阅读说明：本技术 一种电极式近钻头无线短传调制方法及装置 (Electrode type near-bit wireless short-transmission modulation method and device ) 是由 孙云涛 陈文轩 底青云 郑健 张文秀 于 2020-05-14 设计创作，主要内容包括：本发明公开了一种电极式近钻头无线短传调制方法及装置,属于近钻头随钻测井技术领域。该方法包括：通过近钻头测量短节对参数进行测量,获取参数信息并打包成数据包发送至发射处理器部；通过发射处理器部对数据包进行二进制移频键控调制,根据设定的发射功率和驱动源功率,将已调制数据包经过放大电路和驱动电路后加载到发射体正极和发射体负极,通过发射体正极和发射体负极将经过放大电路和驱动电路的已调制数据包发射至接收体,实现电极式无线短传调制。本发明能够实现近钻头无线短传任意长度的调制发射。实现方法简单,根据实际钻井现场的需要可在下井前灵活配置需要发射的信息,方面现场操作人员使用,提高作业效率,降低钻井风险。(The invention discloses an electrode type near-bit wireless short-transmission modulation method and device, and belongs to the technical field of near-bit logging while drilling. The method comprises the following steps: measuring parameters through a near-bit measuring short section, acquiring parameter information, packaging the parameter information into a data packet, and sending the data packet to a transmitting processor part; the data packet is subjected to binary frequency shift keying modulation through the transmitting processor part, the modulated data packet is loaded to the positive pole of the emitter and the negative pole of the emitter after passing through the amplifying circuit and the driving circuit according to the set transmitting power and the set driving source power, and the modulated data packet passing through the amplifying circuit and the driving circuit is transmitted to the receiving body through the positive pole of the emitter and the negative pole of the emitter, so that electrode type wireless short-distance transmission modulation is realized. The invention can realize the modulation emission of near-bit wireless short transmission with any length. The method is simple to implement, information to be transmitted can be flexibly configured before the well is lowered according to the requirements of an actual drilling site, the method is convenient for field operators to use, the operation efficiency is improved, and the drilling risk is reduced.)

1. An electrode type near-bit wireless short-distance transmission modulation method is characterized by comprising the following steps:

measuring parameters through a near-bit measuring short section, acquiring parameter information, packaging the parameter information into a data packet, and sending the data packet to a transmitting processor part;

the data packet is modulated by binary frequency shift keying through the emission processor part, the modulated data packet is loaded to the anode of the emitter and the cathode of the emitter after passing through the amplifying circuit and the driving circuit according to the set emission power and the set driving source power,

the modulated data packet passing through the amplifying circuit and the driving circuit is transmitted to the receiver through the positive electrode of the emitter and the negative electrode of the emitter, and electrode type wireless short-distance transmission modulation is achieved.

2. The electrode type near-bit wireless short-distance transmission modulation method according to claim 1, wherein the near-bit measurement short section measures parameters, acquires parameter information, and packages the parameter information into a data packet, and further comprises the following operations: the front part of the data packet is added into a packet header 0xAA and 0x55, the back part is added with CRC check, and then the data packet is sent to a transmitting processor part.

3. The electrode type near-bit wireless short-distance transmission modulation method according to claim 2, wherein the verification mode is exclusive-OR or addition according to bits.

4. The electrode type near-bit wireless short-distance transmission modulation method according to claim 1, wherein before the transmission processor part performs binary frequency shift keying modulation on the data packet, the method further comprises the following operations: after receiving the data packet, the emission processor part carries out corresponding packet head and CRC detection, if the data packet is correct, the emission processor part takes the whole data packet as information to be emitted to carry out binary frequency shift keying modulation.

5. The electrode type near-bit wireless short-distance transmission modulation method of claim 4, wherein the data packet is modulated according to binary Frequency Shift Keying (FSK) according to the following rule:

bit is 0, carrier f1 is 1.0kHz, and the period is 20;

bit is 1, carrier f2 is 1.5kHz, and the period is 40.

6. The electrode type near-bit wireless short-pass modulation method according to claim 5, characterized in that the transmitting processor part is an STM32 series ARM processor with DAC output function.

7. The electrode type near-bit wireless short-transmission modulation method according to claim 6, wherein the transmission processor part completes modulation of each bit in sequence according to the modulation rule for the data packet to be transmitted, and the transmission time is N x 20ms, wherein N is the total number of transmitted bits.

8. The electrode near-bit wireless short-pass modulation method according to claim 1, wherein the parameters comprise drilling well deviation information, gamma information, revolution number information, instrument state information, and/or temperature information.

9. The electrode type near-bit wireless short-distance transmission modulation method according to claim 1, wherein the data packet is sent to the transmission processor part through a wired 485 interface.

10. An electrode near-bit wireless short-pass modulation system, characterized in that the system performs electrode near-bit wireless short-pass modulation by using the method according to any one of claims 1 to 9, and the system comprises:

the near-bit measuring short section is used for measuring parameters, acquiring parameter information, packaging the parameter information into a data packet and sending the data packet to the transmitting processor part;

a transmitting processor part for carrying out binary frequency shift keying modulation on the data packet, loading the modulated data packet to the positive pole and the negative pole of the emitter after passing through an amplifying circuit and a driving circuit according to the set transmitting power and the set driving source power,

and the emitter anode and the emitter cathode are used for transmitting the modulated data packet passing through the amplifying circuit and the driving circuit to the receiver, so that electrode type wireless short transmission is realized.

Technical Field

The invention belongs to the technical field of near-bit logging while drilling, and particularly relates to an electrode type near-bit wireless short-transmission modulation method and device.

Background

The electrode type near bit wireless short transmission is mainly used for transmitting measurement data of a near bit to an MWD (measurement While Drilling) system by crossing a screw in a wireless mode in a logging While Drilling process. The data is transmitted to a ground system through a mud wave pulse generator of the MWD system or an electromagnetic wave technology, so that a drilling operator is guided to judge the current stratum drilling condition and drilling posture of the drill bit accessory.

As shown in fig. 1, the near-bit wireless short transmission device is composed of a transmitter and a receiver, the transmitter is electrically and mechanically connected with the near-bit measuring short section, and the transmitter is divided into a transmitting positive electrode and a transmitting negative electrode by an isolation layer (GAP). The screw rod is bridged between the emitter and the receiver, the receiver is also divided into a receiving anode and a receiving cathode through the isolating layer, the receiving cathode of the receiver is mechanically and hard linked with the receiving cathode of the emitter (through the screw rod), and thus a current loop is formed from the transmitting anode to the receiving anode and then to the transmitting cathode, and the function of transmitting the information of the near-bit measuring short joint to the MWD of the measurement while drilling system is realized. Because the structural feature of screw rod, generally can not use the through wire to realize the wired communication of transmitting and receiving arrangement, unless reform transform the screw rod structure, use the through wire of pre-buried in the screw rod to realize wired communication. However, this structure has its limitations of use and is essentially abandoned. The development direction of near-bit short transmission is a wireless transmission mode. The wireless short-distance transmission is mainly realized by using an electrode mode or a coil mode.

At this stage, the information provided by the near-bit to the surface field operators mainly includes gamma parameters and well deviation information of the stratum to be drilled. Some operations also need to provide information such as the drilling speed of the drill bit and the battery state of the short section measured by the near drill bit. The gamma information helps to improve the drilling rate (the proportion of the drilled well in the hydrocarbon or coal seam), while the well deviation, the drilling rate and the battery state can assist the drilling operation and improve the efficiency of the drilling. Because the actual operation drilling speed is very slow (related to lithologic components of the stratum to be drilled, the general drilling speed is 10 m/h), the wireless transmission information quantity of the near-bit is not high, and meanwhile, the transmission speed is 0.5-6bps because the MWD system needs to be assisted by mud waves or electromagnetic waves, so that the wireless short transmission speed can reach 20bps to meet the requirement in practical application.

The classical signal transmission modes include baseband transmission and modulated carrier transmission. The baseband transmission is to load the transmitted code element to the channel directly in a binary form without any adjustment, and the method is suitable for short-distance and high-speed communication. Such as high-speed serial communication, SPI communication, etc., has the advantages of high transmission rate, short transmission distance, and poor interference resistance. Another type is carrier communication such as FSK (frequency shift keying modulation), PSK (phase shift keying modulation), and the like. In the field of near-bit wireless short transmission, a baseband transmission mode is not suitable, and carrier communication is suitable for the environment with low speed and large interference in the field.

Disclosure of Invention

In order to solve the problems, the invention provides an electrode type near-bit wireless short-distance transmission modulation method and device by adopting a 2FSK (frequency shift keying), namely a binary frequency modulation keying modulation mode, realizes a signal modulation method for measuring a short section by a near bit in a drilling process, and has simple circuit realization.

According to a first aspect of the invention, an electrode type near-bit wireless short-distance modulation method is provided, and the method comprises the following steps:

measuring parameters through a near-bit measuring short section, acquiring parameter information, packaging the parameter information into a data packet, and sending the data packet to a transmitting processor part;

the data packet is modulated by binary frequency shift keying through the emission processor part, the modulated data packet is loaded to the anode of the emitter and the cathode of the emitter after passing through the amplifying circuit and the driving circuit according to the set emission power and the set driving source power,

the modulated data packet passing through the amplifying circuit and the driving circuit is transmitted to the receiver through the positive electrode of the emitter and the negative electrode of the emitter, and electrode type wireless short-distance transmission modulation is achieved.

Further, the parameters include well deviation information, gamma information, rotational speed information, instrument status information, and/or temperature information.

Further, the data packet is sent to the transmitting processor part through a wired 485 interface.

Further, the near-bit measuring nipple measures parameters, acquires parameter information and packages the parameter information into a data packet, and further comprises the following operations: the front part of the data packet is added into a packet header 0xAA and 0x55, the back part is added with CRC check, and then the data packet is sent to a transmitting processor part.

Further, the check mode is bitwise exclusive-or addition.

Further, before the transmitting processor performs binary frequency shift keying modulation on the data packet, the method further includes the following operations: after receiving the data packet, the emission processor part carries out corresponding packet head and CRC detection, if the data packet is correct, the emission processor part takes the whole data packet as information to be emitted to carry out binary frequency shift keying modulation.

Further, the data packet is modulated according to binary frequency shift keying according to bits, and the modulation rule is as follows:

bit is 0, carrier f1 is 1.0kHz, and the period is 20;

bit is 1, carrier f2 is 1.5kHz, and the period is 40.

Further, the transmission processor section is an STM32 series ARM processor having a DAC output function.

Furthermore, the transmitting processor part completes the modulation of each bit in turn according to the modulation rule for the data packet to be transmitted, the transmitting time is N x 20ms, wherein N is the total number of the transmitted bits.

According to a second aspect of the invention, there is provided an electrode type near-bit wireless short-distance modulation system, the method comprising:

the near-bit measuring short section is used for measuring parameters, acquiring parameter information, packaging the parameter information into a data packet and sending the data packet to the transmitting processor part;

a transmitting processor part for carrying out binary frequency shift keying modulation on the data packet, loading the modulated data packet to the positive pole and the negative pole of the emitter after passing through an amplifying circuit and a driving circuit according to the set transmitting power and the set driving source power,

and the emitter anode and the emitter cathode are used for transmitting the modulated data packet passing through the amplifying circuit and the driving circuit to the receiver, so that electrode type wireless short-distance transmission modulation is realized.

The invention has the beneficial effects that:

by the technical scheme, the near-bit wireless short-transmission modulation transmission with any length can be realized. The method is simple to implement, information to be transmitted can be flexibly configured before the well is lowered according to the requirements of an actual drilling site, the method is convenient for field operators to use, the operation efficiency is improved, and the drilling risk is reduced.

The concrete embodiment comprises the following steps:

1. the invention can realize modulation transmission with any length, when a near-bit instrument is used, field workers (ground geosteering engineers) need to acquire the geosteering information such as bit attitude (well deviation, azimuth, tool face angle), temperature near the bit, formation resistivity, bit drilling speed, annular pressure and the like in real time, but not all the information at any time is acquired (limited by the uploading rate of MWD mud pulse).

2. The modulation mode is simple and practical, the modulation algorithm is realized through processor software, the hardware structure is not influenced by temperature and severe environments such as underground vibration and impact, and the reliability is high.

3. By using the modulation method provided by the invention, the arbitrary information of the measuring short section can be modulated into a signal form transmitted by wireless short transmission, the communication with the measuring short section is simple and feasible, and the communication can be realized through simple 485 communication.

4. The invention fully considers the field environment of the near-bit instrument application and ensures the reliability under the severe environment of high temperature, high vibration and impact. The selected FSK modulation frequency point can reduce the influence of the environment to the maximum extent under the severe underground environment.

5. The near-bit wireless short-distance transmission instrument developed by the invention has completed the field engineering application test, and fully explains the rationality and feasibility of the invention of the part.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 shows a block diagram of a near bit wireless short pass device;

FIG. 2 is a schematic flow chart of a method for wireless short-distance modulation of an electrode-type near-bit according to an embodiment of the invention;

FIG. 3 is a diagram illustrating a packet structure according to an embodiment of the present invention;

FIG. 4 shows a modulation scheme for bits according to an embodiment of the invention;

FIG. 5 is a diagram illustrating a transmit data packet structure according to one embodiment of the present invention;

fig. 6 is a diagram illustrating a structure of a transmission packet according to another embodiment of the present invention.

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the exemplary embodiments below are not intended to represent all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

The terms "first," "second," and the like in the description and in the claims of the present disclosure are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the disclosure described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

A plurality, including two or more.

And/or, it should be understood that, for the term "and/or" as used in this disclosure, it is merely one type of association that describes an associated object, meaning that three types of relationships may exist. For example, a and/or B, may represent: a exists alone, A and B exist simultaneously, and B exists alone.

After the near-bit measuring short section realizes measurement of parameters such as well deviation and gamma of a drilling well, the obtained data are sent to the transmitting processor part through the wired 485 interface. As shown in fig. 2, the transmission processor unit performs 2FSK modulation on the signal, and then according to the currently set transmission power, the modulated signal is applied to the positive and negative electrodes of the emitter after passing through the amplification and driving circuit according to the set driving source power. And electrode type wireless short transmission emission is realized.

As shown in fig. 3, the measured information (gamma, well deviation, number of revolutions, etc.) is formed into a data packet by the short circuit, the header 0xAA and 0x55 is added at the front, the CRC check (the check mode may be bitwise xor or addition) is added at the back, and the length of the whole data packet is determined according to the information that needs to be obtained by ground personnel. The gamma, well deviation, rotating speed, instrument state and the like can be selected, the byte number of each piece of information is determined according to the precision and the measurement range, and 1 byte, 2 bytes and the like can be selected. The longer the length of the data packet, the longer the transmission time, and the larger the corresponding transmission power consumption. The near-bit measuring and transmitting short section is powered by a battery. Therefore, the transmission power consumption is too high, so that the working time of the instrument is reduced, and the long-time application of the field instrument is inconvenient. Therefore, the transmitted information bytes should be selected as briefly as possible to meet the basic requirements.

And after receiving the data packet of the measuring short section, the emission processor part carries out corresponding packet header and CRC detection. If the data packet is correct, the transmitting processor part takes the whole data packet as the information to be transmitted to carry out binary frequency shift keying modulation.

The data packet with transmission is subjected to 2FSK modulation according to bits, and the modulation rule is as follows:

bit is 0, carrier f1 is 1.0kHz period 20

Bit is 1, carrier f2 is 1.5kHz, and the period is 40

The carrier duration after each bit modulation is 20 × 1ms ═ 20ms, the transmitting processor part is an STM32 series ARM processor with DAC output function, and the transmitting processor part completes the modulation of each bit in turn according to the above modulation rule for the data packet to be transmitted. As shown in fig. 4. The time of transmission is N x 20ms, where N is the total number of bits transmitted.