technology with the magnetic beacon as the reference includes: measuring the magnetic field distribution of the magnetic beacon at the measuring point through the magnetic sensor array in the drilling tool to obtain a detection signal, and extracting the amplitude of the detection signal to obtain signal change data; calculating the rate of change of the magnetic field component in the corresponding direction according to the signal change data, and using the three-dimensional Newton gradient descent method to solve the magnetic field size of the AC coil to obtain the position coordinates of the measuring point relative to the magnetic beacon; and controlling the wellbore trajectory of the drilling according to the position coordinates to construct the production well and the heating well.

[0010] In the above-mentioned shale oil in-situ well construction method, optionally, extracting the amplitude of the detection signal to obtain signal change data includes: extracting the amplitude of the detection signal to obtain signal change data through an orthogonal detection algorithm or a matched filtering algorithm.

[0011] In the above-mentioned shale oil in-situ well construction method, optionally, constructing a standard horizontal well based on the vertical well through the deviation magnetic guidance technology includes: calculating the position parameters of the horizontal well using the vertical well as the reference coordinates, adjusting the wellbore trajectory of the standard horizontal well at the preset key node according to the position parameters; and constructing a standard horizontal well according to the wellbore trajectory.

[0012] In the above-mentioned shale oil in-situ well construction method, optionally, calculating the position parameters of the horizontal well using the vertical well as a reference coordinate includes: placing a probe into the vertical well, and calculating the relative position of the horizontal well and the standard vertical well based on the magnetic field signal generated by the probe detected by the magnetic short joint in the horizontal well; and obtaining the position parameters of the horizontal well based on the relative position analysis.

[0013] In the above-mentioned shale oil in-situ well construction method, optionally, multiple heating distributions are located at the intersection of a regular hexagon, and the production well located at the center of the regular hexagon is heated.

[0014] In the above-mentioned shale oil in-situ well construction method, optionally, constructing a production well and multiple heating wells separately according to the standard horizontal well through dual horizontal well magnetic ranging technology with the magnetic beacon as the benchmark also includes: adjusting the wellbore trajectories of the production well and multiple heating wells during the construction process through the rotary steering tool RSS.

[0015] In the above-mentioned shale oil in-situ well construction method, optionally, constructing production wells and multiple heating wells separately according to the standard horizontal well through dual horizontal well magnetic ranging technology with the magnetic beacon as the benchmark also includes: injecting high-frequency electromagnetic waves into the surrounding formations through the linear electrodes of the downhole tool string, so that the metal casing in the adjacent wells gathers downward current and generates a magnetic field signal; obtaining the relative position of the current well and the adjacent well through signal separation calculation based on the electromagnetic signal collected by the probe in the adjacent well; and adjusting the wellbore trajectory of the current well according to the relative position.

[0016] In the above-mentioned shale oil in-situ well construction method, optionally, obtaining the relative position of the current well and the adjacent wells through signal separation calculation based on the electromagnetic signals collected by the probe in the adjacent well includes: performing cluster analysis on the electromagnetic signals to obtain cluster data; constructing a mixing matrix based on the cluster data, and solving linear programming through the mixing matrix to obtain trial calculation data; obtaining multiple source signals through transform domain separation based on the trial calculation data, and performing wavelet transform on the source signals to obtain the relative position of the current well and the adjacent wells.

[0017] The present application also provides a deviated magnetic guidance system suitable for the above-mentioned shale oil in-situ well construction method, the system comprising a measuring probe, a discharge electrode, a magnetic short section and a data acquisition device; the magnetic short section is arranged at the drill bit position of the horizontal well, and is used to generate a magnetic signal; the discharge electrode and the measuring probe are placed into the bottom of the vertical well through a cable; wherein, the discharge electrode is used to discharge into the formation, triggering the drill string in a preset area to generate a magnetic signal; the measuring probe is used to collect magnetic signals in a preset area; the data acquisition device is connected to the measuring probe, and is used to calculate the relative position of the horizontal well and the standard vertical well based on the collected magnetic signals.

[0018] The present application also provides a multi-wellbore anti-collision system suitable for the shale oil in-situ well construction method, the system comprising a probe, an insulating tape, an electromagnetic wave transmitter and a data processing device; the probe is lowered to the bottom of the current well and connected to the electromagnetic wave transmitter through the insulating tape; the electromagnetic wave transmitter is used to inject high-frequency electromagnetic waves into the surrounding formations according to control instructions, so that the metal casing in the adjacent well gathers downward current and generates a magnetic field signal; the probe provides the collected electromagnetic signals of the adjacent wells to the data processing device; the data processing device obtains the relative position of the current well and the adjacent well through signal separation calculation based on the electromagnetic signal.

[0019] The present application also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned method when executing the computer program.

[0020] The present application also provides a computer-readable storage medium, which stores a computer program for executing the above method.

[0021] The present application also provides a computer program product, comprising a computer program / instruction, which implements the steps of the above method when executed by a processor.

[0022] The beneficial technical effects of this application are as follows: (1) Magnetic ranging technology is used to establish a "U"-shaped connection between vertical wells and horizontal wells in shale oil reservoirs, and a deviation magnetic guidance system scheme is designed to improve drilling accuracy. When laying out a horizontal well network, vertical well detection can effectively avoid collisions between horizontal wells, playing a navigation role; (2) The use of magnetic ranging technology in conjunction with ground excitation coils ensures the drilling accuracy of multiple horizontal wells, reduces the possibility of collisions between horizontal wells, and is conducive to the deployment of unit well networks; (3) The ground coils used are portable and easy to lay quickly; and the coil energy intensity can be adjusted according to the depth and complexity of the operation, and has strong adaptability; (4) On the basis of a good deployment of the unit well network, multiple unit wells are established to form an underground factory, which expands the heating scale of the shale oil reservoir and improves the mining efficiency. (5) Through signal separation, multiple adjacent wellbores can be identified simultaneously, thereby improving the drilling efficiency of complex structure wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of the present application, constitute a part of the present application, and do not constitute a limitation of the present application. In the drawings:

[0024] FIG1A is a schematic diagram of a process for an in-situ shale oil well construction method according to an embodiment of the present application;

[0025] FIG1B is a schematic diagram of a shale oil development well construction plant provided in one embodiment of the present application;

[0026] FIG1C is a schematic diagram showing the principle of a ground rectangular coil guidance system provided in one embodiment of the present application;

[0027] FIG2 is a schematic diagram of a production well and a heater well construction process according to an embodiment of the present application;

[0028] FIG3A is a schematic diagram of a construction process of a standard horizontal well provided in one embodiment of the present application;

[0029] FIG3B is a schematic diagram of the construction of a unit well provided in one embodiment of the present application;

[0030] FIG4 is a schematic diagram of a construction process of a production well and multiple heating wells provided in one embodiment of the present application;

[0031] FIG5A is a schematic diagram of a process for obtaining the relative positions of a current well and adjacent wells provided in one embodiment of the present application;

[0032] FIG5B is a schematic diagram of laminar current provided by an embodiment of the present application;

[0033] FIG6 is a schematic structural diagram of a deviated magnetic guidance system provided in one embodiment of the present application;

[0034] FIG7 is a schematic structural diagram of a multi-wellbore anti-collision system provided in one embodiment of the present application;

[0035] FIG8 is a schematic structural diagram of an electronic device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0036] The following will describe in detail the implementation methods of this application in conjunction with the accompanying drawings and examples, so that the application can fully understand how technical means are used to solve technical problems and achieve technical effects, and implement them accordingly. It should be noted that as long as there is no conflict, the various embodiments and the various features in each embodiment of this application can be combined with each other, and the resulting technical solutions are all within the scope of protection of this application.

[0037] Additionally, the steps shown in the flowcharts of the accompanying drawings may 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 may be performed in an order different from that shown.

[0038] Referring to FIG. 1A , the shale oil in-situ well construction method provided in this application specifically includes:

[0039] S101 arranges ground excitation coils on the ground of the corresponding area according to the location information of the shale oil heating area, and constructs a magnetic beacon through the ground excitation coils;

[0040] S102 uses geosteering technology to construct horizontal edge wells at the upper and lower boundaries of the shale oil reservoir, and constructs vertical wells that penetrate the shale oil reservoir in the corresponding area based on the location information of the shale oil heating area;

[0041] S103: constructing a standard horizontal well based on the vertical well by using a deviation magnetic guidance technology, and constructing a production well and multiple heating wells based on the standard horizontal well by using a dual horizontal well magnetic ranging technology with the magnetic beacon as a reference; wherein the production well and the heating well are three-dimensionally distributed in parallel in the formation and do not intersect with each other;

[0042] S104 obtains the well pattern deployment of the unit wells according to the production wells and the heating wells.

[0043] Specifically, as shown in Figure 1B, in actual work, the reservoir range of shale oil can be delineated, and the drilled heating wells and production wells are all located within the reservoir, wherein the shale oil reservoir boundary 1, that is, the interior of the upper and lower boundaries is the low-maturity shale oil zone. At least two edge wells 2 are drilled on the reservoir boundary using geosteering technology. The edge wells are horizontal wells on the reservoir boundary. The geosteering technology can enable the edge wells to reach the reservoir boundary more accurately and control the wellbore trajectory to extend on the reservoir boundary. The edge wells are mainly used to standardize the vertical depths of the heating wells and production wells to prevent them from drilling through the shale oil reservoir and reduce unnecessary engineering losses. In this embodiment, magnetic ranging technology is used to complete the drilling process of various wells, including heating wells, production wells, and observation wells (which can be standard horizontal wells). A unit well network is composed of heating wells, production wells, and observation wells, and multiple unit wells form a large underground factory, which expands the heating range of the shale oil reservoir and improves mining and production efficiency.

[0044] Please refer to Figure 1C again, in which the ground rectangular coil 1 and the ground power supply 2 constitute a magnetic beacon, and the measuring probe 5 and the signal transmission short section 4 in the horizontal well 3 are set on the drill bit 6 to measure the magnetic beacon on the ground, thereby determining the current drill bit position.

[0045] Referring to FIG. 2 , in one embodiment of the present application, constructing a production well and a heating well using the magnetic beacon as a reference based on the standard horizontal well by using the dual horizontal well magnetic ranging technology includes:

[0046] S201 measures the magnetic field distribution of the magnetic beacon at the measuring point by a magnetic sensor array in the drilling tool to obtain a detection signal, and extracts the amplitude of the detection signal to obtain signal change data;

[0047] S202 calculates the rate of change of the magnetic field component in the corresponding direction based on the signal change data, and uses a three-dimensional Newton gradient descent method to solve the magnetic field magnitude of the AC coil to obtain the position coordinates of the measuring point relative to the magnetic beacon;

[0048] S203 controls the wellbore trajectory of the drilling according to the position coordinates to construct the production well and the heating well.

[0049] The step of extracting the amplitude of the detection signal to obtain the signal change data includes: extracting the amplitude of the detection signal to obtain the signal change data by using an orthogonal detection algorithm or a matched filtering algorithm.

[0050] Specifically, in actual operation, the above-mentioned embodiment primarily employs a rectangular conductor deployed on the surface as a magnetic beacon. A magnetic sensor array in the drill string measures the magnetic field distribution at the measuring point. Orthogonal detection and matched filtering algorithms are used to extract the signal amplitude, and the rate of change of the magnetic field components in the corresponding directions is calculated. A three-dimensional Newton gradient descent method is used to determine the magnitude of the AC coil's magnetic field, obtaining the position coordinates of the measuring point relative to the magnetic beacon, ultimately achieving precise control of the wellbore trajectory. Overall, trenchless engineering techniques are employed when drilling the horizontal section of a horizontal well. A rectangular conductor is deployed on the surface as a magnetic beacon. A magnetic sensor array in the drill string measures the magnetic field distribution at the measuring point. Orthogonal detection and matched filtering algorithms are used to extract the signal amplitude, and the rate of change of the magnetic field components in the corresponding directions is calculated. A three-dimensional Newton gradient descent method is used to determine the magnitude of the AC coil's magnetic field and the cross-shaped magnetic target's magnetic field, obtaining the position coordinates of the measuring point relative to the magnetic beacon, ultimately achieving precise control of the wellbore trajectory.

[0051] Referring to FIG. 3A , in one embodiment of the present application, constructing a standard horizontal well using the deviated magnetic guidance technology according to the vertical well includes:

[0052] S301 calculates position parameters of the horizontal well using the vertical well as a reference coordinate, and adjusts the wellbore trajectory of the standard horizontal well at a preset key node according to the position parameters;

[0053] S302 constructs a standard horizontal well according to the wellbore trajectory.

[0054] Specifically, in step S301, calculating the position parameters of the horizontal well using the vertical well as a reference coordinate may include: placing a probe into the vertical well, and calculating the relative position of the horizontal well and the standard vertical well based on the magnetic field signal generated by the probe detected by the magnetic short joint in the horizontal well; and obtaining the position parameters of the horizontal well based on the relative position analysis.

[0055] In practice, before drilling a standard well, vertical wells are drilled every 5 to 6 meters above the horizontal section of the standard well. As shown in Figure 1B, vertical well 3 must vertically penetrate the entire shale oil reservoir to facilitate later formation temperature monitoring. The standard well is a long horizontal well, with the horizontal section located within the shale oil reservoir boundary. A "U"-shaped needle penetration technique is used. When drilling the horizontal section of the standard well, a probe pipe 7 is lowered into the vertical well. The probe pipe 7 is positioned within the vertical well 3. In the standard well, a magnetic sub 8 is connected to the drill bit. Magnetic field signals are used to locate the drill bit, and the relative position of the horizontal well and the vertical well 3 is calculated. Parameters such as the horizontal well's inclination and azimuth are analyzed to control the wellbore's extension according to the designed trajectory. For key points (such as monitoring points, landing points, and target points), "U"-shaped needle penetration magnetic ranging technology is used. Based on a vertical well, a standard well is drilled in the shale oil reservoir, and a probe is placed in the horizontal section of the drilled standard well. On this basis, magnetic ranging technology is used to drill another horizontal well with the standard well as a reference. During the drilling process, magnetic signals are collected and analyzed in real time to calculate the relative positions of the two wells, and then the wellbore trajectory is adjusted in real time to improve drilling accuracy.

[0056] In one embodiment of the present application, the plurality of heaters are distributed at the intersection of a regular hexagon, heating the production well at the center of the regular hexagon. Furthermore, constructing the production well and the plurality of heater wells separately using the standard horizontal well using dual horizontal well magnetic ranging technology with the magnetic beacon as a reference further includes adjusting the wellbore trajectories of the production well and the plurality of heater wells during the construction process using a rotary steerable tool (RSS).

[0057] Specifically, referring to Figures 1B and 3B, a unit well consists of six heater wells and one production well. Formations 101, 102, 103, 104, 105, 106, 107, and 108 are located on different planes. The well pattern is located within a shale oil reservoir, with margin well 2, heater well 4, and production well 5 forming the unit well pattern. After the standard well is drilled, the remaining horizontal wells are drilled using dual-horizontal magnetic ranging technology. During horizontal well drilling, the nearest completed horizontal well is selected as a reference well. A probe is placed in the reference well, and a strong magnetic sub is connected to the drill bit in the active well. Magnetic signals are calculated and analyzed in real time to adjust the wellbore trajectory, thereby improving drilling accuracy and reducing collisions between closely spaced horizontal wells. An optional rotary steerable system (RSS) can be used to address the issue of insufficient control precision in dual-horizontal wells, significantly improving control accuracy. A complete unit well pattern is a regular hexagon. The heating wells are evenly distributed at the intersection of the regular hexagon to heat the entire unit area; the production wells are located at the center of the regular hexagon to produce liquid hydrocarbons converted from kerogen by heating; the heating wells and production wells are distributed in three-dimensional parallel in the formation and do not intersect with each other.

[0058] In summary, the shale oil in-situ well construction method provided in this application mainly includes the following five steps in its implementation process:

[0059] 1. Set up marginal wells at the upper and lower boundaries of the shale oil reservoir;

[0060] 2. Achieve a "U"-shaped connection between standard horizontal wells and vertical wells;

[0061] 3. Use dual horizontal well magnetic ranging technology to drill other horizontal wells, including heater wells and production wells;

[0062] 4. Complete the well pattern deployment of a unit well;

[0063] 5. Deploy multiple unit well networks to build underground factories. (The construction process of multiple unit wells can refer to the above steps 1 to 4)

[0064] Referring to FIG. 4 , in one embodiment of the present application, constructing a production well and multiple heating wells using the magnetic beacon as a reference based on the standard horizontal well through the dual horizontal well magnetic ranging technology further includes:

[0065] S401 injects high-frequency electromagnetic waves into the surrounding formations through the linear electrodes of the downhole tool string, causing the metal casing in the adjacent well to gather downward current and generate magnetic field signals;

[0066] S402: obtaining the relative position of the current well and the adjacent well by signal separation and calculation based on the electromagnetic signal collected by the probe in the adjacent well;

[0067] S403 adjusts the wellbore trajectory of the current well according to the relative position.

[0068] Referring again to FIG5A , the relative positions of the current well and the adjacent well are obtained by signal separation and calculation based on the electromagnetic signals collected by the probes in the adjacent wells, including:

[0069] S501 performs cluster analysis on the electromagnetic signal to obtain cluster data;

[0070] S502 constructs a mixing matrix based on the clustering data, and obtains trial calculation data by solving a linear programming using the mixing matrix;

[0071] S503: A plurality of source signals are obtained by transform domain separation according to the trial calculation data, and the relative positions of the current well and the adjacent wells are obtained by performing wavelet transform on the source signals.

[0072] The above adjustment process is mainly applicable to multi-wellbore collision prevention, and its specific implementation process can include the following steps:

[0073] 1. The ground industrial computer controls the linear electrodes of the downhole tool string to inject high-frequency electromagnetic waves into the surrounding formations;

[0074] 2. Most of the electromagnetic waves are attracted to the metal casing of the adjacent well, where they gather to generate upward and downward currents.

[0075] 3. Use probes to collect the magnetic field and posture generated by the downward current concentrated in the metal casings of multiple adjacent wells;

[0076] 4. Transmit the data to the ground industrial computer through a cable, and the other end of the industrial computer is connected to the computer equipment;

[0077] 5. Execute the signal separation procedure and then simultaneously calculate the distance between the drilling well and the adjacent wells.

[0078] Specifically, the signal separation process in step 5 is as follows: cluster analysis of the mixed signal; estimation of the mixing matrix; trial calculation and solution of the linear programming; separation of multiple source signals in the transform domain; and restoration of multiple source signals through wavelet transform. In actual work, the above process is used as follows:

[0079] The adjacent well casing, linear electrode and current well casing are divided into sufficiently small segments. At this time, these micro segments can be regarded as point current sources, as shown in Figure 5B. Where t is the depth from the point source to the ground, m; h i is the interface depth of the i-th layer, m; σ i is the conductivity of the i-th layer, S / m. The Green's function of the source point of the i-th layer and the field point of the j-th layer is:

[0080] Where j ranges from [1, n], J0(λx) is a zero-order Bessel function, and the following identity exists:

[0081] Combined formula (1) and the boundary conditions of each layer:

[0082] A in formula (1) can be solved ij and B ij :

[0083] Using the prony algorithm, we can find a in formula (4) and formula (5): k 、b k 、c k d k , T is the number of items between 3 and 6.

[0084] According to formula (1), formula (2), formula (4) and formula (5), the Green function is obtained:

[0085] Since the lengths of the adjacent well casings, linear electrodes, and the current well casing are much greater than their own diameters, they can be regarded as one-dimensional linear conductors. Therefore, the potential generated by the current leaking from the casing or linear electrode at any point in the formation can be expressed by the leakage current density ξ (in A / m) as follows:

[0086] The adjacent well casing, linear electrode and current well casing are divided into H section, J section and K section respectively. (unit is V) is the potential generated by the nth micro segment on the mth micro segment, R mn (unit: Ω) is the impedance between the nth micro-segment and the mth micro-segment, I n (unit is A) is the current on the nth micro segment, then the potential of all micro segments gathered on the mth micro segment is:

[0087] And the impedance R mn It can be expressed as:

[0088] When the nth micro-segment and the mth micro-segment are located in the same stratum, formula (6) and formula (9) can be combined to calculate R mn :

[0089] When the nth micro-segment and the mth micro-segment are located in different strata, formula (6) and formula (9) can be combined to calculate R mn :

[0090] Since the resistivity of the casing and the linear electrode is very small, they can be regarded as equipotential bodies, so:

[0091] According to Kirchhoff's current law, the current in the casing and the linear electrode is:

[0092] Among them, I g is the power supply output current, A.

[0093] Combining formula (8), formula (12) and formula (13), the leakage current calculation matrix is ​​established:

[0094] Where b, e, and r represent the adjacent well casing, linear electrode, and current well casing, respectively, and: [I b I e I r ] T =[I1 I2…I (H+J+K) ] T(16) ones(H,1)=[1 1…1] H×1 T (17) ones(1,H)=[1 1…1] 1×H (18) zeros(H,1)=[0 0…0] H×1 T (19) zeros(1,H)=[0 0…0] 1×H (20)

[0095] In addition, the formats of ones(J,1), ones(1,J), zeros(J,1), zeros(1,J), ones(K,1), ones(1,K), zeros(K,1), and zeros(1,K) in formula (14) are consistent with those in formulas (17) to (20).

[0096] By using formula (14), the currents on the adjacent well casing, linear electrode, and current well casing can be calculated as follows:

[0097] Since the linear electrode and the probe are coaxial and very close, the magnetic field signal generated by the linear electrode can be ignored. The electromagnetic signal detected by the probe is the sum of the magnetic induction intensity generated by the current in the casing of the adjacent well and the current well. According to Biot-Savart's law:

[0098] In this way, the relative position of the current well and the adjacent wells can be calculated based on the electromagnetic signals detected by the probe.

[0099] The present application also provides a deviated magnetic guidance system suitable for the above-mentioned shale oil in-situ well construction method, the system comprising a measuring probe, a discharge electrode, a magnetic short section and a data acquisition device; the magnetic short section is arranged at the drill bit position of the horizontal well, and is used to generate a magnetic signal; the discharge electrode and the measuring probe are placed into the bottom of the vertical well through a cable; wherein, the discharge electrode is used to discharge into the formation, triggering the drill string in a preset area to generate a magnetic signal; the measuring probe is used to collect magnetic signals in a preset area; the data acquisition device is connected to the measuring probe, and is used to calculate the relative position of the horizontal well and the standard vertical well based on the collected magnetic signals.

[0100] Please refer to Figure 6 for details. In actual work, the deviated magnetic guidance system consists of a target well 1, a logging cable 2, a discharge electrode 3, a measuring probe 4, a drill bit 5, a magnetic short joint 6, a screw drill 7, a drill string 8, a drilling well 9, a data acquisition system 10, and a power supply 11.

[0101] The logging cable 2, discharge electrode 3, measuring probe 4, data acquisition system 10, and power supply 11 form a passive magnetic guidance system. The measuring probe 4 is located at the bottom of the target well. The discharge electrode 3 discharges into the formation through the logging cable 2 and power supply 11. This current, upon encountering the drill string, generates a magnetic signal, which the measuring probe 4 captures along with the magnetic signal generated by the magnetic sub 6. When the horizontal well drill bit is within 2 meters of the vertical well, the magnetic detection accuracy error can be controlled to within 1%, enabling the closest distance between vertical and horizontal wells to be controlled to the centimeter level. When deploying a horizontal well pattern, vertical well detection can effectively prevent collisions between horizontal wells, providing navigational assistance. Furthermore, a thermos-shaped structure has been added to the measuring probe 4, increasing the temperature resistance of the core measurement system from 125°C to over 200°C.

[0102] The present application also provides a multi-wellbore anti-collision system suitable for the shale oil in-situ well construction method, the system comprising a probe, an insulating tape, an electromagnetic wave transmitter and a data processing device; the probe is lowered to the bottom of the current well and connected to the electromagnetic wave transmitter through the insulating tape; the electromagnetic wave transmitter is used to inject high-frequency electromagnetic waves into the surrounding formations according to control instructions, so that the metal casing in the adjacent well gathers downward current and generates a magnetic field signal; the probe provides the collected electromagnetic signals of the adjacent wells to the data processing device; the data processing device obtains the relative position of the current well and the adjacent well through signal separation calculation based on the electromagnetic signal.

[0103] Please refer to FIG. 7 for details. In actual operation, the multi-wellbore anti-collision system includes a probe 6 , an insulating tape 7 , an electromagnetic wave transmitter 8 , a seven-core cable 9 , an industrial computer 10 and computer equipment 11 .

[0104] Among them, the downhole tool string is as follows from bottom to top: the probe 6 is lowered to the bottom of the drilling well 1, connected to the electromagnetic wave transmitter 8 through the insulating tape 7, and then leads to the seven-core cable 9, and the other end is connected to the industrial computer 10 through the standard interface, and the computer equipment 11 is connected to the industrial computer 10.

[0105] The specific implementation process is as follows: When the active well 1 reaches the collision-avoidance section with adjacent wells 3 and 5, the drill string in the active well 1 is removed, and a downhole tool string connected by a seven-core cable 9 is placed into the active well 1. When operation is required, an industrial computer 10 controls an electromagnetic wave transmitter 8 to inject electromagnetic waves 12 into the surrounding formation. Because the electromagnetic absorption capacity of the metal casing far exceeds that of the formation, the electromagnetic waves 12 converge on the adjacent well metal casings 2 and 4, forming upward and downward currents 13 and 15, thereby generating magnetic field signals 14 and 16. The magnetic field signals 14 and 16 and the position of the adjacent well metal casings 2 and 4, respectively, collected by the probe 6, are transmitted to the industrial computer 10 and computer device 11 via the communication channel of the seven-core cable 9. Computer device 11 then uses the multi-borehole collision-avoidance measurement method of the present invention to determine the relative positions of the active well 1 and adjacent wells 3 and 5. Specifically, computer device 11 can be any device with program computing capabilities, including but not limited to computers, mobile phones, tablet computers, microcomputers, and other intelligent devices.

[0106] The beneficial technical effects of this application are as follows: (1) Magnetic ranging technology is used to establish a "U"-shaped connection between vertical wells and horizontal wells in shale oil reservoirs, and a deviation magnetic guidance system scheme is designed to improve drilling accuracy. When laying out a horizontal well network, vertical well detection can effectively avoid collisions between horizontal wells, playing a navigation role; (2) The use of magnetic ranging technology in conjunction with ground excitation coils ensures the drilling accuracy of multiple horizontal wells, reduces the possibility of collisions between horizontal wells, and is conducive to the deployment of unit well networks; (3) The ground coils used are portable and easy to lay quickly; and the coil energy intensity can be adjusted according to the depth and complexity of the operation, and has strong adaptability; (4) On the basis of a good deployment of the unit well network, multiple unit wells are established to form an underground factory, which expands the heating scale of the shale oil reservoir and improves the mining efficiency. (5) Through signal separation, multiple adjacent wellbores can be identified simultaneously, thereby improving the drilling efficiency of complex structure wells.

[0107] The present application also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned method when executing the computer program.

[0108] The present application also provides a computer-readable storage medium, which stores a computer program for executing the above method.

[0109] The present application also provides a computer program product, comprising a computer program / instruction, which implements the steps of the above method when executed by a processor.

[0110] As shown in FIG8 , the electronic device 600 may further include: a communication module 110, an input unit 120, an audio processor 130, a display 160, and a power supply 170. It is worth noting that the electronic device 600 does not necessarily include all of the components shown in FIG8 ; furthermore, the electronic device 600 may also include components not shown in FIG8 , for which reference may be made to the prior art.

[0111] As shown in FIG8 , the central processing unit 100 is sometimes also referred to as a controller or an operation control unit, and may include a microprocessor or other processor devices and / or logic devices. The central processing unit 100 receives inputs and controls the operations of various components of the electronic device 600 .

[0112] Memory 140 may be, for example, one or more of a cache, flash memory, hard drive, removable media, volatile memory, non-volatile memory, or other suitable devices. It may store the aforementioned failure-related information and may also store programs that execute the relevant information. The CPU 100 may execute the programs stored in memory 140 to implement information storage or processing.

[0113] The input unit 120 provides input to the CPU 100. The input unit 120 may be, for example, a keypad or touch input device. The power supply 170 is used to provide power to the electronic device 600. The display 160 is used to display objects such as images and text. The display may be, for example, an LCD display, but is not limited thereto.

[0114] The memory 140 may be a solid-state memory, such as a read-only memory (ROM), a random access memory (RAM), or a SIM card. Alternatively, it may be a memory that retains information even when power is off, can be selectively erased, and is provided with more data. Examples of such memory are sometimes referred to as EPROMs. The memory 140 may also be some other type of device. The memory 140 includes a buffer memory 141 (sometimes referred to as a buffer). The memory 140 may include an application / function storage unit 142 for storing application programs and function programs or processes for executing the operations of the electronic device 600 via the central processing unit 100.

[0115] The memory 140 may also include a data storage unit (data 143) for storing data, such as contacts, digital data, pictures, sounds, and / or any other data used by the electronic device. The driver storage unit (driver 144) of the memory 140 may include various driver programs for communication functions of the electronic device and / or for executing other functions of the electronic device (such as messaging applications, address book applications, etc.).

[0116] The communication module 110 is a transmitter / receiver 110 that transmits and receives signals via an antenna 111. The communication module (transmitter / receiver) 110 is coupled to the central processor 100 to provide input signals and receive output signals, which may be the same as in a conventional mobile communication terminal.

[0117] Multiple communication modules 110, such as cellular network modules, Bluetooth modules, and / or wireless local area network modules, can be provided in the same electronic device based on different communication technologies. The communication module (transmitter / receiver) 110 is also coupled to a speaker 131 and a microphone 132 via an audio processor 130 to provide audio output via the speaker 131 and receive audio input from the microphone 132, thereby implementing common telecommunication functions. The audio processor 130 may include any suitable buffer, decoder, amplifier, etc. Furthermore, the audio processor 130 is coupled to the central processing unit 100, enabling local recording via the microphone 132 and playback of stored audio via the speaker 131.

[0118] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0119] The present application is described with reference to the flow chart and / or block diagram of the method, device (system), and computer program product according to the embodiment of the present application. It should be understood that each flow process and / or box in the flow chart and / or block diagram and the combination of the flow process and / or box in the flow chart and / or block diagram can be realized by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processing machine or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for realizing the function specified in one flow chart flow or multiple flows and / or one box or multiple boxes of the block diagram.

[0120] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0121] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0122] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A shale oil in-situ well construction method, characterized in that: The method comprises: Arrange a ground excitation coil on the ground of the corresponding area according to the location information of the shale oil heating area, and construct a magnetic beacon through the ground excitation coil; Use geosteering technology to construct horizontal edge wells at the upper and lower boundaries of the shale oil reservoir, and construct vertical wells that penetrate the shale oil reservoir in the corresponding area based on the location information of the shale oil heating area; According to the vertical well, a standard horizontal well is constructed by deviating from the magnetic guidance technology, and according to the standard horizontal well, a production well and a plurality of heating wells are respectively constructed by using the double horizontal well magnetic ranging technology with the magnetic beacon as a reference; wherein the production well and the heating well are three-dimensionally distributed in parallel in the formation and do not intersect each other; The well network deployment of the unit wells is obtained based on the production wells and the heating wells.

2. The shale oil in-situ well construction method according to claim 1, characterized in that: According to the standard horizontal well, the production well and the heating well are constructed by using the dual horizontal well magnetic ranging technology with the magnetic beacon as the reference, including: The magnetic field distribution of the magnetic beacon at the measuring point is measured by the magnetic sensor array in the drilling tool to obtain a detection signal, and the amplitude of the detection signal is extracted to obtain signal change data; Calculating the rate of change of the magnetic field component in the corresponding direction according to the signal change data, and using the three-dimensional Newton gradient descent method to solve the magnetic field size of the AC coil to obtain the position coordinates of the measuring point relative to the magnetic beacon; The production well and the heating well are constructed by controlling the wellbore trajectory of the drilling according to the position coordinates.

3. The shale oil in-situ well construction method according to claim 2, characterized in that: Extracting the amplitude of the detection signal to obtain signal change data includes: extracting the amplitude of the detection signal to obtain signal change data by using an orthogonal detection algorithm or a matched filtering algorithm.

4. The shale oil in-situ well construction method according to claim 2, characterized in that: According to the vertical well, constructing a standard horizontal well by using the deviation magnetic guidance technology includes: Calculate the position parameters of the horizontal well by using the vertical well as a reference coordinate, and adjust the wellbore trajectory of the standard horizontal well at a preset key node according to the position parameters; A standard horizontal well is constructed according to the wellbore trajectory.

5. The shale oil in-situ well construction method according to claim 4, characterized in that: Calculating the position parameters of the horizontal well by using the vertical well as the reference coordinates includes: A probe is placed in the vertical well, and the relative position of the horizontal well and the standard vertical well is calculated based on the magnetic field signal generated by the probe when the magnetic short section in the horizontal well detects the magnetic field; The position parameters of the horizontal well are obtained according to the relative position analysis.

6. The shale oil in-situ well construction method according to claim 1, characterized in that: Multiple heaters are distributed at the intersections of a regular hexagon, and the production well located at the center of the regular hexagon is heated.

7. The shale oil in-situ well construction method according to claim 1, characterized in that: According to the standard horizontal well, the production well and multiple heating wells are constructed separately by using the dual horizontal well magnetic ranging technology with the magnetic beacon as the reference, which also includes: adjusting the wellbore trajectories of the production well and multiple heating wells during the construction process by using the rotary steering tool RSS.

8. The shale oil in-situ well construction method according to claim 1, characterized in that: According to the standard horizontal well, the production well and the multiple heating wells are constructed by using the dual horizontal well magnetic ranging technology with the magnetic beacon as the reference, and the following further comprises: High-frequency electromagnetic waves are injected into the surrounding formations through the linear electrodes of the downhole tool string, causing the metal casing in the adjacent well to gather downward current and generate magnetic field signals; The relative position of the current well and the adjacent well is obtained by signal separation and calculation based on the electromagnetic signal collected by the probe in the adjacent well; The wellbore trajectory of the current well is adjusted according to the relative position.

9. The shale oil in-situ well construction method according to claim 8, characterized in that: The relative position of the current well and the adjacent well is obtained by signal separation and calculation based on the electromagnetic signal collected by the probe in the adjacent well, including: Performing cluster analysis on the electromagnetic signal to obtain cluster data; Constructing a mixing matrix according to the clustering data, and solving a linear programming through the mixing matrix to obtain trial calculation data; According to the trial calculation data, multiple source signals are obtained through transform domain separation, and the source signals are subjected to wavelet transform to obtain the relative position of the current well and the adjacent wells.

10. A deviated magnetic guidance system suitable for the shale oil in-situ well construction method according to any one of claims 1 to 9, characterized in that: The system comprises a measuring probe, a discharge electrode, a magnetic short section and a data acquisition device; The magnetic sub is arranged at the drill bit position of the horizontal well to generate a magnetic signal; The discharge electrode and the measuring probe are placed into the bottom of the vertical well through cables; The discharge electrode is used to discharge to the formation, triggering the drill string in the preset area to generate magnetic signals; the measuring probe is used to collect magnetic signals in the preset area; The data acquisition device is connected to the measuring probe and is used to calculate the relative position of the horizontal well and the standard vertical well according to the acquired magnetic signals.

11. A multi-wellbore anti-collision system applicable to the shale oil in-situ well construction method according to any one of claims 1 to 9, characterized in that: The system comprises a probe, an insulating tape, an electromagnetic wave transmitter and a data processing device; The probe is lowered to the bottom of the current well and connected to the electromagnetic wave transmitter via the insulating tape; The electromagnetic wave transmitter is used to inject high-frequency electromagnetic waves into the surrounding formations according to control instructions, so that the metal casing in the adjacent well gathers downward current and generates a magnetic field signal; The probe provides the electromagnetic signals collected from the adjacent wells to the data processing device; The data processing device obtains the relative position of the current well and the adjacent wells through signal separation calculation based on the electromagnetic signal.

12. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 9 is implemented.

13. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program for causing a computer to execute the method according to any one of claims 1 to 9.

14. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the steps of the method according to any one of claims 1 to 9 are implemented.

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