While-drilling seismic wave forepoling device and method, operation method and measurement equipment

Abstract

The invention provides a while-drilling seismic wave forepoling device and method, an operation method and measurement equipment. A while-drilling seismic wave forepoling device comprises a plurality of sensors, a drill collar body, a main control unit and a plurality of vibroseis assemblies, and the sensors, the main control unit and the vibroseis assemblies are all installed on the outer wall of the drill collar body. The plurality of sensors and the plurality of vibroseis assemblies are connected with the main control unit.

Description

Technical Field

[0001] The present invention relates to the technical field of while-drilling measurement, and in particular to a while-drilling seismic wavefront detection device, method, operation method and measurement equipment. Background Art

[0002] During drilling operations, when the drill bit encounters complex geology, it is easy to cause risks such as blowouts and formation collapse, which seriously threatens drilling safety. As commonly used exploration technologies, seismic while drilling and electromagnetic wave resistivity prospecting while drilling play an important role in the drilling process. However, with the increase in drilling depth and complexity, the geological conditions faced during drilling are becoming increasingly complex, and the difficulty of exploration while drilling is also increasing.

[0003] Under extremely complex geological conditions, the traditional exploration while drilling method has certain limitations in drilling operations, including:

[0004] (1) Traditional drill bit seismic while drilling has problems such as weak PDC (polycrystalline diamond compact bit) seismic energy, unstable signal characteristics, and limited propagation distance. It is difficult to meet the needs of long-distance advance detection of geological structures ahead of the drill bit under complex geological conditions. Although the vertical seismic profiling (VSP) while drilling technology is an artificial excitation source, the long distance between the excitation point and the detector makes the long-distance effective reflection signal weak and the forward exploration resolution low.

[0005] (2) Traditional electromagnetic wave resistivity forward-looking technology detects the geological structure ahead through resistivity inversion, but its application in complex geological conditions has certain limitations. Electromagnetic waves attenuate quickly in the strata, making it difficult to effectively detect deep geological structures. In addition, electromagnetic wave resistivity forward-looking technology is easily affected by magnetic interference from the downhole strata and tools in the drilling environment, resulting in a low signal-to-noise ratio, which affects the detection accuracy and reliability.

[0006] (3) The forward-looking seismic and electromagnetic wave resistivity technologies cannot control the excitation signal in the axial direction. The effective energy in the front detection area accounts for a small proportion, and the forward detection effect is not ideal. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a seismic wavefront detection device, method, operation method and measurement equipment while drilling in view of the deficiencies in the prior art.

[0008] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a seismic wavefront detection device while drilling, comprising: multiple sensors, a drill collar body, a main control unit, and multiple controllable seismic source assemblies, wherein the multiple sensors, the main control unit, and the multiple controllable seismic source assemblies are all installed on the outer wall of the drill collar body, and the multiple sensors and the multiple controllable seismic source assemblies are all connected to the main control unit.

[0009] The beneficial effects of the technical solution of the present invention are: by optimizing the downhole source arrangement and signal acquisition technology, high-precision beam forming and seismic signal acquisition are achieved. The detection of geological bodies ahead of the drill bit improves the signal-to-noise ratio of the forward seismic reflection wave and increases the forward exploration accuracy by beam focusing, making up for the shortcomings of the traditional forward exploration method while drilling. The seismic signal is excited by the controllable source assembly close to the well wall, and the continuous excitation energy accumulation and controllable seismic signal characteristics are utilized to improve the detection ability of long-distance weak reflection signals without damaging the well wall. The space on both sides of the drill collar is fully utilized, and multiple controllable source assemblies and multiple sensors are arranged along the drilling axis direction at positions close to the well wall on both sides of the drill collar, which greatly enriches the arrangement, excitation and reception of the source during the drilling process. By utilizing the multiple controllable sources arranged on both sides of the drill collar and their high-precision signal control characteristics, the forward propagation of seismic waves can be enhanced by focusing, and more accurate geological structure imaging results can be obtained through reverse time migration imaging. The space on both sides of the main control unit on the drill collar body in the axial direction is relatively large, and multiple working controllable vibrator components can be placed, so that the beam forming method can be realized.

[0010] Furthermore, the controllable seismic source assembly includes: a counterweight shell, a telescopic push rod, and a base, wherein the base is installed on the outer wall of the drill collar body, one end of the telescopic push rod is connected to the base, and the counterweight shell is installed on the other end of the telescopic push rod.

[0011] The beneficial effect of adopting the above further technical solution is that the telescopic top rod of the controllable vibrator assembly is extended, so that the controllable vibrator assembly can be close to the well wall, so that the energy of the vibrator can be radiated to the formation to the maximum extent when the vibrator is working. After the controllable vibrator assembly is started, the moving coil inside the vibrator controls the counterweight shell to vibrate, thereby stimulating seismic signals.

[0012] Furthermore, the telescopic top rod is an electric telescopic rod, a hydraulic telescopic rod or a pneumatic telescopic rod, and the telescopic top rod is a hollow support frame structure or a solid support plate structure.

[0013] The beneficial effects of adopting the above further technical solution are: the hollow support frame can save costs, the solid support plate has higher stability, and it is convenient to select telescopic top rods of different structures and forms according to specific needs.

[0014] Furthermore, multiple sensors are symmetrically arranged along the central axis of the drill shank body, multiple controllable seismic source assemblies are arranged adjacent to the drill bit, multiple sensors are located between the controllable seismic source assembly and the drill bit, multiple controllable seismic source assemblies are located on both sides of the main control unit, and multiple controllable seismic source assemblies located on both sides of the main control unit are symmetrically arranged along the central axis of the drill shank body; the sensor is a three-component sensor, and the controllable seismic source assembly is an electromagnetic controllable seismic source assembly.

[0015] The beneficial effect of adopting the above further technical solution is: make full use of the space on both sides of the drill collar, arrange multiple controllable source components and multiple sensors along the drilling axis at positions close to the well wall on both sides of the drill collar, which greatly enriches the arrangement, excitation and reception of the source during the drilling process. By utilizing the multiple controllable sources arranged on both sides of the drill collar and their high-precision signal control characteristics, it is possible to achieve the focus enhancement of the forward propagation of seismic waves, and obtain more accurate geological structure imaging results through reverse time migration imaging. The space on both sides of the main control unit on the drill collar body in the axial direction is relatively large, and multiple working controllable source components can be placed, so that the beam forming method can be realized.

[0016] In addition, the present invention also provides a while-drilling measurement equipment, comprising any one of the above-mentioned while-drilling seismic wavefront detection devices.

[0017] The beneficial effects of the technical solution of the present invention are: by optimizing the downhole source arrangement and signal acquisition technology, high-precision beam forming and seismic signal acquisition are achieved. The detection of geological bodies ahead of the drill bit improves the signal-to-noise ratio of the forward seismic reflection wave and increases the forward exploration accuracy by beam focusing, making up for the shortcomings of the traditional forward exploration method while drilling. The seismic signal is excited by the controllable source assembly close to the well wall, and the continuous excitation energy accumulation and controllable seismic signal characteristics are utilized to improve the detection ability of long-distance weak reflection signals without damaging the well wall. The space on both sides of the drill collar is fully utilized, and multiple controllable source assemblies and multiple sensors are arranged along the drilling axis direction at positions close to the well wall on both sides of the drill collar, which greatly enriches the arrangement, excitation and reception of the source during the drilling process. By utilizing the multiple controllable sources arranged on both sides of the drill collar and their high-precision signal control characteristics, the forward propagation of seismic waves can be enhanced by focusing, and more accurate geological structure imaging results can be obtained through reverse time migration imaging. The space on both sides of the main control unit on the drill collar body in the axial direction is relatively large, and multiple working controllable vibrator components can be placed, so that the beam forming method can be realized.

[0018] In addition, the present invention also provides an operating method for a while-drilling seismic wavefront detection device, which is based on a while-drilling seismic wavefront detection device described in any one of the above items, and the operating method for the while-drilling seismic wavefront detection device includes: S1. When starting detection, start the telescopic function of the controllable seismic source assembly until the controllable seismic source assembly abuts against the well wall; S2. Configure the time-frequency information and output power of the controllable seismic source assembly, start the vibration function of the controllable seismic source assembly, and stimulate seismic signals.

[0019] The beneficial effects of the technical solution of the present invention are: setting the time-frequency information and source energy output information of the controllable vibrator assembly, ensuring that the time-frequency information of the seismic record is known and accurately controlling the delayed emission of multiple controllable vibrator assemblies. By exciting the seismic signal by the controllable vibrator assembly close to the well wall, the continuous excitation energy accumulation and the controllable seismic signal characteristics are utilized to improve the detection capability of the long-distance weak reflection signal without damaging the well wall.

[0020] Furthermore, in step S1, the telescopic function of the controllable seismic source assembly is started, and the telescopic top rod of the controllable seismic source assembly is extended until the counterweight shell at the other end of the telescopic top rod abuts against the well wall; in step S2, the main control unit is provided with time-frequency information and output power of the controllable seismic source assembly, and the vibration function of the controllable seismic source assembly is started, and the moving coil inside the controllable seismic source assembly controls the counterweight shell to vibrate, thereby stimulating seismic signals.

[0021] The beneficial effect of adopting the above further technical solution is that the telescopic push rod of the controllable vibrator assembly is extended, so that the controllable vibrator assembly can be close to the well wall. After the controllable vibrator assembly is started, the moving coil inside the vibrator controls the counterweight shell to vibrate, thereby stimulating seismic signals. When the detection starts, the controllable vibrator assemblies on both sides of the drill collar body are started, and the telescopic push rod of the controllable vibrator assembly is extended and contacts the well wall, and then the telescopic push rod continues to pressurize so that the counterweight shell can be pressed against the well wall, so that the energy of the vibrator is radiated to the formation to the maximum extent when the vibrator is working.

[0022] Again, the present invention also provides a method for drilling seismic wavefront detection, which is based on a drilling seismic wavefront detection device described in any one of the above items, and the method comprises: S1, synthesizing the wavefront excited by each seismic source in the form of a spherical wave into a beam surface through delayed excitation of each controllable seismic source component; S2, receiving seismic records through sensors, processing the controllable seismic source seismic data by cross-correlation, analyzing and obtaining the wave velocity of the direct wave, and creating an initial geological velocity model based on the wave velocity result; S3, cutting off the direct wave in the interference seismic record; S4, exciting the seismic record at the source position of the initial geological velocity model to obtain a forward wave field; applying the interference seismic record that actually obtains and cuts off the direct wave in reverse time at the sensor position to obtain a reverse wave field; S5, correlating and superimposing the forward wave field and the reverse wave field to obtain a reverse time migration imaging result based on beamforming.

[0023] The beneficial effect of the technical solution of the present invention is that the propagation angle of the beam surface can be adjusted by different delay settings, and the propagation angle of the beam surface is adjusted according to the forward exploration requirements. By utilizing the multiple controllable seismic sources arranged on both sides of the drill collar and their high-precision signal control characteristics, the forward propagation of seismic waves can be enhanced, and more accurate geological structure imaging results can be obtained through reverse time migration imaging.

[0024] Furthermore, in step S1, the propagation angle of the wavefront is adjusted by different delay settings; wherein the propagation angle of the beam surface is adjusted according to the forward exploration requirements; in step S2, after the velocity of the direct wave is obtained, the velocity value is assigned to the formation to create an initial geological velocity model based on the velocity result.

[0025] The beneficial effect of adopting the above further technical solution is that the propagation angle of the beam surface can be adjusted by different delay settings, and the propagation angle of the beam surface is adjusted according to the forward exploration requirements. By utilizing the multiple controllable seismic sources arranged on both sides of the drill collar and their high-precision signal control characteristics, the forward propagation of seismic waves can be enhanced, and more accurate geological structure imaging results can be obtained through reverse time migration imaging.

[0026] Furthermore, in step S1, when the forward propagation angle is θ, the excitation delay calculation formula between the vibrator components is: Wherein, t1 is the delayed excitation time of the current vibrator assembly relative to the previous vibrator assembly, x1 is the focal distance, v1 is the surrounding rock velocity, and θ is the beam propagation angle; in step S2, the initial geological velocity model is created based on the velocity result by: creating a matrix, the grid size set in the length, width and height directions of the matrix is ​​consistent with the actual stratum, the numerical value in the matrix represents the stratum velocity, and the velocity is the direct wave velocity; the calculation formula of the interferometric seismic record generated by the cross-correlation in the cross-correlation of the vibrator seismic data is: Among them, f(t) is the seismic record, g(t) is the sensor record, t is the integration variable used for full-time integration, τ represents the time delay, and R(t) is the interference seismic record generated by cross-correlation; the calculation formula for the direct wave velocity calculated by the slope of the direct wave component in the seismic record is: v2=x2 / t2, among which v2 is the wave velocity, x2 is the sensor arrangement length, and t2 is the delayed excitation time of the current controllable source assembly relative to the previous controllable source assembly.

[0027] The beneficial effect of adopting the above further technical solution is that the propagation angle of the beam surface can be adjusted by different delay settings, and the propagation angle of the beam surface is adjusted according to the forward exploration requirements. By utilizing the multiple controllable seismic sources arranged on both sides of the drill collar and their high-precision signal control characteristics, the forward propagation of seismic waves can be enhanced, and more accurate geological structure imaging results can be obtained through reverse time migration imaging.

[0028] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic structural diagram of a while-drilling seismic wavefront detection device provided in an embodiment of the present invention.

[0030] Figure 2 A schematic diagram of the operation of a while-drilling seismic wavefront detection device provided in an embodiment of the present invention.

[0031] Figure 3 A schematic diagram of a beamforming method provided by an embodiment of the present invention.

[0032] Figure 4 A schematic diagram of obtaining the wave velocity of a direct wave provided in an embodiment of the present invention.

[0033] Figure 5 A schematic flowchart of an operation method of a while-drilling seismic wavefront detection device provided in an embodiment of the present invention.

[0034] Figure 6 A schematic flowchart of a seismic wavefront detection while drilling method provided in an embodiment of the present invention.

[0035] Explanation of the accompanying drawings: 1. three-component sensor; 2. drill collar body; 3. main control unit; 4. electromagnetic controllable vibrator assembly; 5. well wall; 6. counterweight shell; 7. telescopic push rod; 8. base; 9. wave front; 10. beam surface. DETAILED DESCRIPTION

[0036] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention but not to limit the scope of the present invention.

[0037] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a seismic wavefront detection device while drilling, comprising: a plurality of sensors, a drill collar body 2, a main control unit 3, and a plurality of controllable seismic source assemblies, wherein the plurality of sensors, the main control unit 3, and the plurality of controllable seismic source assemblies are all installed on the outer wall of the drill collar body 2, and the plurality of sensors and the plurality of controllable seismic source assemblies are all connected to the main control unit 3.

[0038] The beneficial effects of the technical solution of the present invention are: by optimizing the downhole source arrangement and signal acquisition technology, high-precision beam forming and seismic signal acquisition are achieved. The detection of geological bodies ahead of the drill bit improves the signal-to-noise ratio of the forward seismic reflection wave and increases the forward exploration accuracy by beam focusing, making up for the shortcomings of the traditional forward exploration method while drilling. The seismic signal is excited by the controllable source assembly close to the well wall, and the continuous excitation energy accumulation and controllable seismic signal characteristics are utilized to improve the detection ability of long-distance weak reflection signals without damaging the well wall. The space on both sides of the drill collar is fully utilized, and multiple controllable source assemblies and multiple sensors are arranged along the drilling axis direction at positions close to the well wall on both sides of the drill collar, which greatly enriches the arrangement, excitation and reception of the source during the drilling process. By utilizing the multiple controllable sources arranged on both sides of the drill collar and their high-precision signal control characteristics, the forward propagation of seismic waves can be enhanced by focusing, and more accurate geological structure imaging results can be obtained through reverse time migration imaging. The space on both sides of the main control unit on the drill collar body in the axial direction is relatively large, and multiple working controllable vibrator components can be placed, so that the beam forming method can be realized.

[0039] The embodiment of the present invention provides a seismic wave forward exploration device while drilling, which can be a downhole controllable vibrator seismic wave forward exploration device while drilling, and realizes high-precision beam forming and seismic signal acquisition by optimizing downhole source arrangement and signal acquisition technology. The geological body detection ahead of the drill bit improves the signal-to-noise ratio of the forward exploration seismic reflection wave and increases the forward exploration accuracy by beam focusing, which makes up for the shortcomings of the traditional forward exploration method while drilling.

[0040] like Figure 1 and Figure 2 As shown, further, the controllable seismic source assembly includes: a counterweight shell 6, a telescopic push rod 7, and a base 8, wherein the base 8 is installed on the outer wall of the drill collar body 2, one end of the telescopic push rod 7 is connected to the base 8, and the counterweight shell 6 is installed on the other end of the telescopic push rod 7.

[0041] The beneficial effect of adopting the above further technical solution is that the telescopic top rod of the controllable vibrator assembly is extended, so that the controllable vibrator assembly can be close to the well wall, so that the energy of the vibrator can be radiated to the formation to the maximum extent when the vibrator is working. After the controllable vibrator assembly is started, the moving coil inside the vibrator controls the counterweight shell to vibrate, thereby stimulating seismic signals.

[0042] like Figure 1 and Figure 2 As shown, further, the telescopic top rod 7 is an electric telescopic rod, a hydraulic telescopic rod or a pneumatic telescopic rod, and the telescopic top rod 7 is a hollow support frame structure or a solid support plate structure.

[0043] The beneficial effects of adopting the above further technical solution are: the hollow support frame can save costs, the solid support plate has higher stability, and it is convenient to select telescopic top rods of different structures and forms according to specific needs.

[0044] like Figure 1 and Figure 2 As shown, further, multiple sensors are symmetrically arranged along the central axis of the drill shank body 2, multiple controllable seismic source components are arranged adjacent to the drill bit, multiple sensors are located between the controllable seismic source components and the drill bit, multiple controllable seismic source components are located on both sides of the main control unit 3, and multiple controllable seismic source components located on both sides of the main control unit 3 are symmetrically arranged along the central axis of the drill shank body 2; the sensor is a three-component sensor 1, and the controllable seismic source component is an electromagnetic controllable seismic source component 4.

[0045] The beneficial effect of adopting the above further technical solution is: make full use of the space on both sides of the drill collar, arrange multiple controllable source components and multiple sensors along the drilling axis at positions close to the well wall on both sides of the drill collar, which greatly enriches the arrangement, excitation and reception of the source during the drilling process. By utilizing the multiple controllable sources arranged on both sides of the drill collar and their high-precision signal control characteristics, it is possible to achieve the focus enhancement of the forward propagation of seismic waves, and obtain more accurate geological structure imaging results through reverse time migration imaging. The space on both sides of the main control unit on the drill collar body in the axial direction is relatively large, and multiple working controllable source components can be placed, so that the beam forming method can be realized.

[0046] Embodiment 1:

[0047] like Figure 1 and Figure 2 As shown, embodiment 1 of the present invention provides a downhole controllable seismic source while drilling seismic wavefront detection device (seismic wavefront detection device while drilling), comprising: electromagnetic controllable seismic source components 4 arranged on both sides of a drill collar body 2 (taking one on each side as an example), and the electromagnetic controllable seismic source components are arranged near the drill bit.

[0048] The electromagnetic controllable vibrator assembly 4 includes: a counterweight housing 6, a telescopic mandrel 7, and a base 8. The telescopic mandrel 7 is fixed to the side of the counterweight housing 6 facing the well wall 5. The counterweight housing 6 is fixedly connected to the base 8 through the telescopic mandrel 7, and the base 8 is used to connect to the drill collar body 2. The counterweight housing is fixed to the telescopic mandrel, and the base is fixedly integrated on the drill collar body.

[0049] The telescopic top rod 7 in this embodiment can be an electric telescopic rod, or a hydraulic or pneumatic controlled telescopic rod. Those skilled in the art can choose according to the specific situation, which will not be described in detail here.

[0050] In this embodiment, the telescopic top rod 7 structure can be a hollow support frame (which can save costs) or a solid support plate (with higher stability). Those skilled in the art can choose according to specific needs, which will not be described in detail here.

[0051] In this embodiment, it also includes: a three-component sensor 1 arranged on the well wall between the drill bit and the electromagnetic controllable vibrator assembly 4.

[0052] In this embodiment, the three-component sensors 1 on both sides of the drill collar body 2 are symmetrically arranged at appropriate intervals along the central axis of the drill collar body 2. At least one electromagnetic vibrator assembly is arranged on each side of the drill collar (drill collar body), and the electromagnetic vibrator assemblies on both sides are symmetrically arranged along the central axis of the drill collar body.

[0053] It can be understood that in some other implementations, a plurality of electromagnetic controllable vibrator assemblies 4 are arranged on each side of the main control unit 3 , and the electromagnetic controllable vibrator assemblies 4 on both sides are symmetrically arranged along the central axis of the drill collar body 2 .

[0054] In this embodiment, the main control unit 3 is fixed on the drill collar body 2 , and the electromagnetic controllable vibrator components 4 are located on both sides of the main control unit 3 .

[0055] In addition, the present invention also provides a while-drilling measurement equipment, comprising any one of the above-mentioned while-drilling seismic wavefront detection devices.

[0056] The beneficial effects of the technical solution of the present invention are: by optimizing the downhole source arrangement and signal acquisition technology, high-precision beam forming and seismic signal acquisition are achieved. The detection of geological bodies ahead of the drill bit improves the signal-to-noise ratio of the forward seismic reflection wave and increases the forward exploration accuracy by beam focusing, making up for the shortcomings of the traditional forward exploration method while drilling. The seismic signal is excited by the controllable source assembly close to the well wall, and the continuous excitation energy accumulation and controllable seismic signal characteristics are utilized to improve the detection ability of long-distance weak reflection signals without damaging the well wall. The space on both sides of the drill collar is fully utilized, and multiple controllable source assemblies and multiple sensors are arranged along the drilling axis direction at positions close to the well wall on both sides of the drill collar, which greatly enriches the arrangement, excitation and reception of the source during the drilling process. By utilizing the multiple controllable sources arranged on both sides of the drill collar and their high-precision signal control characteristics, the forward propagation of seismic waves can be enhanced by focusing, and more accurate geological structure imaging results can be obtained through reverse time migration imaging. The space on both sides of the main control unit on the drill collar body in the axial direction is relatively large, and multiple working controllable vibrator components can be placed, so that the beam forming method can be realized.

[0057] The embodiment of the present invention provides a measurement while drilling device, including the downhole controllable vibrator while drilling seismic wavefront detection device (seismic wavefront detection device while drilling) described in Embodiment 1 of the present invention.

[0058] like Figure 5 As shown, in addition, the present invention also provides an operating method for a while-drilling seismic wavefront detection device, which is a while-drilling seismic wavefront detection device based on any one of the above-mentioned devices, and the operating method for the while-drilling seismic wavefront detection device includes: S1, when starting detection, starting the telescopic function of the controllable seismic source assembly until the controllable seismic source assembly abuts against the well wall; S2, configuring the time-frequency information and output power of the controllable seismic source assembly, starting the vibration function of the controllable seismic source assembly, and stimulating seismic signals.

[0059] The beneficial effects of the technical solution of the present invention are: setting the time-frequency information and source energy output information of the controllable vibrator assembly, ensuring that the time-frequency information of the seismic record is known and accurately controlling the delayed emission of multiple controllable vibrator assemblies. By exciting the seismic signal by the controllable vibrator assembly close to the well wall, the continuous excitation energy accumulation and the controllable seismic signal characteristics are utilized to improve the detection capability of the long-distance weak reflection signal without damaging the well wall.

[0060] Furthermore, in step S1, the telescopic function of the controllable seismic source assembly is started, and the telescopic top rod of the controllable seismic source assembly is extended until the counterweight shell at the other end of the telescopic top rod abuts against the well wall; in step S2, the main control unit is provided with time-frequency information and output power of the controllable seismic source assembly, and the vibration function of the controllable seismic source assembly is started, and the moving coil inside the controllable seismic source assembly controls the counterweight shell to vibrate, thereby stimulating seismic signals.

[0061] The beneficial effect of adopting the above further technical solution is that the telescopic push rod of the controllable vibrator assembly is extended, so that the controllable vibrator assembly can be close to the well wall. After the controllable vibrator assembly is started, the moving coil inside the vibrator controls the counterweight shell to vibrate, thereby stimulating seismic signals. When the detection starts, the controllable vibrator assemblies on both sides of the drill collar body are started, and the telescopic push rod of the controllable vibrator assembly is extended and contacts the well wall, and then the telescopic push rod continues to pressurize so that the counterweight shell can be pressed against the well wall, so that the energy of the vibrator is radiated to the formation to the maximum extent when the vibrator is working.

[0062] Embodiment 2:

[0063] Embodiment 2 of the present invention provides a working method of the downhole vibroseis seismic wavefront detection device while drilling (operating method of the seismic wavefront detection device while drilling) described in Embodiment 1, comprising the following steps:

[0064] S1: When detection begins, the electromagnetic controllable seismic source assemblies 4 on both sides of the drill collar body 2 are started, and the telescopic push rods 7 of the electromagnetic controllable seismic source assemblies 4 extend out and contact the well wall 5. Then, the telescopic push rods 7 continue to apply pressure so that the counterweight shell 6 can press against the well wall 5, so that the electromagnetic controllable seismic source assembly can be close to the well wall, so that the energy of the seismic source can be radiated to the formation to the maximum extent when the seismic source is working.

[0065] S2: In the main control unit 3, the time-frequency information and the source energy output information (output power) of the electromagnetic controllable seismic source assembly 4 are set to ensure that the time-frequency information of the earthquake record is known and to accurately control the delayed emission of multiple electromagnetic controllable seismic source assemblies; after the electromagnetic controllable seismic source assembly 4 is started, the moving coil control counterweight shell 6 inside the electromagnetic controllable seismic source assembly 4 (seismic source) vibrates to stimulate a seismic signal.

[0066] like Figure 6 As shown, again, the present invention also provides a method for seismic wavefront detection while drilling, based on a seismic wavefront detection device while drilling described in any one of the above items, the method for seismic wavefront detection while drilling includes: S1, synthesizing the wavefront excited by each seismic source in the form of a spherical wave into a beam surface through delayed excitation of each controllable seismic source component; S2, receiving seismic records through sensors, processing the seismic data of the controllable seismic source in a cross-correlation manner, analyzing and obtaining the wave velocity of the direct wave, and creating an initial geological velocity model based on the wave velocity result; S3, cutting off the direct wave in the interference seismic record; S4, exciting the seismic record at the source position of the initial geological velocity model to obtain a forward wave field; applying the interference seismic record that actually obtains and cuts off the direct wave in reverse time at the sensor position to obtain a reverse wave field; S5, correlating and superimposing the forward wave field and the reverse wave field to obtain a reverse time migration imaging result based on beamforming.

[0067] The beneficial effect of the technical solution of the present invention is that the propagation angle of the beam surface can be adjusted by different delay settings, and the propagation angle of the beam surface is adjusted according to the forward exploration requirements. By utilizing the multiple controllable seismic sources arranged on both sides of the drill collar and their high-precision signal control characteristics, the forward propagation of seismic waves can be enhanced, and more accurate geological structure imaging results can be obtained through reverse time migration imaging.

[0068] Furthermore, in step S1, the propagation angle of the wavefront is adjusted by different delay settings; wherein the propagation angle of the beam surface is adjusted according to the forward exploration requirements; in step S2, after the velocity of the direct wave is obtained, the velocity value is assigned to the formation to create an initial geological velocity model based on the velocity result.

[0069] The beneficial effect of adopting the above further technical solution is that the propagation angle of the beam surface can be adjusted by different delay settings, and the propagation angle of the beam surface is adjusted according to the forward exploration requirements. By utilizing the multiple controllable seismic sources arranged on both sides of the drill collar and their high-precision signal control characteristics, the forward propagation of seismic waves can be enhanced, and more accurate geological structure imaging results can be obtained through reverse time migration imaging.

[0070] Furthermore, in step S1, when the forward propagation angle is θ, the excitation delay calculation formula between the vibrator components is: Wherein, t1 is the delayed excitation time of the current vibrator assembly relative to the previous vibrator assembly, x1 is the focal distance, v1 is the surrounding rock velocity, and θ is the beam propagation angle; in step S2, the initial geological velocity model is created based on the velocity result by: creating a matrix, the grid size set in the length, width and height directions of the matrix is ​​consistent with the actual stratum, the numerical value in the matrix represents the stratum velocity, and the velocity is the direct wave velocity; the calculation formula of the interferometric seismic record generated by the cross-correlation in the cross-correlation of the vibrator seismic data is: Among them, f(t) is the seismic record, g(t) is the sensor record, t is the integration variable used for full-time integration, τ represents the time delay, and R(t) is the interference seismic record generated by cross-correlation; the calculation formula for the direct wave velocity calculated by the slope of the direct wave component in the seismic record is: v2=x2 / t2, among which v2 is the wave velocity, x2 is the sensor arrangement length, and t2 is the delayed excitation time of the current controllable source assembly relative to the previous controllable source assembly.

[0071] The beneficial effect of adopting the above further technical solution is that the propagation angle of the beam surface can be adjusted by different delay settings, and the propagation angle of the beam surface is adjusted according to the forward exploration requirements. By utilizing the multiple controllable seismic sources arranged on both sides of the drill collar and their high-precision signal control characteristics, the forward propagation of seismic waves can be enhanced, and more accurate geological structure imaging results can be obtained through reverse time migration imaging.

[0072] Embodiment 3:

[0073] The space on both sides of the main control unit 3 on the drill collar body 2 in the axial direction is relatively large, and multiple electromagnetic vibroseis assemblies 4 can be placed to realize the beam forming method. In view of this, the embodiment of the present invention provides a downhole vibroseis seismic wavefront detection method while drilling (seismic wavefront detection method while drilling), such as Figure 3 As shown, the following steps are included:

[0074] S1: Through the delayed excitation of each electromagnetic vibrator assembly 4, the wavefront 9 excited by each source in the form of a spherical wave can be synthesized into a beam surface 10. Through different delay settings, the propagation angle θ (the propagation angle of the wavefront) of the beam surface 10 can be adjusted. The propagation angle θ of the beam surface 10 is adjusted according to the forward exploration requirements. When the forward propagation angle is θ, the excitation delay (excitation delay) between each electromagnetic vibrator assembly 4 is calculated as follows:

[0075]

[0076] Wherein, t1 is the delayed excitation time of the current electromagnetic controllable vibrator assembly 4 relative to the previous electromagnetic controllable vibrator assembly 4, x1 is the focal distance, v1 is the surrounding rock wave velocity, and θ is the beam propagation angle. The delayed excitation time t0 of the first electromagnetic controllable vibrator assembly 4 is 0S, and the delayed excitation time of the nth electromagnetic controllable vibrator assembly 4 is:

[0077]

[0078] S2: The three-component sensor 1 is located in front of the electromagnetic controllable vibrator assembly 4 to receive the seismic reflection wave signal (the specific position can be flexibly arranged and can be not fixed. The specific arrangement design can be carried out according to the actual exploration needs and drilling conditions, as long as it is arranged in groups along the axial direction of the drilling), where the seismic reflection wave signal can be a seismic record. The controllable vibrator seismic data is processed by cross-correlation (correlation processing is performed in a cross-correlation manner) to analyze the direct wave velocity (the direct wave velocity v2=x2 / t2 is calculated by the slope of the direct wave component in the seismic record, where v2 is the wave velocity, x2 is the arrangement length of the three-component sensor, and t2 is the delayed excitation time of the current electromagnetic controllable vibrator assembly 4 relative to the previous electromagnetic controllable vibrator assembly 4, such as Figure 3 and Figure 4 shown);

[0079]

[0080] Where f(t) is the seismic record, g(t) is the three-component sensor record, t is the integration variable for full-time integration (the time variable for performing integration), and R(t) is the interferometric seismic record generated by cross-correlation. τ represents the time delay, and t-τ means that the function f is being delayed by τ time units.

[0081] In this embodiment, a homogeneous initial velocity model is created based on the wave velocity results (eg Figure 4 As shown, after the velocity of the direct wave is obtained, this value is assigned to the stratum. The implementation method is: create a matrix whose "grid size set by the number of grids" in the length, width and height directions is consistent with the actual stratum. The numerical value in the matrix represents the stratum wave velocity, and the wave velocity is the direct wave wave velocity).

[0082] S3: Remove the direct wave signal from the interferometric seismic record.

[0083] S4: Seismic records (here, autocorrelation wavelet records are excited) are excited at the source position of the obtained initial velocity model (initial geological velocity model), and the forward wave field is obtained; the interference seismic records that actually obtain and cut off the direct waves are applied in reverse time at the three-component sensor position to obtain the reverse wave field, and the two wave fields (forward wave field and reverse wave field) are correlated and superimposed to obtain the reverse time migration imaging result based on beamforming.

[0084] 1. The present invention innovatively proposes a seismic wavefront detection device, method, operation method and measurement equipment for drilling, which stimulates seismic signals by vibrating an electromagnetic controllable seismic source component close to the well wall, and utilizes the continuous excitation energy accumulation and controllable seismic signal characteristics to improve the detection capability of long-distance weak reflection signals without damaging the well wall.

[0085] 2. The present invention innovatively proposes an installation method for an electromagnetic controllable seismic source detection device, which makes full use of the space on both sides of the drill collar, and arranges multiple electromagnetic controllable seismic source assemblies and multiple three-component detectors (three-component sensors) along the drilling axis at positions close to the well wall on both sides of the drill collar (drill collar body), which greatly enriches the arrangement, excitation and receiving forms of the seismic source during the drilling process.

[0086] 3. The present invention innovatively proposes a downhole beam forming and reverse time migration imaging method (seismic wave forward detection while drilling method), which utilizes multiple controllable seismic sources arranged on both sides of the drill collar and their high-precision signal control characteristics to achieve the focus enhancement of the forward propagation of seismic waves and obtain more accurate geological structure imaging results through reverse time migration imaging.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A seismic wavefront detection device while drilling, characterized in that: include: Multiple sensors, a drill collar body, a main control unit, and multiple controllable seismic source components. The multiple sensors, the main control unit, and the multiple controllable seismic source components are all installed on the outer wall of the drill collar body, and the multiple sensors and the multiple controllable seismic source components are all connected to the main control unit.

2. The seismic wavefront detection device while drilling according to claim 1, characterized in that: The controllable vibrator assembly includes: a counterweight shell, a telescopic mandrel, and a base, wherein the base is installed on the outer wall of the drill collar body, one end of the telescopic mandrel is connected to the base, and the counterweight shell is installed on the other end of the telescopic mandrel.

3. The seismic wavefront detection device while drilling according to claim 2, characterized in that: The telescopic top rod is an electric telescopic rod, a hydraulic telescopic rod or a pneumatic telescopic rod, and the telescopic top rod is a hollow support frame structure or a solid support plate structure.

4. The seismic wavefront detection device while drilling according to claim 1, characterized in that: Multiple sensors are symmetrically arranged along the central axis of the drill collar body, multiple controllable seismic source components are arranged adjacent to the drill bit, multiple sensors are located between the controllable seismic source component and the drill bit, multiple controllable seismic source components are located on both sides of the main control unit, and multiple controllable seismic source components located on both sides of the main control unit are symmetrically arranged along the central axis of the drill collar body; the sensor is a three-component sensor, and the controllable seismic source component is an electromagnetic controllable seismic source component.

5. A measurement while drilling device, characterized in that: A seismic wavefront detection device while drilling comprising any one of claims 1 to 4 above.

6. A method for operating a seismic wavefront detection device while drilling, characterized in that: Based on the seismic wavefront detection device while drilling according to any one of claims 1 to 4 above, the operation method of the seismic wavefront detection device while drilling includes: S1. When starting detection, start the telescopic function of the vibrator assembly until the vibrator assembly contacts the well wall; S2. Configure the time-frequency information and output power of the vibrator assembly, start the vibration function of the vibrator assembly, and stimulate the seismic signal.

7. The method for operating a seismic wavefront detection device while drilling according to claim 6, characterized in that: In step S1, the telescopic function of the controllable vibrator assembly is activated, and the telescopic top rod of the controllable vibrator assembly is extended until the counterweight housing at the other end of the telescopic top rod abuts against the well wall; In step S2, the main control unit is provided with time-frequency information and output power of the controllable vibrator assembly, the vibration function of the controllable vibrator assembly is started, and the moving coil inside the controllable vibrator assembly controls the counterweight shell to vibrate, thereby exciting a seismic signal.

8. A method for seismic wavefront detection while drilling, characterized in that: Based on the seismic wavefront detection device while drilling according to any one of claims 1 to 4 above, the seismic wavefront detection method while drilling comprises: S1, through the delayed excitation of each controllable source assembly, the wavefront excited by each source in the form of spherical wave is synthesized into a beam surface; S2. Receive seismic records through sensors, process the vibroseis seismic data by cross-correlation, analyze and obtain the velocity of the direct wave, and create an initial geological velocity model based on the velocity results; S3, cutting off the direct wave in the interferometric seismic record; S4, exciting seismic records at the source position of the initial geological velocity model to obtain a forward wave field; applying interferometric seismic records that actually obtain and cut off the direct wave at the sensor position in reverse time to obtain a reverse wave field; S5. Correlate and superimpose the forward propagation wave field and the reverse propagation wave field to obtain a reverse time migration imaging result based on beamforming.

9. A method for seismic wavefront detection while drilling according to claim 8, characterized in that: In step S1, the propagation angle of the wavefront is adjusted by different delay settings; wherein the propagation angle of the beam surface is adjusted according to the forward exploration requirements; in step S2, after the velocity of the direct wave is obtained, the velocity value is assigned to the formation to create an initial geological velocity model based on the velocity result.

10. A seismic wavefront detection while drilling method according to claim 9, characterized in that: In step S1, when the forward propagation angle is θ, the excitation delay calculation formula between each vibrator assembly is: Wherein, t1 is the delayed excitation time of the current vibrator assembly relative to the previous vibrator assembly, x1 is the source spacing, v1 is the surrounding rock wave velocity, and θ is the beam propagation angle; In step S2, The method of creating the initial geological velocity model based on the wave velocity results is as follows: create a matrix, the number of grids in the length, width and height directions of the matrix × the set grid size is consistent with the actual stratum, the value in the matrix represents the stratum wave velocity, and the wave velocity is the direct wave velocity; The calculation formula for the interferometric seismic record generated by cross-correlation in processing vibroseis seismic data by cross-correlation is: Where f(t) is the seismic record, g(t) is the sensor record, t is the integration variable used for full-time integration, τ represents the time delay, and R(t) is the interferometric seismic record generated by cross-correlation; The formula for calculating the direct wave velocity by the slope of the direct wave component in the seismic record is: v2=x2 / t2, Where v2 is the wave velocity, x2 is the sensor array length, and t2 is the delayed excitation time of the current vibrator assembly relative to the previous vibrator assembly.

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