Well logging while drilling data transmission system and transmission method based on underwater acoustic communication technology

Abstract

The invention provides a logging-while-drilling data transmission system and method based on an underwater acoustic communication technology, and the method comprises the steps: enabling logging-while-drilling data to be intelligently compressed through an annular underwater acoustic communication transmitting transducer disposed at the upper end of a logging-while-drilling short section and an annular underwater acoustic communication receiving transducer at a well mouth, and converting the data into a sound wave signal at a well bottom; the drilling fluid is sent from the well bottom to the well mouth in an underwater acoustic communication or acoustic wave mode through a drilling fluid channel in the drill hole. The real-time transmission efficiency of the logging-while-drilling data can be greatly improved through the rate of underwater acoustic communication, and the logging-while-drilling data can be rapidly provided for well drilling engineers in real time. Real-time processing and comprehensive explanation are carried out on logging while drilling data transmitted in real time on a drilling site, and real-time optimization and adjustment of a well track can be carried out according to a comprehensive explanation result, so that intelligent geosteering drilling is realized, the drilling rate of a high-quality reservoir is finally improved, and the oil and gas yield of a single well is increased.

Description

Technical Field

[0001] The invention belongs to the technical field of logging while drilling, and in particular relates to a logging while drilling data transmission system and a transmission method based on hydroacoustic communication technology. Background Art

[0002] Logging While Drilling (LWD) in the oil industry generally refers to measuring the formation rock physical parameters during the drilling process, and using a data telemetry system to send the measurement results to the ground for processing in real time. Due to the limitations of data transmission technology, a large amount of data is stored in the memory of downhole instruments and played back after drilling. Measurement While Drilling (MWD) generally refers to the measurement of drilling engineering parameters, such as well inclination, azimuth, and tool face. Sometimes, MWD refers to all downhole measurements during drilling.

[0003] In the process of oil and gas field exploration and development, logging must be carried out after drilling in order to understand the oil and gas content of the formation. However, the acquisition of logging data is always after the completion of drilling. The instrument is placed in the well with a cable for measurement. However, in some cases, such as a high-angle well with an inclination of more than 65 degrees or even a horizontal well, it is difficult to put the instrument down with a cable; in addition, it is difficult to obtain logging data if the well wall is in poor condition and prone to collapse or blockage. Since drilling fluid is circulated during the drilling process to bring out the drilled cuttings, the drilling fluid filtrate will always invade the formation. Therefore, after drilling, logging is done, and the various parameters of the formation are different from those when the formation is just drilled. So people are thinking, if the logging instrument is placed on the drill bit, the drill bit will have "eyes" and various formation data can be obtained while drilling. This is logging while drilling. In this way, not only can wells of any condition, especially horizontal wells, be logged, but also the measured drilling parameters and formation parameters can be used to adjust the drill bit trajectory in time to make it drill along the direction of the target layer. Since the formation parameters obtained by LWD are the formation parameters just drilled, it is closest to the original state of the formation and is more beneficial for evaluating the oil and gas content in complex formations than general cable logging. The LWD instrument is placed in the drill collar. In addition to measuring conventional logging such as resistivity, sound velocity, neutron porosity, density and some imaging logging, it also measures drilling parameters such as drilling pressure, torque, rotation speed, annular pressure, temperature, chemical composition, etc. Due to the harsh environment, high temperature, great pressure and strong vibration during the drilling process, the reliability of LWD instruments is still the most important issue for merchants.

[0004] The key technology of logging while drilling is signal transmission. The most widely used one is drilling fluid pressure pulse transmission, which is a common method adopted by logging while drilling instruments. It converts the measured parameters into drilling fluid pressure pulses and transmits them to the ground along with the circulation of drilling fluid. After being digitally encoded, the measured parameters become high ("1") and low ("0") electrical signals, which control the mushroom head of the drilling fluid pulse generator. When the code is "1", the mushroom head moves up, increasing the resistance of the drilling fluid flowing through the conical mouth and generating additional pressure. When the code is "0", the mushroom head returns to its original position and the pressure drops to normal. This is a positive pulse transmission system. Similar ones include negative pulse transmission systems and continuous wave transmission systems. The advantages of drilling fluid pressure pulse transmission are economy and convenience, and the disadvantage is low data transmission rate (the number of data bits transmitted per second). In recent years, in order to improve the transmission rate, electromagnetic wave transmission technology has been tried again. It is to place the logging while drilling instrument in a non-magnetic drill collar. There is an insulating short joint between the non-magnetic drill collar and the upper drill pipe, so that the low-frequency electromagnetic wave carrying the measured information can be transmitted to the formation around the well. On the ground, it is detected as the voltage difference between the drilling rig and the ground electrode. Early electromagnetic wave transmission was not commercially available due to large signal attenuation, short transmission distance and high cost. In recent years, due to technological improvements, it has begun to enter the market. Its advantages are high transmission rate and no influence from drilling fluid performance. In addition, there is also a downhole storage method, which stores all data in the downhole storage and recovers the data after drilling. The advantages are low cost and reliable data preservation. The disadvantage is that the ground cannot get data in real time and cannot guide drilling. For logging while drilling with a large amount of data, such as imaging logging while drilling, a combination of real-time transmission and downhole storage is usually adopted. Real-time transmission is used for key well sections, while downhole storage is used for other well sections.

[0005] Underwater communication is very difficult, mainly due to the multipath effect, time-varying effect, narrow available bandwidth, and severe signal attenuation of the channel, especially in long-distance transmission. The rate of underwater communication is very low compared to wired communication because underwater communication uses sound waves instead of radio waves. The common underwater acoustic communication method is to use spread spectrum communication technology, such as CDMA. The development of underwater acoustic communication technology has been relatively mature, and many foreign institutions have developed underwater acoustic communication modems. The main communication methods are: OFDM, spread spectrum and some other modulation methods. In addition, underwater acoustic communication technology has developed to the networking stage. Applying the network technology (Ad Hoc) in radio to the underwater acoustic communication network can realize all-round and three-dimensional communication in the ocean (can be used in combination with unmanned equipment such as AUV and UUV).

[0006] The working principle of underwater acoustic communication technology is to first convert data, text, voice, image and other information into electrical signals through an electric transmitter, and then the encoder digitizes the information, and the transducer converts the electrical signal into an acoustic signal. The acoustic signal passes through the medium of water to transmit the information to the receiving transducer, and then the acoustic signal is converted into an electrical signal. After the decoder deciphers the digital information, the electrical receiver converts the information into sound, data, text and pictures. Summary of the invention

[0007] Aiming at the key problem of signal transmission of logging while drilling, the present invention proposes a logging while drilling data transmission system based on hydroacoustic communication technology, comprising: a logging while drilling instrument short section fixed behind the drill bit, an annular hydroacoustic communication transmitting transducer, an annular hydroacoustic communication receiving transducer and a logging while drilling instrument series; a data output interface is provided at the top of the logging while drilling instrument series; a logging while drilling data acquisition and processing computer arranged on the ground, the logging while drilling data acquisition and processing computer is connected to the annular hydroacoustic communication receiving transducer, and receives the logging while drilling data output by the annular hydroacoustic communication receiving transducer;

[0008] The annular hydroacoustic communication transmitting transducer comprises a data input line, an encoder, a modulator and a power drive amplifier; the annular hydroacoustic communication transmitting transducer is fixed at the upper end of the short section of the logging while drilling instrument;

[0009] The modulator uses orthogonal frequency division multiplexing technology OFDM or spread spectrum and some other modulation methods to modulate the output data of the encoder;

[0010] The annular hydroacoustic communication receiving transducer comprises a preamplifier, a demodulator and a decoder; the annular hydroacoustic communication receiving transducer is installed and fixed on the outer wall of the wellhead cover, below the liquid level of the drilling fluid; the annular hydroacoustic communication receiving transducer and the while-drilling logging instrument series realize acoustic wave communication connection through the annular hydroacoustic communication transmitting transducer and the drilling fluid channel.

[0011] The annular hydroacoustic communication transmitting transducer and the annular hydroacoustic communication receiving transducer are both high temperature resistant, vibration resistant, and wear resistant hydroacoustic communication transducers.

[0012] The logging while drilling instrument short section includes a while drilling acoustic wave measurement module, a while drilling resistivity measurement module, a while drilling neutron porosity measurement module, a while drilling density measurement module, a while drilling radioactive parameter measurement module, a while drilling resistivity and acoustic wave imaging measurement module, and a while drilling nuclear magnetic resonance measurement module.

[0013] The logging while drilling instrument sub also includes a module for measuring bit pressure, torque, rotation speed, annular space pressure, temperature and chemical composition.

[0014] The upper end of the short section of the logging while drilling instrument also includes: a high-temperature resistant multi-channel analog-to-digital conversion module, a high-temperature resistant solid-state memory module, and a high-temperature resistant logging while drilling data intelligent compression and data drive module; the high-temperature resistant logging while drilling data intelligent compression and data drive module is connected to the logging while drilling data output interface.

[0015] The computer for collecting and processing logging data while drilling is placed near the wellhead.

[0016] The LWD data acquisition and processing computer is equipped with a LWD data processing and interpretation module, which processes and interprets the LWD data in real time to understand the lithology and top and bottom interfaces of the strata near the drill bit, optimize and adjust the well trajectory in real time according to the drilling design, realize intelligent geological wire drilling, and improve the drilling rate of high-quality reservoirs.

[0017] The transmission method of the logging while drilling data transmission system based on the hydroacoustic communication technology comprises the following steps:

[0018] a. First, fix the annular hydroacoustic communication transmitting transducer on the upper end of the logging while drilling instrument short section, and connect the data input line of the transmitting transducer to the logging while drilling data output interface;

[0019] b. Install and fix the annular hydroacoustic communication receiving transducer on the outer wall of the wellhead cover below the wellhead, below the liquid level of the drilling fluid;

[0020] c. Lower the drill bit, the drill collar with the short joint of the logging while drilling instrument and the annular hydroacoustic communication transmitting transducer installed and fixed, and the drill pipe connected to the top of the drill collar into the wellbore;

[0021] d. connecting the annular hydroacoustic communication receiving transducer to a logging while drilling data acquisition and processing computer near the wellhead to receive the logging while drilling data output by a decoder of the annular hydroacoustic communication receiving transducer;

[0022] e. After the drill bit and drilling tools are lowered to the bottom of the well, the drilling rig is started and the drill pipe and drill bit are driven to perform drilling operations;

[0023] f. Sending a command to start the operation of the logging while drilling instrument series below the logging while drilling instrument sub to the annular hydroacoustic communication transmitting transducer on the upper part of the drill collar through the logging while drilling data acquisition and processing computer and the receiving annular hydroacoustic communication receiving transducer;

[0024] g. The LWD instrument series at the lower part of the LWD instrument sub starts to collect various independent or combined LWD data downhole;

[0025] h. The logging while drilling data collected by the logging while drilling instrument series at the lower part of the logging while drilling instrument pup section are automatically input into the multi-channel analog-to-digital conversion module to be converted into digital information, and then stored in the high-temperature resistant solid-state memory module, and then input into the high-temperature resistant logging while drilling data intelligent compression and data drive module for intelligent compression processing, and the high-temperature resistant logging while drilling data intelligent compression and data drive module sends the intelligently compressed logging while drilling data to the annular hydroacoustic communication transmitting transducer through the data input line;

[0026] i. The encoder in the annular hydroacoustic communication transmitting transducer first encodes the LWD data after intelligent compression processing, and the modulator modulates the encoded data, which is then transmitted to the power drive amplifier for amplification, and finally the LWD data is sent to the wellhead in the form of sound waves through the drilling fluid or drilling mud channel in the borehole;

[0027] j. An annular hydroacoustic communication receiving transducer installed and fixed on the outer wall of the wellhead cover below the wellhead and below the liquid level of the drilling fluid receives the intelligently compressed LWD data transmitted to the wellhead in the form of sound waves by the annular hydroacoustic communication transmitting transducer through the drilling fluid channel, amplifies the received intelligently compressed LWD data by the built-in preamplifier of the receiving annular hydroacoustic communication transmitting transducer, then transmits the received intelligently compressed LWD data to the demodulator for demodulation, then decodes the data through the decoder, and finally transmits the data to the LWD data acquisition and processing computer for real-time processing;

[0028] k. The computer first decompresses the LWD data from the annular hydroacoustic communication receiving transducer; then uses the LWD data processing and interpretation module to process and interpret the LWD data in real time to understand the lithology and top and bottom interfaces of the formation near the drill bit, optimize and adjust the well trajectory in real time according to the drilling design, realize intelligent geological wire drilling, and improve the drilling rate of high-quality reservoirs;

[0029] 1. Start the LWD data processing software installed in the LWD data acquisition and processing computer, and process the LWD data after decompression in step k in real time to obtain the resistivity, P-wave velocity, S-wave velocity, neutron porosity, radioactive parameters, NMR T and T values, wellbore resistivity imaging and wellbore ultrasonic imaging of the formation or rock formation passed by the LWD sub around the borehole;

[0030] m. Using the logging while drilling data interpretation module installed in the logging while drilling data acquisition and processing computer, the results of the logging while drilling data after the processing in step 1 are comprehensively interpreted to study the lithology type, porosity, permeability, pore fluid composition, oil and gas saturation of the reservoir, movable and unmovable fluids, crack or fault distribution, and the top and bottom interfaces of the formation or rock formation being drilled near the drill bit;

[0031] n. According to the comprehensive interpretation results of step m, observe whether the trajectory of the well drilled into the formation meets the drilling design requirements; if the trajectory of the well drilled into the formation deviates from the pre-designed well trajectory, or the actual well trajectory drilled does not match the formation or rock formation designed to be drilled, it is necessary to optimize and adjust the well trajectory in real time according to the comprehensive interpretation results to achieve intelligent geo-steering drilling, ultimately improve the drilling rate of high-quality reservoirs, and increase the oil and gas production of a single well.

[0032] Beneficial effects of the present invention: The transmission method of the logging while drilling data transmission system based on the hydroacoustic communication technology proposed by the present invention utilizes the annular hydroacoustic communication transmitting transducer installed at the upper end of the logging while drilling short section and the annular hydroacoustic communication receiving transducer installed outside the wellhead cover to convert the logging while drilling data into an acoustic signal at the bottom of the well after intelligent compression, and transmits it from the bottom of the well to the wellhead through the drilling fluid or drilling mud channel in the borehole in the form of hydroacoustic communication. Although the rate of hydroacoustic communication is much lower than the rate of wired communication or radio wave signal transmission, it is much higher than the rate of drilling fluid pressure pulse data transmission that is currently widely used, which can greatly improve the efficiency and reliability of real-time transmission of logging while drilling data and quickly provide logging while drilling data to drilling engineers. By real-time processing and interpretation of the logging while drilling data transmitted in real time using the hydroacoustic communication technology at the drilling site, real-time optimization and adjustment of the well trajectory can be performed to realize intelligent geo-steering drilling, ultimately improving the drilling rate of high-quality reservoirs and increasing the oil and gas production of a single well. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the logging while drilling data transmission system based on the hydroacoustic communication technology of the present invention.

[0034] Figure 2 It is a structural schematic diagram of the upper annular hydroacoustic communication transmitting transducer of the downhole logging while drilling instrument of the present invention.

[0035] Figure 3 The present invention is a schematic structural diagram of the outer annular hydroacoustic communication receiving transducer of the wellhead lower casing.

[0036] Figure 4 The present invention is a schematic diagram of the data transmission process of the logging while drilling data transmission system based on the hydroacoustic communication technology.

[0037] Marks and corresponding parts names in the attached drawings:

[0038] 1- Logging while drilling instrument short section; 2- Annular hydroacoustic communication transmitting transducer; 21- Data input line; 22- Encoder; 23- Modulator; 24- Power drive amplifier; 3- Annular hydroacoustic communication receiving transducer; 31- Preamplifier; 32- Demodulator; 33- Decoder; 4- Logging while drilling instrument series; 5- Data output interface; 6- Logging while drilling data acquisition and processing computer; 7- High temperature resistant multi-channel analog-to-digital conversion module; High temperature resistant solid-state memory module; 9- High temperature resistant Logging while drilling data intelligent compression and data drive module; 10- Surface casing. DETAILED DESCRIPTION

[0039] To facilitate those skilled in the art to understand the technical content of the present invention, the present invention is further explained below with reference to the accompanying drawings.

[0040] Figure 1 The schematic diagram of the logging while drilling data transmission system based on the hydroacoustic communication technology of the present invention. The logging while drilling data transmission system based on the hydroacoustic communication technology comprises a logging while drilling instrument short section 1 installed and fixed behind the drill bit, an annular hydroacoustic communication transmitting transducer 2, an annular hydroacoustic communication receiving transducer 3 and a logging while drilling instrument series 4; the top of the logging while drilling instrument series 4 is provided with a data output interface 5; and a logging while drilling data acquisition and processing computer 6 connected to the annular hydroacoustic communication receiving transducer 3 is provided on the ground.

[0041] Figure 2 The present invention is a schematic diagram of the structure of the annular hydroacoustic communication transmitting transducer on the upper part of the downhole logging while drilling instrument. The annular hydroacoustic communication transmitting transducer 2 includes a data input line 21, an encoder 22, a modulator 23 and a power drive amplifier 24, and the annular hydroacoustic communication transmitting transducer 2 is fixed to the upper end of the short section 1 of the logging while drilling instrument.

[0042] The modulator 23 modulates the output data of the encoder 22 using Orthogonal Frequency Division Multiplexing (OFDM) or spread spectrum or other modulation methods.

[0043] Figure 3 It is a structural schematic diagram of the annular hydroacoustic communication receiving transducer outside the wellhead cover of the present invention. The annular hydroacoustic communication receiving transducer 3 includes a preamplifier 31, a demodulator 32, and a decoder 33. The annular hydroacoustic communication receiving transducer 3 is installed and fixed on the outer wall of the wellhead cover 10, below the liquid level of the drilling fluid; the annular hydroacoustic communication receiving transducer 3 and the logging while drilling instrument series 4 are connected by acoustic wave communication through the annular hydroacoustic communication transmitting transducer 2 and the drilling fluid channel.

[0044] The annular hydroacoustic communication transmitting transducer 2 and the annular hydroacoustic communication receiving transducer 3 are both high temperature resistant, vibration resistant, and wear resistant hydroacoustic communication transducers.

[0045] The logging while drilling instrument sub 1 includes a while drilling acoustic wave measurement module, a while drilling resistivity measurement module, a while drilling neutron porosity measurement module, a while drilling density measurement module, a while drilling radioactive parameter measurement module, a while drilling resistivity and acoustic wave imaging measurement module, a while drilling nuclear magnetic resonance measurement module, etc. The while drilling logging instrument sub 1 also includes modules for measuring drilling pressure, torque, rotation speed, annular pressure, temperature, chemical composition, etc.

[0046] The upper end of the logging while drilling instrument short section 1 also includes a high-temperature resistant multi-channel analog-to-digital conversion module 7, a high-temperature resistant solid-state memory module 8, and a high-temperature resistant logging while drilling data intelligent compression and data drive module 9. The high-temperature resistant logging while drilling data intelligent compression and data drive module 9 is connected to the logging while drilling data output interface 5.

[0047] The LWD data acquisition and processing computer 6 placed near the wellhead is connected to the annular hydroacoustic communication receiving transducer 3 outside the wellhead cover 10 to receive the LWD data output by the decoder 33 of the annular hydroacoustic communication receiving transducer 3 .

[0048] The LWD data acquisition and processing computer 6 is equipped with a LWD data processing and interpretation module, which processes and interprets the LWD data in real time, understands the lithology and top and bottom interfaces of the formation near the drill bit, optimizes and adjusts the well trajectory in real time according to the drilling design, realizes intelligent geological wire drilling, and improves the drilling rate of high-quality reservoirs.

[0049] Figure 4 The data transmission process diagram of the logging while drilling data transmission system based on the hydroacoustic communication technology of the present invention is as follows. The transmission method of the logging while drilling data transmission system based on the hydroacoustic communication technology comprises the following steps:

[0050] The transmission method of the logging while drilling data transmission system based on the hydroacoustic communication technology comprises the following steps:

[0051] a. First, fix the annular hydroacoustic communication transmitting transducer 2 on the upper end of the logging while drilling instrument short section 1, and connect the data input line 21 of the transmitting transducer 2 to the logging while drilling data output interface 5;

[0052] b. Install and fix the annular hydroacoustic communication receiving transducer 3 on the outer wall of the wellhead cover 10 below the wellhead, below the liquid level of the drilling fluid;

[0053] c. lowering the drill bit, the drill collar on which the logging while drilling instrument short section 1 and the annular hydroacoustic communication transmitting transducer 2 are installed and fixed, and the drill pipe connected to the top of the drill collar into the wellbore;

[0054] d. connecting the annular hydroacoustic communication receiving transducer 3 to the logging while drilling data acquisition and processing computer 6 near the wellhead to receive the logging while drilling data output by the decoder 33 of the annular hydroacoustic communication receiving transducer 3;

[0055] e. After the drill bit and drilling tools are lowered to the bottom of the well, the drilling rig is started and the drill pipe and drill bit are driven to perform drilling operations;

[0056] f. Sending a command to start the operation of the logging while drilling instrument series 4 below the logging while drilling instrument sub 1 to the annular hydroacoustic communication transmitting transducer 2 on the upper part of the drill collar through the logging while drilling data acquisition and processing computer 6 and the receiving annular hydroacoustic communication receiving transducer 3;

[0057] g. The logging while drilling instrument series 4 at the lower part of the logging while drilling instrument sub 1 starts to collect various independent or combined logging while drilling data downhole;

[0058] h. The logging while drilling data collected by the logging while drilling instrument series 4 at the lower part of the logging while drilling instrument sub 1 is automatically input into the multi-channel analog-to-digital conversion module 7 to be converted into digital information, and then stored in the high-temperature resistant solid-state memory module 8, and then input into the high-temperature resistant logging while drilling data intelligent compression and data drive module 9 for intelligent compression processing, and the high-temperature resistant logging while drilling data intelligent compression and data drive module 9 sends the intelligently compressed logging while drilling data to the annular hydroacoustic communication transmitting transducer 2 through the data input line 21;

[0059] i. The encoder 22 in the annular hydroacoustic communication transmitting transducer 2 first encodes the LWD data after intelligent compression processing, and the modulator 23 modulates the encoded data, and then transmits it to the power drive amplifier 24 for amplification, and finally sends the LWD data to the wellhead in the form of sound waves through the drilling fluid or drilling mud channel in the borehole;

[0060] j. The annular hydroacoustic communication receiving transducer 3 installed and fixed on the outer wall of the wellhead cover 10 below the wellhead and below the liquid level of the drilling fluid receives the intelligent compressed LWD data transmitted to the wellhead in the form of sound waves by the annular hydroacoustic communication transmitting transducer 2 through the drilling fluid channel, amplifies the received intelligent compressed LWD data by the built-in preamplifier 31 of the receiving annular hydroacoustic communication transmitting transducer 2, then transmits it to the demodulator 32 for demodulation, then decodes it by the decoder 33, and finally transmits it to the LWD data acquisition and processing computer 6 for real-time processing;

[0061] k. The computer 6 for collecting and processing logging while drilling data first decompresses the logging while drilling data from the annular hydroacoustic communication receiving transducer 3; then the logging while drilling data processing and interpretation module is used to process and comprehensively interpret the logging while drilling data in real time to understand the lithology and top and bottom interfaces of the formation near the drill bit, optimize and adjust the well trajectory in real time according to the drilling design, realize intelligent geological wire drilling, and improve the drilling rate of high-quality reservoirs;

[0062] 1. Start the LWD data processing software installed in the LWD data acquisition and processing computer 6, and process the LWD data after decompression in step k in real time to obtain the resistivity, P-wave velocity, S-wave velocity, neutron porosity, radioactive parameters, nuclear magnetic resonance T1 and T2 values, wellbore resistivity imaging and wellbore ultrasonic imaging of the formation or rock formation passed by the LWD sub 1 around the borehole;

[0063] m. Using the logging while drilling data interpretation module installed in the logging while drilling data acquisition and processing computer 6, the results of the logging while drilling data after the processing in step 1 are comprehensively interpreted to study the lithology type, porosity, permeability, pore fluid composition, oil and gas saturation of the reservoir, movable and unmovable fluids, crack or fault distribution, and the top and bottom interfaces of the formation or rock formation being drilled near the drill bit;

[0064] n. According to the comprehensive interpretation results of step m, observe whether the trajectory of the well drilled into the formation meets the drilling design requirements; if the trajectory of the well drilled into the formation deviates from the pre-designed well trajectory, or the actual well trajectory drilled does not match the formation or rock formation designed to be drilled, it is necessary to optimize and adjust the well trajectory in real time according to the comprehensive interpretation results to achieve intelligent geo-steering drilling, ultimately improve the drilling rate of high-quality reservoirs, and increase the oil and gas production of a single well.

Claims

1. The logging while drilling data transmission system based on hydroacoustic communication technology is characterized by: include: A logging while drilling instrument short section (1), an annular hydroacoustic communication transmitting transducer (2), an annular hydroacoustic communication receiving transducer (3) and a logging while drilling instrument series (4) are installed and fixed behind the drill bit; a data output interface (5) is provided at the top of the logging while drilling instrument series (4); a logging while drilling data acquisition and processing computer (6) is arranged on the ground, and the logging while drilling data acquisition and processing computer (6) is connected to the annular hydroacoustic communication receiving transducer (3) to receive the logging while drilling data output by the annular hydroacoustic communication receiving transducer (3); The annular hydroacoustic communication transmitting transducer (2) comprises a data input line (21), an encoder (22), a modulator (23) and a power drive amplifier (24); the annular hydroacoustic communication transmitting transducer (2) is fixed to the upper end of the logging while drilling instrument short section (1); The modulator (23) uses orthogonal frequency division multiplexing technology OFDM or spread spectrum and other modulation methods to modulate the output data of the encoder (22); The annular hydroacoustic communication receiving transducer (3) comprises a preamplifier (31), a demodulator (32) and a decoder (33); the annular hydroacoustic communication receiving transducer (3) is mounted and fixed on the outer wall of the wellhead cover (10) below the liquid level of the drilling fluid; the annular hydroacoustic communication receiving transducer (3) and the logging while drilling instrument series (4) are connected by acoustic wave communication via the annular hydroacoustic communication transmitting transducer (2) and the drilling fluid channel.

2. The logging while drilling data transmission system based on hydroacoustic communication technology according to claim 1 is characterized in that: The annular underwater acoustic communication transmitting transducer (2) and the annular underwater acoustic communication receiving transducer (3) are both high temperature resistant, vibration resistant, and wear resistant underwater acoustic communication transducers.

3. The logging while drilling data transmission system based on hydroacoustic communication technology according to claim 1 is characterized in that: The logging while drilling instrument short section (1) comprises a logging while drilling acoustic wave measurement module, a logging while drilling resistivity measurement module, a logging while drilling neutron porosity measurement module, a logging while drilling density measurement module, a logging while drilling radioactive parameter measurement module, a logging while drilling resistivity and acoustic wave imaging measurement module, and a logging while drilling nuclear magnetic resonance measurement module.

4. The logging while drilling data transmission system based on hydroacoustic communication technology according to claim 3 is characterized in that: The logging while drilling instrument sub (1) also includes a module for measuring drilling pressure, torque, rotation speed, annular pressure, temperature and chemical composition.

5. The logging while drilling data transmission system based on hydroacoustic communication technology according to claim 3 is characterized in that: The upper end of the logging while drilling instrument short section (1) further comprises: a high temperature resistant multi-channel analog-to-digital conversion module (7), a high temperature resistant solid-state memory module (8), and a high temperature resistant logging while drilling data intelligent compression and data drive module (9); the high temperature resistant logging while drilling data intelligent compression and data drive module (9) is connected to the logging while drilling data output interface (5).

6. The logging while drilling data transmission system based on hydroacoustic communication technology according to claim 1 is characterized in that: The computer (6) for collecting and processing logging data while drilling is placed near the wellhead.

7. The logging while drilling data transmission system based on hydroacoustic communication technology according to claim 1 is characterized in that: The logging while drilling data acquisition and processing computer (6) is equipped with a logging while drilling data processing and interpretation module, which processes and interprets the logging while drilling data in real time to understand the lithology and top and bottom interfaces of the formation near the drill bit, optimize and adjust the well trajectory in real time according to the drilling design, realize intelligent geological wire drilling, and improve the drilling rate of high-quality reservoirs.

8. A transmission method for a logging while drilling data transmission system based on hydroacoustic communication technology, characterized in that: The logging while drilling data transmission system based on the hydroacoustic communication technology according to any one of claims 1 to 7 comprises the following steps: (a) firstly fix the annular hydroacoustic communication transmitting transducer (2) on the upper end of the logging while drilling instrument short section (1), and connect the data input line (21) of the transmitting transducer (2) to the logging while drilling data output interface (5); (b) installing and fixing the annular hydroacoustic communication receiving transducer (3) on the outer wall of the wellhead cover (10) below the wellhead and below the liquid level of the drilling fluid; (c) lowering a drill bit, a drill collar on which a logging while drilling instrument short section (1) and an annular hydroacoustic communication transmitting transducer (2) are installed and fixed, and a drill pipe connected to the top of the drill collar into the wellbore; (d) connecting the annular hydroacoustic communication receiving transducer (3) to a logging while drilling data acquisition and processing computer (6) near the wellhead to receive the logging while drilling data output by the decoder (33) of the annular hydroacoustic communication receiving transducer (3); (e) After the drill bit and drilling tools are lowered to the bottom of the well, the drilling rig is started and the drill pipe and drill bit are driven to perform drilling operations; (f) sending an instruction to start the operation of the logging while drilling instrument series (4) below the logging while drilling instrument short section (1) to the annular hydroacoustic communication transmitting transducer (2) on the upper part of the drill collar through the logging while drilling data acquisition and processing computer (6) and the receiving annular hydroacoustic communication receiving transducer (3); (g) The logging while drilling instrument series (4) below the logging while drilling instrument subsection (1) starts collecting various independent or combined logging while drilling data downhole; (h) the logging while drilling data collected by the logging while drilling instrument series (4) at the bottom of the logging while drilling instrument short section (1) is automatically input into the multi-channel analog-to-digital conversion module (7) to be converted into digital information, and then stored in the high-temperature resistant solid-state memory module (8), and then input into the high-temperature resistant logging while drilling data intelligent compression and data drive module (9) for intelligent compression processing, and the high-temperature resistant logging while drilling data intelligent compression and data drive module (9) sends the intelligently compressed logging while drilling data to the annular hydroacoustic communication transmitting transducer (2) through the data input line (21); (i) The encoder (22) in the annular hydroacoustic communication transmitting transducer (2) first encodes the LWD data after the intelligent compression processing, and the modulator (23) modulates the encoded data, and then transmits it to the power drive amplifier (24) for amplification, and finally sends the LWD data to the wellhead in the form of sound waves through the drilling fluid or drilling mud channel in the borehole; (j) an annular hydroacoustic communication receiving transducer (3) installed and fixed on the outer wall of the wellhead cover (10) below the wellhead and below the liquid surface of the drilling fluid, receives the intelligent compressed logging while drilling data transmitted to the wellhead in the form of sound waves by the annular hydroacoustic communication transmitting transducer (2) through the drilling fluid channel, amplifies the received intelligent compressed logging while drilling data by the preamplifier (31) built in the receiving annular hydroacoustic communication transmitting transducer (2), then transmits it to the demodulator (32) for demodulation, then decodes it through the decoder (33), and finally transmits it to the logging while drilling data acquisition and processing computer (6) for real-time processing; (k) The logging while drilling data acquisition and processing computer (6) first decompresses the logging while drilling data from the annular hydroacoustic communication receiving transducer (3); then, using the logging while drilling data processing and interpretation module, the logging while drilling data is processed and comprehensively interpreted in real time to understand the lithology and top and bottom interfaces of the formation near the drill bit, and optimize and adjust the well trajectory in real time according to the drilling design, so as to realize intelligent geological wire drilling and improve the drilling rate of high-quality reservoirs; (1) starting the LWD data processing software installed in the LWD data acquisition and processing computer (6) to process the LWD data after decompression in step (i) in real time, and obtaining the resistivity, P-wave velocity, S-wave velocity, neutron porosity, radioactive parameters, nuclear magnetic resonance T1 and T2 values, wellbore resistivity imaging and wellbore ultrasonic imaging of the formation or rock formation passed by the LWD sub (1) around the borehole; (m) using a logging while drilling data interpretation module installed in the logging while drilling data acquisition and processing computer (6) to comprehensively interpret the results of the logging while drilling data after processing in step (1), and to study the lithology type, porosity, permeability, pore fluid composition, oil and gas saturation of the formation near the drill bit, movable and unmovable fluids, distribution of fractures or faults, and top and bottom interfaces of the formation or rock formation being drilled; (n) Based on the comprehensive interpretation results of step (m), observe whether the trajectory of the well that has been drilled into the formation meets the drilling design requirements; if the trajectory of the well that has been drilled into the formation deviates from the pre-designed well trajectory, or the actual well trajectory that has been drilled does not match the formation or rock formation designed to be drilled, it is necessary to optimize and adjust the well trajectory in real time based on the comprehensive interpretation results to achieve intelligent geo-steering drilling, ultimately improve the drilling rate of high-quality reservoirs, and increase the oil and gas production of a single well.

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