Annular space pressure parameter measuring device, drill collar and measuring method

Abstract

The present invention relates to an annular pressure parameter measuring device, a drill collar and a measuring method, comprising a waveguide body, a resonant cavity is provided inside the waveguide body; a microwave transmitter and a microwave receiver are relatively fixedly installed at two ends in the resonant cavity; a frequency modulator that adjusts the transmission frequency of the microwave transmitter according to the deformation of the waveguide body; a controller that calculates the annular pressure parameter according to the obtained resonant frequency; the frequency modulator is communicatively connected to the microwave transmitter, and the microwave transmitter, the microwave receiver and the frequency modulator are communicatively connected to the controller respectively. The present invention also provides a drill collar and annular pressure parameter measuring method. The present invention has the advantages of accurate measurement, simple structure, good stability and strong applicability, and breaks through the limitations of traditional annular pressure sensors; in addition, since microwave signals are used as measurement parameters, the measurement accuracy is very high, and it has anti-electromagnetic interference, is suitable for underground high temperature and high pressure and strong vibration harsh use environment, and has low maintenance cost.

Description

Technical Field

[0001] The invention relates to the technical field of annular space pressure measurement in oil well drilling, and in particular to an annular space pressure parameter measuring device, a drill collar and a measuring method. Background Art

[0002] In the process of drilling deep and complex deep vertical wells, directional wells including horizontal wells and extended reach wells, the key to drilling success is to keep the drilling fluid density and equivalent circulating density within the safe operating limits of formation fluid pressure, collapse pressure and fracture pressure. Most drilling stoppages are caused by wellbore problems, including circulation loss, formation fluid invasion, differential pressure sticking and unclean wellbore. These downhole problems often lead to a waste of time and a lot of money to deal with accidents. The downhole annular pressure measurement device can measure and record hydrostatic pressure and mud dynamic circulation pressure in real time during drilling, which helps to select the best bottom hole pressure in the narrow fracture pressure and pore pressure safety window; it can monitor wellbore cleaning, excitation pressure and pumping pressure to ensure the stability of the wellbore and the effective monitoring of the pressure loss of the lower drilling tool assembly, and can detect abnormal downhole conditions such as overflow or mud loss at an early stage.

[0003] The annulus pressure sensor of the known existing pressure measurement while drilling device requires the design of a sensor installation cabin, which connects the liquid pressure sensor to the annulus to measure the annulus pressure. Such a structure destroys the sealing structure of the drill collar body and increases the risk of the instrument's sealing being damaged by the ultra-high mud pressure downhole.

[0004] The existing annular pressure measurement methods mostly use metal grid strain measurement, semiconductor strain measurement and quartz crystal resonant strain measurement, which have the disadvantages of high cost, complex installation, weak anti-electromagnetic interference ability, low accuracy, high requirements on working temperature, etc. Therefore, it is urgent to provide an underground annular pressure measurement device suitable for underground high temperature and high pressure and strong vibration harsh use environment with low maintenance cost. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an annulus pressure parameter measuring device, a drill collar and a measuring method, aiming to solve the problems in the prior art.

[0006] The technical solution of the present invention to solve the above technical problems is as follows:

[0007] An annular space pressure parameter measuring device comprises a waveguide body that generates deformation according to the annular space pressure, a resonant cavity is arranged inside the waveguide body; a microwave transmitter and a microwave receiver are relatively fixedly installed at two ends of the resonant cavity;

[0008] A frequency modulator for adjusting the transmission frequency of the microwave transmitter according to the deformation of the waveguide body;

[0009] A controller calculates an annulus pressure parameter according to the obtained resonance frequency;

[0010] The frequency modulator is communicatively connected to the microwave transmitter, and the microwave transmitter, the microwave receiver and the frequency modulator are communicatively connected to the controller respectively.

[0011] The beneficial effects of the present invention are as follows: during the measurement process, first, the waveguide body is deformed according to the annular pressure, the frequency modulator adjusts the transmission frequency of the microwave transmitter according to the deformation of the waveguide body, the microwave receiver sends the received electromagnetic wave signal to the controller, the controller receives the corresponding electromagnetic wave signal and obtains the signal frequency point with the highest amplitude, that is, the frequency point consistent with the resonant frequency of the waveguide body; then, the controller calculates the corresponding annular pressure parameter according to the obtained resonant frequency, and the measurement is convenient and accurate. The present invention has the advantages of accurate measurement, simple structure, good stability and strong applicability, and breaks through the limitations of traditional annular pressure sensors; in addition, since microwave signals are used as measurement parameters, the measurement accuracy is very high, and it has anti-electromagnetic interference, and is suitable for underground high temperature, high pressure and strong vibration harsh use environments, with low maintenance costs, and has great engineering significance and application potential.

[0012] Based on the above technical solution, the present invention can also be improved as follows.

[0013] Furthermore, the frequency modulator includes a resonance point detection circuit for adjusting the emission frequency of the microwave transmitter according to the deformation of the waveguide body, and the resonance point detection circuit is communicatively connected with the microwave transmitter and the controller respectively.

[0014] The beneficial effect of adopting the above further scheme is that during the measurement process, when the waveguide body is deformed under the action of the annular space pressure and the microwave receiver cannot detect the electromagnetic wave signal, the microwave receiver sends the corresponding signal to the controller, and the controller controls the resonance point detection circuit to change the transmission frequency of the electromagnetic wave emitted by the microwave transmitter until the microwave receiver can receive the electromagnetic wave signal, thereby obtaining the corresponding resonance frequency, and then calculating the annular space pressure value corresponding to the resonance frequency, which is convenient for measurement and has high sensitivity.

[0015] Furthermore, the resonance point detection circuit includes a digital frequency synthesizer DDS for generating a swept frequency signal; a power amplifier for converting the swept frequency signal into a microwave power signal; a microwave signal preamplifier, a microwave signal mixer and a low-pass filter for down-converting the resonance frequency; and an AD acquisition circuit for performing analog-to-digital conversion on the swept frequency signal.

[0016] The microwave receiver, microwave signal preamplifier, microwave signal mixer, low-pass filter, AD acquisition circuit, controller, digital frequency synthesizer DDS, power amplifier and microwave transmitter are connected in sequence through lines.

[0017] The beneficial effect of adopting the above further scheme is that during the measurement process, the controller generates a frequency sweep signal through a digital frequency synthesizer DDS, and the frequency sweep signal is converted into a microwave power signal through a power amplifier and loaded onto a microwave transmitter. A certain signal frequency in the frequency sweep microwave signal will be consistent with the resonant frequency point of the waveguide body itself, so that the resonant frequency of the waveguide body can be measured. The resonant frequency is amplified by a microwave receiver connected to a microwave signal preamplifier, and down-converted by a microwave signal mixer and a low-pass filter to generate a frequency sweep signal that meets the sampling rate of the AD acquisition circuit for analog-to-digital conversion, and the controller finds the signal frequency point with the highest amplitude from the microwave frequency sweep signal, that is, the frequency point consistent with the resonant frequency of the waveguide body, and the resonant frequency has a corresponding formula relationship with the annular pressure loaded on the waveguide body, and the resonant frequency is converted into an annular pressure parameter loaded on the waveguide body.

[0018] Furthermore, the waveguide body is in a cylindrical structure, and the resonant cavity extends along the axial direction of the waveguide body.

[0019] The beneficial effects of adopting the above further solution are simple structure, regular shape, convenient installation and space saving.

[0020] Furthermore, a sensing portion is provided on the waveguide body, and a thickness of the sensing portion is smaller than a thickness of the waveguide body.

[0021] The beneficial effect of adopting the above further scheme is that during measurement, since the thickness of the sensing part is smaller than the thickness of the waveguide body, the sensing part on the waveguide body deforms rapidly under the action of the annular space pressure, thereby improving the measurement sensitivity and making the measurement faster, facilitating subsequent operations.

[0022] Furthermore, the sensing portion has a corrugated structure and is distributed circumferentially along the outer wall of the waveguide body.

[0023] The beneficial effects of adopting the above further scheme are simple structure, reasonable design, and the thickness of the sensing part is smaller than the thickness of other parts of the waveguide body, which facilitates sensing of the downhole annular space pressure and causing slight deformation to facilitate subsequent operations.

[0024] The present invention also relates to a drill collar, comprising the annulus pressure parameter measuring device as described above, and also comprising a drill collar body, wherein the interior of the drill collar body is provided with a channel for slurry to pass through, and both ends of the drill collar body are respectively provided with openings connected to the channel; the waveguide body is fixedly mounted on the drill collar body.

[0025] The beneficial effect of adopting the above further solution is that during the measurement process, the waveguide body is fixedly mounted on the drill collar body, and both ends of the drill collar body are respectively connected to the drill pipe and the drill tool assembly to facilitate drilling operations.

[0026] Furthermore, the drill collar body is a cylindrical structure.

[0027] The beneficial effects of adopting the above further solution are simple structure, regular shape, convenient installation and space saving.

[0028] Furthermore, a conical protrusion is provided at one end of the drill collar body, and a conical inner cavity is provided at the other end, and the conical inner cavity is communicated with the two ends of the channel respectively.

[0029] The beneficial effects of adopting the above further solution are simple structure, reasonable design, convenient passage of slurry during drilling, convenient connection of the drill pipe and the drill tool assembly, and convenient disassembly and assembly.

[0030] The present invention also relates to a method for measuring annular pressure parameters while drilling, which specifically comprises the following steps:

[0031] S1: The waveguide body is deformed according to the annular pressure, the frequency modulator adjusts the transmission frequency of the microwave transmitter according to the deformation of the waveguide body, the microwave receiver sends the received electromagnetic wave signal to the controller, and the controller receives the corresponding electromagnetic wave signal and obtains the signal frequency point with the highest amplitude, that is, the frequency point consistent with the resonant frequency of the waveguide body;

[0032] S2: The controller calculates the annular pressure parameter corresponding to the resonant frequency according to the resonant frequency obtained in step S1, and the calculation formula is as follows:

[0033] y0=a0f0 0 +a1f0+a2f0 2 +........+a N f0 N ,

[0034] Where y0 is the loading value of the annular pressure during the first calibration, f0 is the resonant frequency of the waveguide body corresponding to the annular pressure parameter y0, 0-N is a natural number, a0-a N is the coefficient;

[0035] y1=a0+a1f1+a2f1 2 +........+a N f1 N ,

[0036] Where y1 is the loading value of the annular pressure during the second calibration, f1 is the resonant frequency of the waveguide body corresponding to the annular pressure parameter y1, 0-N are natural numbers, a0-a N is the coefficient;

[0037] y2=a0+a1f2+a2f2 2 +........+a N f2 N ,

[0038] Wherein, y2 is the loading value of the annular pressure during the third calibration, f2 is the resonant frequency of the waveguide body corresponding to the annular pressure parameter y2, and 0-N is a natural number;

[0039] …

[0040] y N =a0+a1f N +a2f N 2 +........+a N f N N ,

[0041] Among them, y N is the loading value of the annular pressure during the N+1th calibration, f N is the annular pressure parameter y corresponding to the waveguide body N The resonant frequency at this time, 0-N is a natural number, a0-a N is the coefficient;

[0042] The controller calculates the coefficients a0-a contained in the above N+1 formulas. N , the calculated coefficient a0-a N Substituting the above N+1 formula, we can obtain the following annulus pressure parameter calculation formula:

[0043]

[0044] Wherein, y is the real-time annular pressure parameter loaded on the waveguide body in the well, f is the resonant frequency of the waveguide body corresponding to the annular pressure parameter corresponding to y during downhole measurement, 0-N are natural numbers, a0-a N is the coefficient;

[0045] S3: When working underground, the controller measures the resonant frequency f i Substitute it into the formula of step S2 to obtain the real-time annular pressure parameter downhole.

[0046] The beneficial effect of adopting the above further scheme is that firstly, according to the loading value y of different annular pressures and different resonant frequency values ​​f, the coefficient a0-a in the calibration formula can be obtained. N , and then the final calculation formula of the annular space pressure value is obtained; then, electromagnetic waves are emitted by the microwave transmitter, and after the resonance of the waveguide body, the microwave receiver receives the corresponding electromagnetic waves and sends the corresponding signal to the controller, and the controller obtains the resonant frequency received by the microwave receiver at this time, and calculates the annular space pressure parameter corresponding to the resonant frequency; finally, during downhole measurement, as the measurement depth continues to change, the downhole annular space pressure also changes accordingly. The pressure acting on the sensing part of the waveguide body at each downhole depth is different, that is, as the drilling depth increases, the annular space pressure gradually increases, then the microwave receiver cannot receive the electromagnetic waves emitted by the microwave transmitter. At this time, it is necessary to adjust the frequency of the electromagnetic waves emitted by the microwave transmitter through the frequency modulator until the microwave receiver can receive the corresponding resonant frequency under the annular space pressure. Substituting the resonant frequency value into the corresponding formula can obtain the annular space pressure parameter corresponding to the resonant frequency value, which is convenient for measurement and has higher sensitivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of the structure of the waveguide body in the present invention;

[0048] Figure 2 is a plan view of the waveguide body of the present invention;

[0049] Figure 3 for Figure 2 Cross-sectional view along the BB direction;

[0050] Figure 4 is a circuit block diagram of the present invention;

[0051] Figure 5 It is one of the overall structural schematic diagrams of the present invention;

[0052] Figure 6 This is the second schematic diagram of the overall structure of the present invention;

[0053] Figure 7 for Figure 6 Sectional view along AA direction;

[0054] Figure 8 It is a partial structural schematic diagram of the present invention;

[0055] Fig. 9 This is a flow chart of the annulus pressure parameter measurement of the present invention.

[0056] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0057] 1. Waveguide body; 2. Microwave transmitter; 3. Microwave receiver; 4. Sensing part; 5. Resonance point detection circuit; 6. Drill collar body; 7. Channel; 8. Installation cavity. DETAILED DESCRIPTION

[0058] The principles and features of the present invention are described below in conjunction with the accompanying drawings and specific embodiments. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0059] Example 1

[0060] like Figures 1 to 4 As shown, this embodiment provides an annulus pressure parameter measuring device, comprising:

[0061] A waveguide body 1 is deformed according to the annular space pressure, and a resonant cavity is provided inside the waveguide body 1; a microwave transmitter 2 and a microwave receiver 3 are relatively fixedly installed at two ends of the resonant cavity;

[0062] A frequency modulator for adjusting the transmission frequency of the microwave transmitter 2 according to the deformation of the waveguide body 1;

[0063] A controller calculates an annulus pressure parameter according to the obtained resonance frequency;

[0064] The frequency modulator is communicatively connected with the microwave transmitter 2, and the microwave transmitter 2, the microwave receiver 3 and the frequency modulator are communicatively connected with the controller respectively.

[0065] The measurement principle of this embodiment is as follows: during the measurement process, first, the waveguide body 1 is deformed according to the annular space pressure, the frequency modulator adjusts the transmission frequency of the microwave transmitter 2 according to the deformation of the waveguide body 1, the microwave receiver 3 sends the received electromagnetic wave signal to the controller, the controller receives the corresponding electromagnetic wave signal and obtains the signal frequency point with the highest amplitude, that is, the frequency point consistent with the resonant frequency of the waveguide body 1; then, the controller calculates the corresponding annular space pressure parameter according to the obtained resonant frequency, and the measurement is convenient and accurate.

[0066] This embodiment has the advantages of accurate measurement, simple structure, good stability and strong applicability, and breaks through the limitations of traditional annular pressure sensors. In addition, since microwave signals are used as measurement parameters, the measurement accuracy is very high and it has anti-electromagnetic interference properties. It is suitable for use in underground high temperature, high pressure and strong vibration harsh environments, has low maintenance costs, and has great engineering significance and application potential.

[0067] Preferably, in this embodiment, the microwave transmitter 2 is preferably a microwave transmitting antenna, which is used to transmit electromagnetic waves.

[0068] In addition, the microwave receiver 3 is preferably a microwave receiving antenna, which is used to receive the electromagnetic waves emitted by the microwave transmitter 2 .

[0069] Example 2

[0070] On the basis of Example 1, preferably, in this embodiment, the frequency modulator includes a resonance point detection circuit 5 for adjusting the emission frequency of the microwave transmitter 2 according to the deformation of the waveguide body 1, and the resonance point detection circuit 5 is respectively connected to the microwave transmitter 2 and the controller in communication. During the measurement process, when the waveguide body 1 is deformed under the action of the annular pressure and the microwave receiver 3 cannot detect the electromagnetic wave signal, the microwave receiver 3 sends the corresponding signal to the controller, and the controller controls the resonance point detection circuit 5 to work to change the emission frequency of the electromagnetic wave emitted by the microwave transmitter 2 until the microwave receiver 3 can receive the electromagnetic wave signal, thereby obtaining the corresponding resonance frequency, and then calculating the annular pressure value corresponding to the resonance frequency, which is convenient for measurement and has high sensitivity.

[0071] Example 3

[0072] On the basis of Example 2, in this embodiment, the resonance point detection circuit 5 includes a digital frequency synthesizer DDS for generating a sweep frequency signal; a power amplifier for converting the sweep frequency signal into a microwave power signal; a microwave signal preamplifier; a microwave signal mixer and a low-pass filter for down-converting the resonant frequency; an AD acquisition circuit for performing analog-to-digital conversion on the sweep frequency signal; a microwave receiver 3, a microwave signal preamplifier, a microwave signal mixer, a low-pass filter, an AD acquisition circuit, a controller, a digital frequency synthesizer DDS, a power amplifier, and a microwave transmitter 2 are sequentially connected through lines. During the measurement process, the controller generates a sweep frequency signal through the digital frequency synthesizer DDS, and the sweep frequency signal is converted into a microwave power signal through the power amplifier and loaded onto the microwave transmitter 2. A certain signal frequency in the sweep frequency microwave signal will be consistent with the resonant frequency point of the waveguide body 1 itself, so that the resonant frequency of the waveguide body 1 can be measured. The resonant frequency is amplified by connecting the microwave receiver 3 to the microwave signal preamplifier, and is frequency-reduced by the microwave signal mixer and the low-pass filter to generate a swept frequency signal that meets the sampling rate of the AD acquisition circuit for analog-to-digital conversion. The controller finds the signal frequency point with the highest amplitude from the microwave swept frequency signal, that is, the frequency point consistent with the resonant frequency of the waveguide body 1. The resonant frequency has a corresponding formula relationship with the annular space pressure loaded on the waveguide body 1, and the resonant frequency is converted into the annular space pressure parameter loaded on the waveguide body 1.

[0073] Moreover, the resonance point detection circuit 5 in this embodiment can withstand the high temperature underground, ensuring its normal operation, thereby ensuring the smooth progress of the underground measurement operation.

[0074] Example 4

[0075] On the basis of the above embodiments, in this embodiment, the waveguide body 1 is cylindrical, and the resonant cavity extends axially along the inner cavity of the hollow waveguide body 1. This solution has a simple structure, a regular shape, is easy to install, and saves space.

[0076] In addition to the above embodiments, the waveguide body 1 may also adopt other suitable geometric shapes, such as a structure with a rectangular cross section. Comparatively speaking, this structure occupies a larger space.

[0077] Based on the above scheme, the waveguide body 1 is a metal cylindrical cavity formed by a non-magnetic metal material. From the perspective of high-frequency microwave measurement principles, the waveguide body 1 can be regarded as an LC resonance system of closed inductance and capacitance. When the frequency of the microwave signal rises to a certain level, the LC resonance system is equivalent to reducing the number of turns of the inductor coil L and expanding the distance between the capacitor C plates until it is reduced to a straight wire. Multiple wires are connected in parallel, and as the wires tend to infinity, a closed cylindrical waveguide cavity is obtained. The waveguide cavity has a specific microwave signal resonance point similar to the LC resonance system.

[0078] The resonance point can be obtained by the resonance point detection circuit 5 installed inside the tool drill collar for high-frequency signal frequency sweeping and resonance point monitoring. The resonance point detection circuit 5 generates a sine wave frequency sweeping signal. The signal amplitude output by the frequency sweeping signal source is equal, the frequency sweeping range can be adjusted, and linear frequency sweeping can be achieved. The high-frequency signals of different frequencies generated by the resonance point detection circuit 5 are loaded onto the microwave transmitter 2 installed in the waveguide body 1 through the power amplifier. The microwave signal is received by the microwave receiver 3 after passing through the resonant cavity in the waveguide body 1. When the structural volume size of the waveguide body 1 is fixed, its resonant frequency is a fixed value, and this frequency point can be measured by the resonance point detection circuit 5. When the annular pressure is loaded onto the sensing part 4 of the waveguide body 1, the volume of the microwave resonant cavity of the waveguide body 1 changes, that is, the annular pressure causes a slight change in its volume size after being loaded onto the waveguide body 1, thereby causing the shift of the resonant frequency and the change of the resonant amplitude. The changed resonance point is measured by the resonance point detection circuit 5.

[0079] The dynamic tracking of the resonance point is mainly completed through hardware circuits and software control, and is carried out in the following steps: first, a coarse scan is performed between the start frequency and the end frequency at a larger step frequency to determine the frequency range of the fine scan; then a fine scan is performed at a smaller step frequency to determine the preliminary resonance frequency point and the left and right frequency points; finally, the resonance point of the resonant cavity is calculated based on the results of the fine scan.

[0080] Example 5

[0081] On the basis of Example 4, in this embodiment, a sensing portion 4 is provided on the waveguide body 1, and the thickness of the sensing portion 4 is less than the thickness of the waveguide body 1. During measurement, since the thickness of the sensing portion 4 is less than the thickness of the waveguide body 1, the sensing portion 4 on the waveguide body 1 is rapidly deformed under the action of the annular space pressure, thereby improving the measurement sensitivity and making the measurement speed faster, so as to facilitate the subsequent operation.

[0082] Example 6

[0083] On the basis of Example 5, in this embodiment, the sensing part 4 is in a corrugated structure and is distributed circumferentially along the outer wall of the waveguide body 1. This solution has a simple structure and a reasonable design. The thickness of the sensing part 4 is less than the thickness of other parts of the waveguide body 1, which is convenient for sensing the annular pressure downhole and causing a slight deformation, thereby changing the resonant frequency point of the waveguide body 1 to facilitate subsequent operations.

[0084] The advantage of the above-mentioned sensing part 4 being set as a corrugated structure is that it is more sensitive to external pressure. When external pressure is loaded on the structure, it is more likely to deform than other structures. In addition, the corrugated structure can recover quickly after a slight deformation caused by external pressure, so as to facilitate the subsequent test of the next annular space pressure parameter.

[0085] Preferably, in this embodiment, the position of the sensing portion 4 is not limited, and may be located at the end of the waveguide body 1 , or at any position between the two ends of the waveguide body 1 .

[0086] In addition, the sensing portion 4 is formed into a corrugated structure by a corresponding portion of the waveguide body 1, so as to sense the annular pressure and cause the waveguide body 1 to deform.

[0087] In addition to the above-mentioned embodiment, the above-mentioned sensing portion 4 can also be an annular sensing groove formed by a depression at a corresponding position of the waveguide body 1. Since the thickness of the waveguide body 1 corresponding to the sensing groove is smaller than the corresponding thickness of other parts of the waveguide body 1, the sensing groove is squeezed by the annular pressure under the action of the annular pressure and first undergoes a slight deformation, thereby changing the resonant frequency point of the waveguide body 1, so as to subsequently measure the annular pressure value corresponding to the resonant frequency point.

[0088] Example 7

[0089] like Figures 5 to 8As shown, this embodiment further provides a drill collar, including the annulus pressure parameter measuring device as described in the above embodiments, and also including a drill collar body 6, the drill collar body 6 is provided with a channel 7 for slurry to pass through, and both ends of the drill collar body 6 are respectively provided with openings connected to the channel 7; the waveguide body 1 is fixedly mounted on the drill collar body 6. During the measurement process, the waveguide body 1 is fixedly mounted on the drill collar body 6, and both ends of the drill collar body 6 are respectively connected to the drill pipe and the drill tool assembly, so as to perform drilling operations, and the operation is convenient.

[0090] When the drill collar body 6 is provided, the waveguide body 1 and the resonance point detection circuit 5 are both fixedly mounted on the drill collar body 6, and good sealing is ensured to ensure that each component operates normally underground.

[0091] Preferably, in this embodiment, the drill collar body 6 is provided with a mounting groove, which is formed by a concave surface of the waveguide body 1; the waveguide body 1 is fixedly mounted in the mounting groove. This solution has a simple structure, is easy to install, occupies little space, and saves space.

[0092] Preferably, in this embodiment, one end of the waveguide body 1 is provided with a through hole connected to its internal resonant cavity, the microwave transmitter 2 is fixedly installed at the through hole, and the microwave transmitter 2 is connected to one end of the line, and the other end of the line passes through the through hole and is connected to the resonance point detection circuit 5.

[0093] Preferably, in this embodiment, the drill collar body 6 is further provided with an installation cavity 8 with an open side, the resonance point detection circuit 5 is fixedly installed in the installation cavity 8, and the side wall of the installation cavity 8 is provided with a threading hole for the line connecting the resonance point detection circuit 5 and the microwave transmitter 2 to pass through.

[0094] In addition, a sealing plate is fixedly installed on the open side of the installation cavity 8. After the resonance point detection circuit 5 is installed in the installation cavity 8, the sealing plate is used to seal the open side of the installation cavity 8 to achieve sealing, thereby preventing slurry from entering the installation cavity 8 during drilling and affecting the normal operation of the resonance point detection circuit 5.

[0095] Moreover, a threading hole is provided at one end of the waveguide body 1 close to the microwave transmitter 2 , so as to facilitate the layout of the line connecting the resonance point detection circuit 5 and the microwave transmitter 2 .

[0096] Preferably, in this embodiment, the number of the installation cavities 8 is preferably multiple, and the multiple installation cavities 8 are evenly spaced along the circumference of the drill shank body 6. The multiple installation cavities 8 are respectively used to install various components of the resonance point detection circuit 5, which are easy to install and reasonably distributed; in addition, a sealing plate is fixedly installed on the open side of each installation cavity 8.

[0097] Example 8

[0098] On the basis of Embodiment 7, in this embodiment, the drill collar body 6 is in a cylindrical structure. This solution has a simple structure, a regular shape, is easy to install, and saves space.

[0099] Preferably, in this embodiment, each of the above-mentioned installation cavities 8 is preferably a strip-shaped cavity, and it extends along the axial direction of the drill collar body 6, which can better match the resonance point detection circuit 5 and facilitate installation.

[0100] Example 9

[0101] On the basis of Example 8, in this embodiment, a conical protrusion is provided at one end of the drill collar body 6, and a conical inner cavity is provided at the other end, and they are respectively connected with the two ends of the channel 7. This solution has a simple structure and a reasonable design, is convenient for slurry to pass through during drilling, and is convenient for connecting the drill pipe and the drill tool assembly, and is easy to disassemble and assemble.

[0102] Example 10

[0103] like Fig. 9 As shown, this embodiment also provides a method for measuring annular pressure parameters while drilling, which specifically includes the following steps:

[0104] S1: The waveguide body 1 is deformed according to the annular pressure, the frequency modulator adjusts the transmission frequency of the microwave transmitter 2 according to the deformation of the waveguide body 1, the microwave receiver 3 sends the received electromagnetic wave signal to the controller, the controller receives the corresponding electromagnetic wave signal and obtains the signal frequency point with the highest amplitude, that is, the frequency point consistent with the resonant frequency of the waveguide body 1;

[0105] S2: The controller calculates the annular pressure parameter corresponding to the resonant frequency according to the resonant frequency obtained in step S1, and the calculation formula is as follows:

[0106] y0=a0f0 0 +a1f0+a2f0 2 +........+a N f0 N ,

[0107] Wherein, y0 is the loading value of the annular pressure during the first calibration, f0 is the resonant frequency of the waveguide body 1 corresponding to the annular pressure parameter y0, 0-N is a natural number, a0-a N is the coefficient;

[0108] y1=a0+a1f1+a2f1 2 +........+a N f1 N ,

[0109] Wherein, y1 is the loading value of the annular pressure during the second calibration, f1 is the resonant frequency of the waveguide body 1 corresponding to the annular pressure parameter y1, 0-N are natural numbers, a0-a N is the coefficient;

[0110] y2=a0+a1f2+a2f2 2 +........+a N f2 N ,

[0111] Wherein, y2 is the loading value of the annular space pressure during the third calibration, f2 is the resonant frequency of the waveguide body 1 corresponding to the annular space pressure parameter y2, and 0-N are natural numbers;

[0112] …

[0113] y N =a0+a1f N +a2f N 2 +........+a N f N N ,

[0114] Among them, y N is the loading value of the annular pressure during the N+1th calibration, f N is the annular pressure parameter y corresponding to the waveguide body 1 N The resonant frequency at this time, 0-N is a natural number, a0-a N is the coefficient;

[0115] The controller calculates the coefficients a0-a contained in the above N+1 formulas. N , the calculated coefficient a0-a N Substituting the above N+1 formula, we can obtain the following annulus pressure parameter calculation formula:

[0116]

[0117] Wherein, y is the real-time annular pressure parameter loaded on the waveguide body 1 in the well, f is the resonant frequency of the waveguide body 1 corresponding to the annular pressure parameter y during the downhole measurement, 0-N are natural numbers, a0-a N is the coefficient;

[0118] S3: When working underground, the controller substitutes the measured resonant frequency f into the formula of step S2 to obtain the real-time annular pressure parameter underground;

[0119] The measurement principle of this embodiment is as follows: First, according to the loading value y of different annular pressures and different resonant frequency values ​​f, the coefficient a0-a in the calibration formula can be obtained.N , and then the final calculation formula of the annular space pressure value is obtained; then, electromagnetic waves are emitted by the microwave transmitter 2, and after the resonance of the waveguide body 1, the microwave receiver 3 receives the corresponding electromagnetic waves and sends the corresponding signal to the controller, and the controller obtains the resonant frequency received by the microwave receiver 3 at this time, and calculates the annular space pressure parameter corresponding to the resonant frequency; finally, during downhole measurement, as the measurement depth continues to change, the downhole annular space pressure also changes accordingly, and the pressure acting on the sensing part 4 of the waveguide body 1 at each downhole depth is different, that is, as the drilling depth deepens, the annular space pressure gradually increases, then the electromagnetic waves emitted by the microwave transmitter 2 cannot be received by the microwave receiver, and at this time, the frequency of the electromagnetic waves emitted by the microwave transmitter 2 needs to be adjusted by the frequency modulator until the microwave receiver 3 can receive the corresponding resonant frequency under the annular space pressure, and the resonant frequency value is substituted into the corresponding formula to obtain the annular space pressure parameter corresponding to the resonant frequency value, which is convenient for measurement and has higher sensitivity.

[0120] It should be noted that the above-mentioned annular space pressure parameter y is merely a symbol representing the annular space pressure parameter and has no special meaning. It may also be represented by other appropriate symbols.

[0121] The relationship between the annular pressure parameter y and the resonant frequency f is calibrated using the binomial regression formula, i.e., binomial regression is performed in Excel; the calibration process is only to find the numerical relationship between the annular pressure parameter y and the resonant frequency f, and has nothing to do with the units of the two.

[0122] Based on the annular pressure parameter y, the current well depth can be detected, and a corresponding relationship can be established through historical detection data. As the equipment goes deeper into the well, the pressure parameters and depths of different formations can be learned, so that countermeasures can be prepared in advance for risks at different depths.

[0123] The working principle of the present invention is as follows:

[0124] When in use, the two ends of the drill collar body 6 are respectively connected to the drill pipe and the drill tool assembly, and the drill collar body 6 is extended into the well through the drill pipe to perform corresponding drilling operations;

[0125] During the drilling process, the specific steps for measuring the downhole annular pressure are as follows:

[0126] S1: According to the different annular pressure loading values ​​y and different resonant frequency values ​​f, the coefficient a0-a in the calibration formula can be calculated. N , and then obtain the final calculation formula of the annular pressure value;

[0127] S2: The microwave transmitter 2 emits electromagnetic waves. After the waveguide body 1 resonates, the microwave receiver 3 receives the corresponding electromagnetic waves and sends the corresponding signals to the controller (digital signal processing controller DSPIC33FJ128MC710A of MICROCHIP). The controller obtains the resonance frequency received by the microwave receiver 3 at this time, and calculates the annular pressure parameter corresponding to the resonance frequency.

[0128] S3: During downhole measurement, as the measurement depth changes continuously, the annular pressure in the well also changes accordingly. The pressure acting on the sensing part 4 of the waveguide body 1 is different at each downhole depth, that is, as the drilling depth increases, the annular pressure gradually increases. Then the electromagnetic wave emitted by the microwave transmitter 2 cannot be received by the microwave receiver 3. At this time, it is necessary to adjust the frequency of the electromagnetic wave emitted by the microwave transmitter 2 through the frequency modulator until the microwave receiver 3 can receive the corresponding resonant frequency under the annular pressure. Substituting the resonant frequency into the corresponding formula can obtain the annular pressure parameter corresponding to the resonant frequency, which is convenient for measurement and has higher sensitivity.

[0129] The present invention has the advantages of accurate measurement, simple structure, good stability and strong applicability, breaking through the limitations of traditional annular pressure sensors; in addition, since microwave signals are used as measurement parameters, the measurement accuracy is very high and it has anti-electromagnetic interference properties, is suitable for use in harsh underground environments with high temperature, high pressure and strong vibration, has low maintenance costs, and has great engineering significance and application potential.

[0130] The present invention uses microwaves of a specific resonant frequency to generate a resonance effect in the waveguide body 1 , and after the waveguide body 1 is welded to the drill collar body 6 , the annular pressure loaded outside the waveguide body 1 can be sensed through the microwave signal at a specific frequency point in the waveguide body 1 .

[0131] When the annular pressure loaded on the waveguide body 1 changes, the resonant frequency point of the waveguide body 1 changes, that is, a frequency difference is produced with the microwave signal frequency in the waveguide body 1. At this time, the resonant frequency point of the resonant point detection circuit 5 installed inside the drill collar body 6 and the microwave antenna in the waveguide body 1 can be re-scanned. The resonant point forms a certain calibration formula relationship with the different annular pressures loaded on the resonant point detection circuit 5.

[0132] When the entire tool is working underground, changes in the annular pressure outside the drill collar body 6 will cause a slight deformation of the sensing part 4 on the resonance point detection circuit 5, thereby changing the resonance frequency point of the waveguide body 1 and causing it to shift. The changed resonance frequency point is measured by the resonance point detection circuit 5 and the microwave antenna in the waveguide body 1, and the current annular pressure can be calculated through the calibration formula between the resonance point and different annular pressures.

[0133] This waveguide body 1 annular pressure sensor has the advantages of accurate measurement, simple structure, good stability and strong applicability, breaking through the limitations of traditional annular pressure sensors; in addition, since microwave signals are used as measurement parameters, the measurement accuracy is very high and it has anti-electromagnetic interference. It is suitable for underground high temperature, high pressure and strong vibration harsh use environment, with low maintenance cost, and has great engineering significance and application potential.

[0134] In actual application, the tool drill collar provided by the present invention monitors the real-time annular pressure parameters of the well. Taking a 3000-meter well as an example, under normal circumstances, the annular pressure parameters of the well fluctuate stably within the range of 60-70MPa. The tool drill collar provided by the present invention monitors the annular pressure parameters of the well in the range of 60-140MPa.

[0135] When the annular pressure parameter suddenly increases to 100-110MPa due to formation pressure somewhere underground, that is, when the annular pressure parameter range of the drill collar monitoring the underground is 100-110MPa, the underground annular pressure parameter fluctuates greatly, indicating that the underground annular pressure is abnormal at this time, which is easy to cause well kick or blowout. At this time, the staff can adjust the density of the injected drilling fluid or the pressure of the drilling fluid delivery pump according to the actual situation to prevent well kick or blowout and ensure safe production.

[0136] It should be noted that the above-mentioned electronic components involved in the present invention all adopt the existing technology, and the above-mentioned components are electrically connected to each other and to the controller, and the control circuit between the controller and each component is the existing technology.

[0137] In addition, when in use, a power supply device such as a battery is placed on the ground during drilling, which is connected to the resonance point detection circuit 5 through a line to provide power to ensure normal operation.

[0138] 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. An annulus pressure parameter measuring device, characterized in that: It comprises a waveguide body (1) that deforms according to annular space pressure, wherein a resonant cavity is provided inside the waveguide body (1); a microwave transmitter (2) and a microwave receiver (3) are relatively fixedly mounted at two ends of the resonant cavity; adjusting the emission frequency of the microwave transmitter (2) according to the deformation of the waveguide body (1); FM; A controller calculates an annulus pressure parameter according to the obtained resonance frequency; The frequency modulator is in communication connection with the microwave transmitter (2), and the microwave transmitter (2) The microwave receiver (3) and the frequency modulator are respectively connected to the controller for communication; The method for measuring annular space pressure parameters using the device includes the following steps: S1: the waveguide body (1) deforms according to the annular pressure, the frequency modulator adjusts the transmission frequency of the microwave transmitter (2) according to the deformation of the waveguide body (1), the microwave receiver (3) sends the received electromagnetic wave signal to the controller, the controller receives the corresponding electromagnetic wave signal and obtains the signal frequency point with the highest amplitude, that is, the frequency point consistent with the resonant frequency of the waveguide body (1); S2: The controller calculates the resonant frequency according to the resonant frequency obtained in step S1. The corresponding annulus pressure parameter is calculated as follows: ， Wherein, y0 is the loading value of the annular pressure during the first calibration, and f0 is the pressure of the waveguide body (1) on The resonant frequency when the annular pressure parameter is y0, N is a natural number, a0-a N is the coefficient; ， Wherein, y1 is the loading value of the annular space pressure during the second calibration, and f1 is the pressure of the waveguide body (1) on The resonant frequency when the annular pressure parameter is y1, N is a natural number, a0-a N is the coefficient; ， Wherein, y2 is the loading value of the annular space pressure during the third calibration, and f2 is the pressure of the waveguide body (1) on The resonant frequency when the annular pressure parameter is y2, N is a natural number; …… ， Among them, y N is the loading value of the annular pressure during the N+1th calibration, f N The waveguide body (1) Corresponding annulus pressure parameter y N The resonant frequency when N is a natural number, a0-a N is the coefficient; The controller calculates the coefficients a0-a contained in the above N+1 formulas. N , the calculated coefficient a0-a N Substituting the above N+1 formulas, we can obtain the following annulus pressure parameter calculation formula: ， Wherein, y is the real-time annular pressure parameter loaded on the waveguide body (1) downhole, and f is When measuring downhole, the resonant frequency of the waveguide body (1) corresponding to the annular pressure parameter corresponding to y, N is a natural number, a0-a N is the coefficient; S3: When working underground, the controller substitutes the measured resonant frequency f into the step S2 The real-time annular pressure parameters of the well are obtained from the formula.

2. The annular space pressure parameter measuring device according to claim 1, characterized in that: The frequency modulator comprises a resonance point detection circuit (5) for adjusting the emission frequency of the microwave transmitter (2) according to the deformation of the waveguide body (1); the resonance point detection circuit (5) is respectively connected to the microwave transmitter (2) and the controller for communication.

3. The annular space pressure parameter measuring device according to claim 2 is characterized in that: The resonance point detection circuit (5) comprises: Digital frequency synthesizer DDS, used to generate swept frequency signal; A power amplifier, used for converting the frequency sweep signal into a microwave power signal; Microwave signal preamplifier; A microwave signal mixer and a low-pass filter are used to reduce the frequency of the signal at the resonant frequency; AD acquisition circuit, used for performing analog-to-digital conversion on the frequency sweep signal; The microwave receiver (3), the microwave signal preamplifier, the microwave signal mixer, the low-pass filter, the AD acquisition circuit, the controller, the digital frequency synthesizer DDS, the power amplifier and the microwave transmitter (2) are connected in sequence via lines.

4. The annular space pressure parameter measuring device according to any one of claims 1 to 3, characterized in that: The waveguide body (1) is of cylindrical structure, and the resonant cavity extends axially along the inner cavity of the hollow waveguide body (1).

5. The annular space pressure parameter measuring device according to claim 4 is characterized in that: An induction portion (4) is provided around the waveguide body (1), and the thickness of the induction portion (4) is smaller than the thickness of the waveguide body (1).

6. The annular space pressure parameter measuring device according to claim 5, characterized in that: The sensing portion (4) has a corrugated structure and is distributed circumferentially along the outer wall of the waveguide body (1).

7. A drill collar, characterized in that: The invention comprises an annulus pressure parameter measuring device as claimed in any one of claims 1 to 6, and further comprises a drill collar body (6), wherein a channel (7) for drill pipe slurry to pass through is provided inside the drill collar body (6), and openings communicating with the channel (7) are provided at both ends of the drill collar body (6); the annulus pressure parameter measuring device is fixedly mounted on the drill collar body (6).

8. The drill collar according to claim 7, characterized in that: The drill collar body (6) is of cylindrical structure.

9. The drill collar according to claim 8, characterized in that: One end of the drill collar body (6) is provided with a conical protrusion, and the other end is provided with a conical inner cavity, which are respectively connected to the two ends of the channel (7).

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