Marine bidirectional electromagnetic measurement while drilling signal transmission device and method

Abstract

The present invention provides a device and method for transmitting a marine bidirectional electromagnetic measurement while drilling signal. The upper end of the insulating joint is connected to a fixed joint, and the lower end is connected to a transmitting electrode. The transmitting electrode is located below the seabed mud layer. The insulating short joint divides the drill pipe into an upper drill pipe and a lower drill pipe. A bottom hole signal receiving device and a bottom hole instrument control device are installed inside the insulating short joint. A ground data processing device is connected to a ground signal transmitting device. The output end of the ground signal transmitting device is respectively connected to the transmitting electrode and the upper drill pipe through an armored cable. The beneficial effects of the present invention are: when transmitting a marine bidirectional electromagnetic measurement while drilling signal, an insulating joint is used to insulate the transmitting electrode from seawater and mud layers, and by applying pressure on the fixed joint, the transmitting electrode is pressed into the formation, effectively avoiding the attenuation of the signal by the seawater layer and the mud layer, and can effectively improve the quality and depth of the transmission of the marine bidirectional electromagnetic measurement while drilling signal.

Description

Technical Field

[0001] The invention relates to the field of petroleum and mining directional drilling, and in particular to a marine bidirectional electromagnetic measurement-while-drilling signal downlink device and method. Background Art

[0002] With the development of intelligent drilling technology, measurement while drilling technology that transmits logging data from the bottom of the well to the ground in real time has emerged. At present, the measurement while drilling technologies mainly include drilling fluid pulse measurement while drilling technology and electromagnetic measurement while drilling technology. Drilling fluid pulse measurement while drilling technology uses mud pressure waves to transmit bottom hole measurement data, while electromagnetic measurement while drilling technology uses extremely low frequency electromagnetic signals to transmit bottom hole measurement data through drill pipes and formations. In air or foam, since the gas is compressible, it is impossible to generate a pressure pulse signal, resulting in the inability of drilling fluid pulse measurement while drilling to work properly. Electromagnetic measurement while drilling technology is not affected by the circulating medium, does not require moving parts, has a large channel area, and has high structural reliability, and has broad application prospects.

[0003] Bidirectional electromagnetic measurement while drilling technology can transmit data from the bottom of the hole to the surface in real time, while sending commands on the surface, and transmit control commands to the bottom of the hole through the signal channel composed of the formation and the drill pipe, thereby adjusting the transmission frequency and power of the bottom hole instrument, controlling the working status of the bottom hole transmission module and drilling tools, and significantly improving production efficiency.

[0004] The signal transmission of two-way electromagnetic measurement while drilling in the ocean is different from that on land. On the one hand, there are seawater layers and mud layers in offshore drilling, and the resistivity of seawater and mud layers is very low. The electromagnetic signal will be severely attenuated when transmitted in the low-resistivity medium, resulting in the signal strength of offshore drilling being smaller than that of land drilling, and the signal transmission depth is shallow; on the other hand, the seawater fluctuates with the changes in the marine climate, and it is difficult to stably install the ground transmitting electrode at sea level, which seriously affects the quality of signal transmission. Summary of the invention

[0005] The present invention aims to solve the technical problems of limited signal transmission depth and poor signal transmission quality in the ocean in traditional bidirectional electromagnetic measurement while drilling technology. The present invention provides a marine bidirectional electromagnetic measurement while drilling signal transmission device and method, which are conducive to improving the signal transmission depth on the one hand, and can ensure the signal transmission quality on the other hand.

[0006] In order to achieve the above object, the present invention provides a marine bidirectional electromagnetic measurement while drilling signal transmission device, comprising:

[0007] Insulating joints, fixed joints, transmitting electrodes, insulating short joints, drill pipes, bottom hole signal receiving devices, bottom hole instrument control devices, drill bits, ground signal transmitting devices, ground signal processing devices and armored cables;

[0008] The upper end of the insulating joint is connected to the fixed joint through a thread, and the lower end is connected to the transmitting electrode through a thread. The transmitting electrode is located below the seabed mud layer. The insulating short section divides the drill pipe into an upper drill pipe and a lower drill pipe. The bottom hole signal receiving device and the bottom hole instrument control device are installed inside the insulating short section. The ground data processing device is connected to the ground signal transmitting device. The output end of the ground signal transmitting device is respectively connected to the transmitting electrode and the upper drill pipe through an armored cable.

[0009] The ground signal transmitting device converts the control instruction into a low-frequency electrical signal, and transmits the low-frequency electrical signal to the bottom of the well through the transmitting electrode, the formation and the drill pipe. The bottom hole signal receiving device collects the potential difference between the upper drill pipe and the lower drill pipe, and obtains the control instruction after processing, thereby realizing the downward transmission of the marine bidirectional electromagnetic while-drilling measurement signal.

[0010] Preferably, the insulating joint is made of a small section of circular hollow steel pipe, the inner and outer surfaces of the insulating joint body and the upper and lower threaded ends are covered with wear-resistant insulating material, and the buckles of the upper and lower ends of the insulating joint are both female buckles.

[0011] Preferably, the fixed joint is made of a small section of circular hollow steel pipe, the lower end buckle type is a male buckle, the upper and lower ends of the fixed joint are installed with sealing rubber rings, and the hollow part is filled with insulating sealant after the armored cable is installed.

[0012] Preferably, the buckle type of the upper end of the emitting electrode is a male buckle, and there is a fixing screw in the center of the upper end. The armored cable passes through the sealed hollow hole of the fixed joint and the central axis of the insulating joint and is fixed to the screw.

[0013] Preferably, the insulating short section is made of a small section of hollow drill pipe, the insulating short section body and the inner and outer surfaces of the upper and lower threaded ends are covered with wear-resistant insulating material, and the bottom hole signal receiving device and the bottom hole instrument control device are connected and fixed to the upper drill pipe and the lower drill pipe through metal hooks.

[0014] Preferably, the ground signal transmitting device is installed at the top of the upper drill pipe, and the transmitting signal type is a low-frequency sinusoidal alternating current signal.

[0015] Preferably, a waterproof casing is installed at the upper end of the drill pipe located in the seawater layer, and the waterproof casing is extended below the mud layer.

[0016] Preferably, the length of the insulating joint is x meters, where the value range of x is [a, b] meters, 0 <a<b;

[0017] The length of the fixed joint is y meters, where the value range of y is [c, d] meters, 0 <c<d;

[0018] The diameter of the transmitting electrode is z meters, where the value range of z is [e, f] meters, 0 <e<f;

[0019] The horizontal distance between the transmitting electrode and the upper drill pipe is t meters, where the value range of t is [g, h] meters, 0 <g<h。

[0020] In addition, in order to achieve the above-mentioned purpose, the present invention further provides a method for transmitting a marine bidirectional electromagnetic measurement while drilling signal based on the marine bidirectional electromagnetic measurement while drilling signal transmission device, comprising the following steps:

[0021] The surface data processing device receives a control instruction for adjusting the working state of the bottom hole instrument sent by a user terminal (which may be a computer or a mobile phone APP);

[0022] The ground data processing device converts the control instruction into a low-frequency electrical signal, and sends the low-frequency electrical signal to the ground signal transmitting device;

[0023] The ground signal transmitting device applies the low-frequency electrical signal to the upper drill rod and the transmitting electrode through an armored cable;

[0024] The bottom hole signal receiving device collects the potential difference between the upper drill pipe and the lower drill pipe at both ends of the insulating short section, and amplifies, decodes, reduces noise and filters the potential difference to obtain a control instruction transmitted from the surface, and sends the control instruction to the bottom hole instrument control device;

[0025] The bottom hole instrument control device adjusts the working state of the bottom hole instrument according to the control instruction to realize the down transmission process of the marine bidirectional electromagnetic measurement while drilling signal.

[0026] Preferably, the bottom hole instrument comprises a drilling tool and a bottom hole transmitting module, and the control instruction is used to adjust the rotation speed and direction of the drilling tool, and the control instruction is also used to adjust the power and frequency of the bottom hole transmitting module.

[0027] The beneficial effects of the present invention are as follows: when the marine bidirectional electromagnetic measurement while drilling signal is transmitted downward, an insulating joint is used to insulate the transmitting electrode from the seawater and the mud layer, and by applying pressure on the fixed joint, the transmitting electrode is pressed into the formation, thereby effectively avoiding the attenuation of the signal by the seawater layer and the mud layer, and can effectively improve the quality and depth of the transmitted signal of the marine bidirectional electromagnetic measurement while drilling. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of a marine bidirectional electromagnetic measurement while drilling signal transmission device of the present invention;

[0029] Figure 2 is a cross-sectional schematic diagram of the connection between the fixed joint, the insulating joint and the emitting electrode in an embodiment of the present invention;

[0030] Figure 3 This is a flow chart of a method for transmitting marine bidirectional electromagnetic measurement while drilling signals according to the present invention;

[0031] Figure 1 In the middle: 1-fixed joint; 2-insulating joint; 3-transmitting electrode; 4-upper drill pipe; 5-insulating short joint; 6-bottom hole signal receiving device; 7-bottom hole instrument control device; 8-lower drill pipe; 9-drill bit; 10-seawater layer; 11-mud layer; 12-stratum; 13-waterproof casing; 14-ground signal transmitting device; 15-ground signal processing device; 16-armored cable;

[0032] Figure 2 In the figure: 1-1 is the upper sealing rubber ring of the fixed joint; 1-2 is the fixed joint body; 1-3 is the insulating sealant; 1-4 is the lower sealing rubber ring of the fixed joint; 2-1 is the insulating joint body; 2-2 is the wear-resistant insulating material; 3-1 is the fixing screw; 3-2 is the emitter electrode body. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and effect of the present invention more clearly understood, the embodiments of the present invention will now be further described in conjunction with the accompanying drawings.

[0034] Embodiment 1:

[0035] Please refer to Figure 1 , Figure 1 The present invention provides a marine bidirectional electromagnetic measurement while drilling signal transmission device, which includes: a fixed joint 1; an insulating joint 2, a transmitting electrode 3, an upper drill pipe 4, an insulating short joint 5, a bottom hole signal receiving device 6, a bottom hole instrument control device 7, a lower drill pipe 8, a drill bit 9, a seawater layer 10, a mud layer 11, a stratum 12, a waterproof casing 13, a ground signal transmitting device 14, a ground signal processing device 15 and an armored cable 16.

[0036] The upper end of the insulating joint 2 is connected to the fixed joint 1 through a thread, and the lower end is fixed to the transmitting electrode 3 through a thread. By applying pressure on the upper end surface of the fixed joint 1, the entire transmitting electrode 3 is pressed into the mud layer 11; the insulating short section 5 divides the drill pipe into an upper drill pipe 4 and a lower drill pipe 8. The body of the insulating short section 5 and the inner and outer surfaces of the upper and lower threads are covered with wear-resistant insulating materials. The bottom hole signal receiving device 6 and the bottom hole instrument control device 7 are installed inside the insulating short section 5, and the bottom hole signal receiving device 6 is installed on the bottom hole instrument control device 7. The ground data processing device 15 is connected to the ground signal transmitting device 14, and the output end of the ground signal transmitting device 14 is connected to the transmitting electrode 3 and the upper drill pipe 4 through the armored cable 16, the horizontal distance between the transmitting electrode 3 and the upper drill pipe 4 is 300 meters, the ground signal transmitting device 14 is installed at the top of the upper drill pipe 4, and the transmitting signal type is a sinusoidal alternating current signal with a frequency of 5Hz. The waterproof casing 13 is installed at the upper end of the upper drill pipe 4 located in the seawater layer 10, and the waterproof casing 13 is extended to below the mud layer 11;

[0037] During operation, the ground signal transmitting device 14 transmits the control command to the bottom of the well through the transmitting electrode 3, the formation 12, the upper drill pipe 4 and the lower drill pipe 8. The bottom hole signal receiving device 6 collects the potential difference between the upper drill pipe 4 and the lower drill pipe 8 at both ends of the insulating short section 5, and amplifies, decodes, reduces noise, filters and other series of processes on the potential difference to obtain the control command transmitted from the ground, and sends the control command to the bottom hole instrument control device 7; the bottom hole instrument control device 7 adjusts the working state of the bottom hole instrument according to the control command to realize the transmission process of the marine bidirectional electromagnetic downhole measurement signal.

[0038] Embodiment 2:

[0039] Please refer to Figure 2 , Figure 2 It is a cross-sectional schematic diagram of the connection of the fixed joint, the insulating joint and the transmitting electrode in the embodiment of the present invention. The insulating joint 2 is made of a small section of circular hollow steel pipe, and the inner and outer surfaces of the insulating joint body 2-1 and the upper and lower threads are covered with wear-resistant insulating material 2-2, and the length of the insulating joint 2 is 0.5 meters; the fixed joint 1 is made of a small section of circular hollow steel pipe, and the upper and lower ends are installed with an upper sealing rubber ring 1-1 and a lower sealing rubber ring 1-4, and the hollow part is filled with insulating sealant after the armored cable 16 is installed, and the length of the fixed joint 1 is 0.5 meters; there is a fixing screw 3-1 at the center of the upper end of the transmitting electrode 3, and the armored cable 16 is connected to the fixing screw 3-1 after passing through the sealed hollow small hole of the central axis of the fixed joint 1 and the insulating joint 2; the upper and lower ends of the insulating joint 2 are both female buckles, and the lower end of the fixed joint 1 and the upper end of the transmitting electrode 3 are fixed to the insulating joint 2 through a male buckle, and the fixed joint body 1-2, the insulating joint body 2-1 and the transmitting electrode body 3-2 have the same diameter of 0.41 meters.

[0040] Embodiment 3:

[0041] Based on the marine bidirectional electromagnetic measurement while drilling signal transmission device provided in Examples 1 and 2, the specific embodiment of the present invention also provides a marine bidirectional electromagnetic measurement while drilling signal transmission method, please refer to Figure 3 , Figure 3 This is a flow chart of a method for transmitting a marine bidirectional electromagnetic measurement while drilling signal. The method comprises the following steps:

[0042] S1, the ground data processing device 15 receives a control instruction for adjusting the working state of a bottom hole instrument sent by a user terminal;

[0043] S2, the ground data processing device 15 converts the control instruction into a low-frequency electrical signal and sends it to the ground signal transmitting device 14;

[0044] S3, the ground signal transmitting device 14 applies the low-frequency electrical signal to the upper drill rod 4 and the transmitting electrode 3 through the armored cable 16;

[0045] S4, the bottom hole signal receiving device 6 collects the potential difference between the upper drill pipe 4 and the lower drill pipe 8 at both ends of the insulating short section 5, and processes the potential difference through amplification, decoding, noise reduction, filtering, etc. to obtain the control command transmitted from the surface, and sends the control command to the bottom hole instrument control device 7;

[0046] S5. The bottom hole instrument control device 7 adjusts the working state of the bottom hole instrument (rotation speed and direction of the drilling tool, power and frequency of the bottom hole transmitting module, etc.) according to the control instruction to realize the downlink process of the marine bidirectional electromagnetic measurement while drilling signal.

[0047] A specific embodiment of the present invention provides a marine bidirectional electromagnetic measurement while drilling signal transmission device and method. When the marine bidirectional electromagnetic measurement while drilling signal is transmitted, an insulating joint is used to insulate the transmitting electrode from seawater and mud layers, and pressure is applied to the fixed joint to press the transmitting electrode into the formation, thereby effectively avoiding the attenuation of the signal by the seawater layer and the mud layer, and can effectively improve the quality and depth of the marine bidirectional electromagnetic measurement while drilling transmission signal.

[0048] In the absence of conflict, the above embodiments and features in the embodiments may be combined with each other.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A marine bidirectional electromagnetic measurement while drilling signal transmission device, characterized in that: The marine bidirectional electromagnetic measurement while drilling signal transmission device comprises: Insulating joints, fixed joints, transmitting electrodes, insulating short joints, drill pipes, bottom hole signal receiving devices, bottom hole instrument control devices, drill bits, ground signal transmitting devices, ground signal processing devices and armored cables; The upper end of the insulating joint is connected to the fixed joint through a thread, and the lower end is connected to the transmitting electrode through a thread. The transmitting electrode is located below the seabed mud layer. The insulating short section divides the drill pipe into an upper drill pipe and a lower drill pipe. The bottom hole signal receiving device and the bottom hole instrument control device are installed inside the insulating short section. The ground signal processing device is connected to the ground signal transmitting device. The output end of the ground signal transmitting device is respectively connected to the transmitting electrode and the upper drill pipe through an armored cable. The surface signal transmitting device converts the control instruction into a low-frequency electrical signal, and transmits the low-frequency electrical signal to the bottom of the well through the transmitting electrode, the formation and the drill pipe. The bottom-hole signal receiving device collects the potential difference between the upper drill pipe and the lower drill pipe, and obtains the control instruction after processing, thereby realizing the transmission of the marine bidirectional electromagnetic while-drilling measurement signal; The insulating joint is made of a small section of circular hollow steel pipe, the inner and outer surfaces of the insulating joint body and the upper and lower threads are covered with wear-resistant insulating materials, and the buckles of the upper and lower ends of the insulating joint are both female buckles; The fixed joint is made of a small section of circular hollow steel pipe, the lower end buckle type is a male buckle, the upper and lower ends of the fixed joint are installed with sealing rubber rings, and the hollow part is filled with insulating sealant after the armored cable is installed; The buckle type of the upper end of the emitting electrode is a male buckle, and there is a fixing screw in the center of the upper end. The armored cable passes through the sealed hollow small hole of the fixed joint and the central axis of the insulating joint and is fixed with the fixing screw.

2. A marine bidirectional electromagnetic measurement while drilling signal transmission device as claimed in claim 1, characterized in that: The insulating short section is made of a small section of hollow drill pipe, and the inner and outer surfaces of the insulating short section body and the upper and lower threaded ends are covered with wear-resistant insulating materials. The bottom hole signal receiving device and the bottom hole instrument control device are connected and fixed to the upper drill pipe and the lower drill pipe through metal hooks.

3. A marine bidirectional electromagnetic measurement while drilling signal transmission device as claimed in claim 1, characterized in that: The ground signal transmitting device is installed at the top of the upper drill pipe, and the transmitting signal type is a low-frequency sinusoidal alternating current signal.

4. The marine bidirectional electromagnetic measurement while drilling signal transmission device according to claim 1, characterized in that: A waterproof casing is installed at one end of the drill pipe located at the seawater layer, and the waterproof casing is extended below the mud layer.

5. The marine bidirectional electromagnetic measurement while drilling signal transmission device according to claim 1, characterized in that: The length of the insulating joint is x meters, where the value range of x is [a, b] meters, 0 <a<b; The length of the fixed joint is y meters, where the value range of y is [c, d] meters, 0 <c<d; The diameter of the transmitting electrode is z meters, where the value range of z is [e, f] meters, 0 <e<f; The horizontal distance between the transmitting electrode and the upper drill pipe is t meters, where the value range of t is [g, h] meters, 0 <g<h。 6. A method for transmitting a marine bidirectional electromagnetic measurement while drilling signal, based on a marine bidirectional electromagnetic measurement while drilling signal transmitting device according to any one of claims 1 to 5, characterized in that: The method for transmitting the marine bidirectional electromagnetic measurement while drilling signal comprises the following steps: The surface signal processing device receives a control instruction for adjusting the working state of the bottom hole instrument sent by the user terminal; The ground signal processing device converts the control instruction into a low-frequency electrical signal, and sends the low-frequency electrical signal to the ground signal transmitting device; The ground signal transmitting device applies the low-frequency electrical signal to the upper drill rod and the transmitting electrode through an armored cable; The bottom hole signal receiving device collects the potential difference between the upper drill pipe and the lower drill pipe at both ends of the insulating short section, and amplifies, decodes, reduces noise and filters the potential difference to obtain a control instruction transmitted from the surface, and sends the control instruction to the bottom hole instrument control device; The bottom hole instrument control device adjusts the working state of the bottom hole instrument according to the control instruction to realize the down transmission process of the marine bidirectional electromagnetic measurement while drilling signal.

7. A method for transmitting marine bidirectional electromagnetic measurement while drilling signals as claimed in claim 6, characterized in that: The bottom hole instrument comprises a drilling tool and a bottom hole transmitting module. The control instruction is used to adjust the rotation speed and direction of the drilling tool. The control instruction is also used to adjust the power and frequency of the bottom hole transmitting module.

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