Device for quantitatively measuring well cementation quality of second cementation surface

Abstract

The utility model discloses a device for quantitatively measuring the well cementation quality of a second cementation surface, which comprises a metal grooving pipe shell, an upper connector, an upper transmitting transducer, an upper sound insulator, a first receiving transducer, a second receiving transducer, a third receiving transducer, a fourth receiving transducer, a fifth receiving transducer, a sixth receiving transducer, a lower sound insulator, a lower transmitting transducer and a lower connector which are sequentially connected together are packaged in the metal grooving pipe. According to the device disclosed by the utility model, the six groups of receiving transducers are packaged by adopting the receiving integrated acoustic window, so that the number of fixed ends of the receiving acoustic window is reduced, the direct waves of sound waves at joints are reduced, and meanwhile, each group of receiving transducers are ensured to have a wider incident sound field.

Description

Technical Field

[0001] The utility model belongs to the field of petroleum well logging, and particularly relates to a device and method for quantitatively measuring the second cementing surface cementing quality in the field, which can evaluate the cement bonding condition between the casing and the formation. Background Art

[0002] Cementing is a construction operation that involves placing casing into a wellbore and injecting cement between the wellbore and the casing. This ultimately supports and protects the casing in the oil and gas well, and can isolate oil, gas, and water layers. During the oil and gas extraction process, the quality of cement bonding will directly affect the service life and safety of the well, as well as the smooth implementation of the entire water injection and natural gas development process. Therefore, cementing is an indispensable and important step in practical work. The acoustic wave detection method based on wellbore acoustic theory is an important means of evaluating cementing quality. This method is generally implemented using an acoustic amplitude variable density logging device, which mainly uses a transmitting transducer to excite the acoustic wave signal and a receiving transducer arranged at a distance of 3ft and 5ft from the transmitter to receive the acoustic wave signal. The 3ft log receives casing wave signals and measures the amplitude of the first wave to reveal the bond between the casing and the cement sheath at the first interface. This measurement curve is called CBL (Cement Bond Logging). The 5ft log receives the full wave train information over a specific time period and plots patterns of varying grayscale, also known as variable density logs (VDLs). The intensity of these patterns reflects the bond between the cement sheath and the formation at the second interface. While CBL logs can be quantitatively interpreted, the interpretation of VDL data remains largely qualitative, requiring interpreters to analyze each segment individually. This not only reduces data processing efficiency but also creates variability in interpretation between different interpreters, impacting cementing quality assessment. Utility Model Content

[0003] The technical problem to be solved by the utility model is to address the deficiencies in the qualitative analysis method of the VDL logging data of the acoustic amplitude variable density logging device, and to provide a device and method for quantitatively measuring the cementing quality of the second cementation surface. In addition to having the CBL and VDL measurement functions of conventional instruments, the utility model can also realize quantitative evaluation of the second cementation surface, thereby improving the efficiency of logging data processing and the objectivity of logging interpretation.

[0004] The utility model adopts the following technical solutions:

[0005] A device for quantitatively measuring the cementing quality of a second cementing surface is improved in that it comprises a metal grooved tube housing, within which are enclosed an upper connector, an upper transmitting transducer, an upper sound insulator, a first receiving transducer, a second receiving transducer, a third receiving transducer, a fourth receiving transducer, a fifth receiving transducer, a sixth receiving transducer, a lower sound insulator, a lower transmitting transducer, and a lower connector, which are connected in sequence. The spacing between adjacent receiving transducers is 0.5 ft., the distance from the upper transmitting transducer to the first receiving transducer is 3 ft., and the distance from the lower transmitting transducer to the sixth receiving transducer is 2.5 ft.

[0006] Furthermore, the upper transmitting transducer is installed in the upper transmitting corrugated sound window, and the upper transmitting sound window fixed ends are respectively installed at both ends of the upper transmitting corrugated sound window; the lower transmitting transducer is installed in the lower transmitting corrugated sound window, and the lower transmitting sound window fixed ends are respectively installed at both ends of the lower transmitting corrugated sound window.

[0007] Furthermore, the first to sixth receiving transducers are installed in the integrated receiving acoustic window, and receiving acoustic window fixing ends are respectively installed at both ends of the integrated receiving acoustic window.

[0008] Furthermore, the upper transmitting acoustic window fixing end, the lower transmitting acoustic window fixing end and the receiving acoustic window fixing end are all mounted on corresponding positions of the metal grooved tube through pins.

[0009] Furthermore, the polytetrafluoroethylene tube passes through the upper transmitting transformer, the upper transmitting acoustic window fixed end, the upper transmitting transducer, the receiving acoustic window fixed end, the first to sixth receiving transducers, the lower transmitting acoustic window fixed end, the lower transmitting transducer and the lower transmitting transformer in sequence, and the transmitting and receiving signal lines are led from the polytetrafluoroethylene tube to the interface of the upper and lower joints.

[0010] Furthermore, silicone oil is circulated into the metal grooved tube.

[0011] A method for quantitatively measuring the cementing quality of the second cementation surface, using the above-mentioned device, is improved in that it includes the following steps:

[0012] Step 1: Extract formation wave train information:

[0013] When the transmitting transducer excites the acoustic wave signal, the wave trains received by the first to sixth receiving transducers are W and 1，1 (t), W 1，2 (t), W 1，3 (t), W 1，4 (t), W 1，5 (t), W 1，6 (t); When the transmitting transducer excites the acoustic wave signal, the wave trains received by the first to sixth receiving transducers are W 2，1 (t), W 2，2 (t), W 2，3(t), W 2，4 (t), W 2，5 (t), W 2，6 (t), by performing differential processing on these two sets of data, the formation wave can be extracted:

[0014]

[0015] In the above formula, i ranges from 1 to 6, ω represents the angular frequency, k represents the wave number, x represents the distance along the transmission direction, and S 1，i (ω, k) and S 2，i (ω, k) represent the wave train W 1，i (t) and W 2，i (t) The corresponding function in the frequency-wavenumber domain, W i (t) represents the wave train data obtained after the two sets of wave trains are transformed by frequency domain difference;

[0016] Step 2, calculation of the second interface bonding index:

[0017] Assume that the formation wave finally obtained by formula (1) is W(t), and calculate the formation wave energy E over a period of time:

[0018]

[0019] The attenuation rate α of the formation wave is determined by the mud content:

[0020]

[0021] In the above formula, V sh is the mud content of the target layer; V sh，max、 V sh，min are the maximum and minimum mud contents in the well, respectively;

[0022] The second interface bonding index BI2 is:

[0023]

[0024] In the above formula, E max is the formation wave energy with the maximum attenuation when the cementation is good, E min It is the formation wave energy with the least attenuation when the bonding is good.

[0025] Furthermore, when the upper transmitting transducer excites an acoustic wave signal, the first receiving transducer receives a signal corresponding to CBL, and the fifth receiving transducer receives a signal corresponding to VDL; when the lower transmitting transducer excites an acoustic wave signal, the fifth receiving transducer receives a signal corresponding to CBL, and the first receiving transducer receives a signal corresponding to VDL.

[0026] The beneficial effects of the utility model are:

[0027] The device disclosed in this utility model utilizes an integrated receiving acoustic window to encapsulate six sets of receiving transducers. This reduces the number of fixed ends required for the receiving windows, reducing the direct acoustic wave at the connection points while also ensuring a wide incident acoustic field for each set of receiving transducers. Addressing the weak link of acoustic wave transmission, an alternating top-end and bottom-end transmission method is employed to ensure a high logging success rate and prevent failures due to environmental influences.

[0028] The method disclosed by the present utility model uses differential algorithm processing of acoustic wave data transmitted and received twice alternately to suppress casing waves, thereby distinguishing formation wave train information, determining the cementation index of the second interface according to the energy of the formation wave, and realizing quantitative measurement of the cementing quality of the second cementation surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the device disclosed in the utility model;

[0030] Figure 2 It is a schematic diagram of the internal structure of the device disclosed in the utility model;

[0031] Figure 3 This is the effect diagram of extracting formation waves using the dual-transmitter-receiver differential method.

[0032] Figure numerals: 1-upper connector, 2-upper transmitting transducer, 3-upper sound insulator, 4-first receiving transducer, 5-second receiving transducer, 6-third receiving transducer, 7-fourth receiving transducer, 8-fifth receiving transducer, 9-sixth receiving transducer, 10-lower sound insulator, 11-lower transmitting transducer, 12-lower connector, 21-upper transmitting transformer, 22-upper transmitting acoustic window fixing end, 23-upper transmitting corrugated acoustic window, 25-receiving acoustic window fixing end, 26-receiving integrated acoustic window, 213-polytetrafluoroethylene tube, 214-lower transmitting acoustic window fixing end, 215-lower transmitting corrugated acoustic window, 217-lower transmitting transformer. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0034] Example 1: This embodiment discloses a device for quantitatively measuring the cementing quality of the second cementing surface, comprising a metal grooved tube housing, in which a piezoelectric transducer, a connecting wire, and necessary auxiliary structures are encapsulated, such as Figure 1As shown, the device includes an upper connector 1, an upper transmitting transducer 2, an upper sound insulator 3, a first receiving transducer 4, a second receiving transducer 5, a third receiving transducer 6, a fourth receiving transducer 7, a fifth receiving transducer 8, a sixth receiving transducer 9, a lower sound insulator 10, a lower transmitting transducer 11, and a lower connector 12, which are connected in sequence. The spacing between adjacent receiving transducers is 0.5 ft, the distance from the upper transmitting transducer to the first receiving transducer is 3 ft, and the distance from the lower transmitting transducer to the sixth receiving transducer is 2.5 ft.

[0035] The upper and lower connectors are used to connect electronic circuits. The sound emission and reception of this device are controlled by electronic circuits. The upper transmitting transducer and the lower transmitting transducer generate sound wave signals. The first to sixth receiving transducers receive the sound wave signals at the same time. The upper and lower sound insulators attenuate the direct wave signals.

[0036] During operation, the system alternates between up and down transmission. In the up-transmission mode, the signal received by the first receiving transducer corresponds to the CBL, and the signal received by the fifth receiving transducer corresponds to the VDL. In the down-transmission mode, the signal received by the fifth receiving transducer corresponds to the CBL, and the signal received by the first receiving transducer corresponds to the VDL. A set of CBL and VDL data can be selected as logging data. A differential algorithm is applied to the acoustic wave data from the two alternating transmissions and receptions to suppress casing waves. This allows the identification of wave trains corresponding to the formation wave time period. The cementation index of the second interface is determined based on the energy of the formation waves, enabling quantitative measurement of the cementing quality of the second cementation surface.

[0037] like Figure 2 As shown, the upper transmitting transducer 2 is installed in the upper transmitting corrugated acoustic window 23, and the upper transmitting acoustic window fixed ends 22 are respectively installed at both ends of the upper transmitting corrugated acoustic window; the lower transmitting transducer is installed in the lower transmitting corrugated acoustic window 215, and the lower transmitting acoustic window fixed ends 214 are respectively installed at both ends of the lower transmitting corrugated acoustic window.

[0038] The first to sixth receiving transducers are installed in the integrated receiving acoustic window 26 , and receiving acoustic window fixing ends 25 are respectively installed at both ends of the integrated receiving acoustic window.

[0039] The upper transmitting acoustic window fixing end, the lower transmitting acoustic window fixing end and the receiving acoustic window fixing end are all mounted on corresponding positions of the metal grooved tube through pins.

[0040] The polytetrafluoroethylene tube 213 passes through the upper transmitting transformer 21, the upper transmitting acoustic window fixed end 22, the upper transmitting transducer 2, the receiving acoustic window fixed end 25, the first to sixth receiving transducers 4-9, the lower transmitting acoustic window fixed end 214, the lower transmitting transducer 11 and the lower transmitting transformer 217 in sequence, and the transmitting and receiving signal lines are led from the polytetrafluoroethylene tube to the interface of the upper and lower joints.

[0041] Finally, silicone oil is circulated into the metal groove tube to ensure that the gas is discharged.

[0042] This embodiment also discloses a method for quantitatively measuring the cementing quality of the second cementing surface, using the above-mentioned device, comprising the following steps:

[0043] Step 1: Extract formation wave train information:

[0044] When the transmitting transducer excites the acoustic wave signal, the wave trains received by the first to sixth receiving transducers are W and 1，1 (t), W 1，2 (t), W 1，3 (t), W 1，4 (t), W 1，5 (t), W 1，6 (t); When the transmitting transducer excites the acoustic wave signal, the wave trains received by the first to sixth receiving transducers are W 2，1 (t), W 2，2 (t), W 2，3 (t), W 2，4 (t), W 2，5 (t), W 2，6 (t), for casing wave, wave train W 1，1 (t), W 1，2 (t), W 1，3 (t), W 1，4 (t), W 1，5 (t), W 1，6 (t) and wave train W 2，1 (t), W 2，2 (t), W 2，3 (t), W 2，4 (t), W 2，5 (t), W 2，6 (t) is correlated. By performing differential processing on these two sets of data, the casing wave is suppressed and the formation wave is extracted:

[0045]

[0046] In the above formula, i ranges from 1 to 6, ω represents the angular frequency, k represents the wave number, x represents the distance along the transmission direction, and S 1，i (ω, k) and S 2，i (ω, k) represent the wave train W 1，i (t) corresponds to W2,i(t) in the frequency-wavenumber domain, W i (t) represents the wave train data obtained after the two sets of wave trains are transformed by frequency domain difference. The effect is as follows: Figure 3 shown.

[0047] Step 2, calculation of the second interface bonding index:

[0048] Assume that the formation wave finally obtained by formula (1) is W(t), and calculate the formation wave energy E over a period of time:

[0049]

[0050] The attenuation characteristics of formation waves are related to the mud content of the formation. That is, the higher the mud content, the greater the formation's sound attenuation and the weaker the formation waves become. The mud content of the formation can be determined by the natural gamma curve. The attenuation rate of formation waves is determined by the mud content. α :

[0051]

[0052] In the above formula, V sh is the mud content of the target layer; V sh，max 、V sh，min are the maximum and minimum mud contents in the well, respectively;

[0053] When the formation acoustic attenuation α is known, the second interface bonding index BI2 is:

[0054]

[0055] In the above formula, E is the target layer formation wave energy, E max is the formation wave energy with the maximum attenuation when the cementation is good, E min is the formation wave energy with the minimum attenuation when the cementation is good, and α is the formation wave attenuation rate of the target layer.

[0056] Previously, when analyzing second-interface data, the quality of each measurement section was typically described verbally, which resulted in variability among different people. Now, formulas are used instead to achieve quantitative evaluation. For example, a higher second-interface cementation index (B12) indicates better cementing quality, thus enabling quantitative evaluation of the second cementation surface.

[0057] When the upper transmitting transducer excites an acoustic wave signal, the first receiving transducer receives a signal corresponding to the CBL, and the fifth receiving transducer receives a signal corresponding to the VDL. When the lower transmitting transducer excites an acoustic wave signal, the fifth receiving transducer receives a signal corresponding to the CBL, and the first receiving transducer receives a signal corresponding to the VDL. All signals received by the first through sixth receiving transducers are also used for formation wave extraction.

Claims

1. A device for quantitatively measuring the cementing quality of the second cementing surface, characterized by: The device comprises a grooved metal tube housing, wherein an upper connector, an upper transmitting transducer, an upper sound insulator, a first receiving transducer, a second receiving transducer, a third receiving transducer, a fourth receiving transducer, a fifth receiving transducer, a sixth receiving transducer, a lower sound insulator, a lower transmitting transducer, and a lower connector are enclosed in the grooved metal tube. Adjacent receiving transducers are spaced 0.5 ft apart, the distance from the upper transmitting transducer to the first receiving transducer is 3 ft, and the distance from the lower transmitting transducer to the sixth receiving transducer is 2.5 ft.

2. The device for quantitatively measuring the cementing quality of the second cementing surface according to claim 1, characterized in that: The upper transmitting transducer is installed in the upper transmitting corrugated sound window, and the upper transmitting sound window fixed ends are respectively installed at both ends of the upper transmitting corrugated sound window; the lower transmitting transducer is installed in the lower transmitting corrugated sound window, and the lower transmitting sound window fixed ends are respectively installed at both ends of the lower transmitting corrugated sound window.

3. The device for quantitatively measuring the cementing quality of the second cementing surface according to claim 2, characterized in that: The first to sixth receiving transducers are installed in the receiving integrated sound window, and receiving sound window fixing ends are respectively installed at both ends of the receiving integrated sound window.

4. The device for quantitatively measuring the cementing quality of the second cementing surface according to claim 3, characterized in that: The upper transmitting acoustic window fixing end, the lower transmitting acoustic window fixing end and the receiving acoustic window fixing end are all mounted on corresponding positions of the metal grooved tube through pins.

5. The device for quantitatively measuring the cementing quality of the second cementing surface according to claim 3, characterized in that: The polytetrafluoroethylene tube passes through the upper transmitting transformer, the upper transmitting acoustic window fixed end, the upper transmitting transducer, the receiving acoustic window fixed end, the first to sixth receiving transducers, the lower transmitting acoustic window fixed end, the lower transmitting transducer and the lower transmitting transformer in sequence, and the transmitting and receiving signal lines are led from the polytetrafluoroethylene tube to the interface of the upper and lower joints.

6. The device for quantitatively measuring the cementing quality of the second cementing surface according to claim 1, characterized in that: Silicone oil is circulated into the metal grooved tube.

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