Method for determining optimum frequency of annulus liquid level detection acoustic wave

Abstract

The application discloses a kind of annular space liquid level detection acoustic wave optimal frequency loudness determination method, comprising the following steps: a, calculating annular space liquid level position;B, calculating annular sound speed;C, emitting modulated detection acoustic wave;D, determine the optimal sound intensity under a certain liquid level;E, determine the optimal sound frequency under a certain liquid level;F, determine the optimal sound loudness and frequency under different liquid levels;After each time, the column drill pipe is launched, and is clamped, and steps a-e are repeated, and the corresponding optimal sound loudness and frequency combination under different liquid surface depths are recorded.The application uses electromagnetic acoustic wave as detection sound source, can change the frequency loudness and sound emission time of emitted acoustic wave, and determines the optimal detection frequency loudness corresponding to different liquid surface heights.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of drilling engineering, and particularly relates to a method for measuring optimal frequency and loudness of annular space liquid level detection sound wave. BACKGROUND

[0002] Currently, the echo method is generally used to measure the annular space liquid level, and a high-pressure air gun is used as a sound source. The blast sound source has large energy, and the frequency is generally less than 20 Hz. The sound emission mode has low frequency and large loudness, and the frequency loudness and sound emission time are not adjustable. Low-frequency sound waves attenuate slowly, high-frequency sound waves attenuate quickly, and the coupling is better for high-frequency sound wave reflection. Therefore, the blast sound source has high instantaneous energy, and has certain advantages for deep well and super deep well measurement. However, when measuring the shallow liquid level, the energy of the emitted sound wave in the annular space is too large, and it is difficult to attenuate in the case of shallow liquid level, and it is easy to continuously oscillate in the sound wave channel, so that the liquid level echo is submerged in the emitted sound wave, and the effective information is difficult to extract, resulting in misjudgment of the liquid level position.

[0003] In addition, the penetration of infrasound is strong, and the reflection at the coupling is weak, so that the liquid level position can only be determined by the liquid level echo, and the annular space sound velocity is difficult to determine, resulting in large error. SUMMARY

[0004] The present application aims to overcome the above-mentioned problems in the prior art, and provides a method for measuring the optimal frequency and loudness of annular space liquid level detection sound wave. The electromagnetic sound wave is used as a detection sound source, the frequency and loudness of the emitted sound wave can be changed, and the optimal detection frequency and loudness corresponding to different liquid level heights can be determined.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0006] A method for measuring the optimal frequency and loudness of annular space liquid level detection sound wave, characterized in that it comprises the following steps:

[0007] a. Calculate the annular space liquid level position: drill down to the bottom of the well, grout to the return, start drilling after the liquid level at the wellhead, and calculate the annular space liquid level depth;

[0008] b. Calculate the annular space sound velocity: calculate the annular space sound velocity by collecting the annular space temperature;

[0009] c. Emit modulated detection sound wave: set the modulation sound emission time, frequency and audio, and emit sound wave to the annular space by the electromagnetic sound wave emitter after amplification by the power amplifier;

[0010] d. Determining the optimal sound intensity at a certain liquid level: the sound wave is transmitted downward along the drill pipe in the annulus, returns when encountering the collar and the liquid surface, and the processed collar echo and liquid surface echo are obtained after collecting, filtering and segmenting the echo signal. According to the collar echo and liquid surface echo, the optimal sound intensity at a certain liquid level is determined;

[0011] e. Determining the optimal sound frequency at a certain liquid level: modulating the sound wave with the determined optimal sound intensity, repeating step d, recording the optimal sound frequency at the liquid surface depth, and obtaining the optimal combination of sound intensity and frequency at the liquid surface depth;

[0012] f. Determining the optimal sound intensity and frequency at different liquid levels: after each time a drill pipe is pulled out, the clamp is seated, steps a-e are repeated, and the corresponding optimal sound intensity and frequency combination at different liquid surface depths are recorded.

[0013] In step a, the annulus liquid surface depth is calculated using the formula where l is the annulus liquid surface depth, m; h is the length of the pulled-out drill string, m; r is the outer diameter of the drill pipe, m; and R is the inner diameter of the casing, m.

[0014] In step b, the annulus temperature Tem collected by the temperature sensor is used to calculate the annulus sound speed C = 331.45 + 0.61Tem.

[0015] In step c, the sound wave with a sound emission time of T0 = 0.05s, a frequency f = 1500Hz, and an audio loudness of 100%, 70%, 50%, and 30% is modulated, and then amplified by a power amplifier and emitted into the annulus by an electromagnetic acoustic emitter.

[0016] In step d, the sound wave sensor is responsible for collecting echo data. When the probe sound wave instruction is issued, the sound wave sensor starts collecting data, and this time is defined as the starting point T1. The sound wave sensor samples at a sampling frequency fs for a sampling time T (5 ≤ T ≤ 10), and the sampling signal is s(i).

[0017] In the filtering process of step d, the sampling signal s(i) is filtered by a band-pass filter to obtain the filtered signal sn(i).

[0018] In the segmentation process of step d, the filtered signal sn(i) is divided into two segments. The first segment is the emission segment, with a time of T1-T1+T0, and the emission segment signal is M(t). The second segment is the receiving segment, with a time of T1+T0-T-T1-T0, and the receiving segment signal is s(t).

[0019] In step d, the collar echo and liquid surface echo are detected by detecting the receiving segment signal s(t) and the emission segment signal M(t) using the formula:

[0020]

[0021] Find the maximum point of R(τ), and denote the maximum point as the liquid surface echo point Rmax. Record the time of this point as τ. Then the liquid surface echo time is T0+τ. The depth of the annular liquid surface is: L=C*(T0+τ) / 2. Compare the maximum points of the liquid surface echo corresponding to different sound intensities, and take the sound intensity corresponding to the point with the largest maximum as the optimal sound intensity A1 at this liquid surface depth.

[0022] In step e, after determining the optimal sound intensity, sound waves with a sound emission time of T0 = 0.05s, a loudness of A1, and a frequency of f = 1500-50n (n = 1, 2, 3, ..., 26) are modulated. Step d is repeated, and the optimal sound emission frequency F1 at that liquid depth is recorded to obtain the optimal combination of emission loudness and frequency (L1, A1, F1) at that liquid depth.

[0023] In step f, after each drill pipe is pulled out, the chuck is set, and step ae is repeated to record the optimal combination of loudness and frequency at different liquid depths (L). n A n ,F n ), until the annular liquid level depth L after the n+1 column is removed. n+1 With L n There is no change compared to the previous version.

[0024] The advantages of using this invention are as follows:

[0025] 1. Traditional blasting sound generation methods do not allow for adjustable frequency and loudness. This invention uses an electromagnetic sound wave transmitter as the sound source, and the frequency and loudness of the emitted sound waves can be adjusted, which can effectively improve the recognition effect of shallow liquid surfaces.

[0026] 2. This invention can accurately filter the emitted sound waves according to their frequency, thereby reducing noise interference.

[0027] 3. The cross-correlation detection method used in this invention can improve the recognition rate of echoes.

[0028] 4. This invention uses a temperature sensor to monitor the annular temperature in real time, which can calculate the annular sound velocity in real time and reduce the error in liquid level calculation.

[0029] 5. For different annular liquid levels, the echoes corresponding to detection sound waves of different frequencies and loudnesses are different. This invention can determine the optimal transmission frequency and loudness at different liquid levels, and recommend the optimal frequency and loudness for actual liquid surface detection. Attached Figure Description

[0030] Figure 1 Diagram of echo signal detected by air gun method;

[0031] Figure 2aTime-domain plot of the echo signal of a modulated sound wave with a frequency of 300Hz and a loudness of 100%;

[0032] Figure 2b Correlation detection graph of a modulated acoustic echo signal with a frequency of 300Hz and a loudness of 100%;

[0033] Figure 3a Time-domain plot of the echo signal of a modulated acoustic wave with a frequency of 500Hz and a loudness of 100%;

[0034] Figure 3b Correlation detection graph of a modulated acoustic echo signal with a frequency of 300Hz and a loudness of 100%;

[0035] Figure 4 This is a schematic diagram of the method flow of the present invention;

[0036] Figure 5 This is a schematic diagram of the apparatus involved in the application of the method of the present invention. Detailed Implementation

[0037] Example 1

[0038] Since sound waves of different frequencies and loudnesses propagate differently at different liquid levels, this invention provides the following method to determine the optimal frequency and loudness in order to ensure that the electromagnetic sound wave transmitter can emit the optimal detection frequency and loudness under different liquid level conditions.

[0039] like Figure 4 As shown, the optimal frequency loudness test method is as follows:

[0040] 1. Calculate the position of the annular liquid level.

[0041] First, drill to the bottom of the well, grout until the wellhead is reached, and ensure the grout level is above the wellhead before starting to pull out the drill string, using the formula... Calculate the annular fluid level depth, where l is the annular fluid level depth (m); h is the drill string pull-out length (m); r is the drill pipe outer diameter (m); and R is the casing inner diameter (m).

[0042] 2. Calculate the speed of sound in the annular space.

[0043] Record the temperature sensor data Tem and calculate the speed of sound C = 331.45 + 0.61Tem.

[0044] 3. Transmit modulated detection sound waves through an electromagnetic sound wave transmitter.

[0045] The audio frequencies of 100%, 70%, 50%, and 30% were modulated by a computer, with a sound emission time of T0 = 0.05s, a frequency of f = 1500Hz, and a loudness of 30%. After being amplified by a power amplifier, the audio was emitted by an electromagnetic sound wave transmitter.

[0046] 4. Determine the optimal sound intensity at a given liquid level.

[0047] The sound waves propagate downwards along the drill pipe within the annulus, returning upon encountering the coupling and the fluid surface. The processed effective echoes (coupling echo and fluid surface echo) are obtained after acquiring, filtering, and performing short-time energy calculations on the echo signals.

[0048] 401: The acoustic wave sensor is responsible for collecting echo data. When the computer issues a sound wave detection command, the acoustic wave sensor starts collecting data. This point is defined as the starting point T1. The data acquisition unit samples at a sampling frequency fs, the sampling time is T (5≤T≤10), and the sampling signal is s(i).

[0049] 402: Filtering: The sampled signal s(i) is passed through a bandpass filter to obtain the filtered signal sn(i). The passband range of the filter is 20 to 30 Hz.

[0050] 403: Segmentation: The filtered signal sn(i) is divided into two segments. The first segment is the transmission segment, with a time period of T1 to T1+T0 and a transmission signal of M(t). The second segment is the reception segment, with a time period of T1+T0 to T-T1-T0 and a reception signal of s(t).

[0051] 404: Coupling Wave and Liquid Surface Echo Detection: Correlation detection is performed between the received signal s(t) and the transmitted signal M(t) using the formula:

[0052]

[0053] Find the maximum point of R(τ), and denote the maximum point as the liquid surface echo point Rmax. Record the time of this point as τ. Then the liquid surface echo time is T0+τ. The depth of the annular liquid surface is: L=C*(T0+τ) / 2. Compare the maximum points of the liquid surface echo corresponding to different sound intensities, and take the sound intensity corresponding to the point with the largest maximum as the optimal sound intensity A1 at this liquid surface depth.

[0054] 5. Determine the optimal sound frequency at a given liquid level.

[0055] After determining the sound intensity, the sound waves with a sound emission time of T0 = 0.05s, a loudness of A1, and a frequency of f = 1500-50n (n = 1, 2, 3, ..., 26) are modulated by computer. Step 4 is repeated, and the optimal sound emission frequency F1 at this liquid depth is recorded to obtain the optimal combination of emission loudness and frequency (L1, A1, F1) at this liquid depth.

[0056] 6. Determine the optimal sound volume and frequency at different liquid levels.

[0057] After each drill pipe is retrieved, chuck the drill string and repeat steps 1-5, recording the optimal combination of loudness and frequency for different fluid depths (L).n A n ,F n ), until the annular liquid level depth L after the n+1 column is removed. n+1 With L n There is no change compared to the previous version.

[0058] Example 2

[0059] This embodiment, in conjunction with the accompanying drawings, illustrates specific application examples of the present invention.

[0060] A method for determining the loudness of the optimal frequency of acoustic waves used for annular liquid surface detection, comprising:

[0061] 1. Drill to the bottom of the well, grout until the return point is reached, and begin pulling out the drill string after the fluid level is at the wellhead. Calculate the annular fluid level depth using the formula. Calculate the annular fluid level depth, where l is the annular fluid level depth (m); h is the drill string pull-out length (323m); r is the drill pipe outer diameter (0.127m); and R is the casing inner diameter (0.22237m). Substituting these values ​​into the formula, we get l = 156.35m.

[0062] 2. Install an air-gun type annular liquid level monitor at the throttling manifold to reflect and detect sound waves and record the corresponding echoes. The echo signal is as follows: Figure 1 As shown, the probe wave attenuates too slowly within the annulus, causing the liquid surface echo to be submerged within the emitted wave, making it difficult to accurately identify the starting point of the liquid surface echo.

[0063] 3. Install an electromagnetic sound wave transmitter in the same location.

[0064] a. Calculate the velocity of sound in the aurora: Given a temperature sensor reading of 16℃, the velocity of sound in the aurora is...

[0065] C(16℃)=331.45+0.61*16=341.21m / s

[0066] b. Using an electromagnetic acoustic wave transmitter, detection acoustic waves with different frequency loudness combinations are emitted. The acoustic waves propagate downwards along the drill pipe within the annulus, returning upon encountering the coupling and the liquid surface. The echo signals are collected and filtered, as shown in Figure 2(a) and Figure 3(a). Correlation detection is then performed, resulting in correlation detection diagrams as shown in Figure 2(b) and Figure 3(b). The liquid surface echo time is 0.92s. Therefore, the depth of the liquid surface in the annulus is:

[0067]

[0068] c. As shown in Figures 2(b) and 3(b), when the frequency is 300Hz and the loudness is 100%, the correlation detection value of the liquid surface echo is 1502. When the frequency is 500Hz and the loudness is 100%, the correlation detection value of the liquid surface echo is 612. Therefore, when the depth of the annular liquid surface is 156m, the optimal combination of detection sound waves is 300Hz and 100% loudness.

[0069] There are multiple combinations of sound wave frequency loudness detection. The optimal combination and one of the combinations are listed here. Therefore, it is not limited to the above applications.

[0070] Example 3

[0071] This embodiment describes the apparatus involved in the method of the present invention.

[0072] The apparatus involved in the method of the present invention includes a central processing unit, a preamplifier, a postamplifier, an electromagnetic acoustic wave transmitter, an acoustic wave sensor, a temperature sensor, a solenoid valve, a data acquisition unit, and a filter.

[0073] like Figure 5 As shown in the figure, the markings are: 1-wellbore, 2-drill pipe, 3-annulus, 4-coupling, 5-fluid level, 6-solenoid valve, 7-acoustic sensor, 8-temperature sensor, 9-electromagnetic acoustic transmitter, 10-data acquisition unit, 11-filter, 12-power amplifier, 13-power amplifier, 14-central processing unit, 15-logging data.

[0074] The central processing unit modulates the sound waves, analyzes the echoes, controls the solenoid valves, and calculates the position of the annular fluid level. The emitted sound waves can automatically select the optimal frequency and loudness based on the well structure and fluid depth.

[0075] A preamplifier can amplify the voltage of the modulated audio signal output by the central processing unit, improve the system's signal-to-noise ratio, reduce external interference, and achieve impedance conversion and matching.

[0076] The post-amplifier is responsible for amplifying the audio signal current output from the pre-amplifier, enabling the electromagnetic sound wave transmitter to function properly.

[0077] The electromagnetic sound wave transmitter is responsible for emitting the audio signal output by the post-power amplifier. Its features include adjustable frequency and loudness, with a frequency range of 200 to 1500 Hz and a frequency response range of 70 to 130 dB.

[0078] The acoustic wave sensor is responsible for collecting the emitted and echo signals in the channel. The acoustic wave sensor and the electromagnetic acoustic wave transmitter are in the same channel. There can be one or more of them, and their sensitivities are different. A single acoustic wave transmitter is sensitive to acoustic wave signals within a specific frequency range.

[0079] The temperature sensor is responsible for collecting the temperature in the channel where the audio sensor is located, for the purpose of calculating the speed of sound. It is in the same channel as the sound wave sensor and the electromagnetic sound wave transmitter.

[0080] The solenoid valve is responsible for opening or closing the channel connecting the electromagnetic acoustic transmitter to the annulus. It can automatically open or close according to the needs of the monitoring task. It has a certain pressure resistance and can prevent mud from entering the channel where the electromagnetic acoustic transmitter is located.

[0081] The data acquisition unit is responsible for collecting signals from the solenoid valve, temperature sensor, and acoustic sensor.

[0082] The filter is responsible for filtering the acoustic signals acquired by the data acquisition unit. It can filter out signals outside the frequency range emitted by the electromagnetic acoustic transmitter, reduce noise signals, and improve the signal-to-noise ratio.

Claims

1. A method for determining the loudness of the optimal frequency of acoustic waves used for annular liquid surface detection, characterized in that, Includes the following steps: a. Calculate the annular fluid level position: Drill down to the bottom of the well, grout until the return is seen, start pulling out the drill after the fluid level is at the wellhead, and calculate the depth of the annular fluid level; b. Calculate the velocity of sound in the aura: Calculate the velocity of sound in the aura by collecting the aura temperature data; c. Transmit modulated detection sound waves: Set the modulation time, frequency and audio frequency, and after amplification by a power amplifier, transmit the sound waves into the surrounding space by an electromagnetic sound wave transmitter; d. Determine the optimal sound intensity at a certain liquid level: The sound wave is transmitted downward along the drill pipe in the annulus and returns when it encounters the coupling and the liquid surface. The echo signal is collected, filtered, and segmented to obtain the processed coupling echo and liquid surface echo. Based on the coupling echo and liquid surface echo, the optimal sound intensity at a certain liquid level is determined. In the segmented processing, the filtered signal sn(i) is divided into two segments. The first segment is the transmission segment, with a time period of T1~T1+T0 and a transmission signal of M(t). The second segment is the reception segment, with a time period of T1+T0~T-T1-T0 and a reception signal of s(t). In the detection of docking hoop echo and liquid surface echo, the receiving segment signal s(t) and the transmitting segment signal M(t) are correlated and detected using the formula: right Find the maximum point, and denote the point with the largest maximum as the liquid surface echo point. The time of this point is recorded as follows: The liquid surface echo time is T0+ The depth of the annular liquid level is: Compare the maximum echo points of the liquid surface corresponding to different sound intensity, and take the sound intensity corresponding to the point with the largest maximum as the optimal sound intensity A1 at that liquid surface depth. e. Determine the optimal sound frequency at a certain liquid level: Modulate the sound wave with the determined optimal sound loudness, repeat step d, and record the optimal sound frequency at that liquid level depth to obtain the optimal combination of sound loudness and frequency at that liquid level depth. f. Determine the optimal sound volume and frequency at different liquid levels: After each drill pipe is pulled out, set the chuck and repeat steps ae to record the optimal combination of sound volume and frequency at different liquid depths.

2. The method for determining the optimal frequency loudness of acoustic waves for annular liquid surface detection according to claim 1, characterized in that: In step a, the formula is used. Calculate the depth of the annular liquid level, where The depth of the annular liquid surface is in meters (m). h R is the length of the drill string pulled out, in meters; r is the outer diameter of the drill pipe, in meters; R is the inner diameter of the casing, in meters.

3. The method for determining the optimal frequency loudness of acoustic waves for annular liquid surface detection according to claim 2, characterized in that: In step b, the temperature sensor data Tem is recorded, and the velocity of sound in the surrounding air is calculated. .

4. The method for determining the optimal frequency loudness of acoustic waves for annular liquid surface detection according to claim 3, characterized in that: In step c, sound waves with a duration of T0=0.05s, a frequency of f=1500Hz, and loudness of 100%, 70%, 50%, and 30% are modulated and amplified by a power amplifier and then emitted into the surrounding space by an electromagnetic sound wave transmitter.

5. The method for determining the optimal frequency loudness of acoustic waves for annular liquid surface detection according to claim 4, characterized in that: In step d, the acoustic wave sensor is responsible for collecting echo data. When a sound wave detection command is issued, the acoustic wave sensor starts collecting data. This point is defined as the starting point T1. The acoustic wave sensor samples at a sampling frequency fs, the sampling time is T, and 5≤T≤10. The sampling signal is s(i).

6. The method for determining the optimal frequency loudness of acoustic waves for annular liquid surface detection according to claim 5, characterized in that: In step d, the sampled signal s(i) is passed through a bandpass filter to obtain the filtered signal sn(i).

7. The method for determining the optimal frequency loudness of acoustic waves for annular liquid surface detection according to claim 6, characterized in that: In step e, after determining the optimal sound loudness, sound waves with a sound emission time of T0=0.05s, a loudness of A1, a frequency of f=1500-50n, and n=1,2,3,...,26 are modulated respectively. Step d is repeated, and the optimal sound emission frequency F1 at this liquid depth is recorded to obtain the optimal combination of emission loudness and frequency (L1,A1,F1) at this liquid depth.

8. The method for determining the optimal frequency loudness of acoustic waves for annular liquid surface detection according to claim 7, characterized in that: In step f, after each drill pipe is pulled out, the chuck is set, and step ae is repeated to record the optimal combination of loudness and frequency at different liquid depths (L). n A n ,F n ), until the annular liquid level depth L after the n+1 column is removed. n+1 With L n There is no change compared to the previous version.

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