阅读说明：本技术 套内外物质阻抗计算、关系确定、固井评价方法和设备 (Method and equipment for calculating impedance of substances inside and outside sleeve, determining relation and evaluating well cementation ) 是由 陶爱华 王文梁 程林波 王明辉 张勇 李疾翎 孙志峰 梁国武 陈雪莲 谢景平 刘 于 2019-11-08 设计创作，主要内容包括：本发明实施例提供了一种套内外物质阻抗计算方法、套管内外物质阻抗与兰姆波衰减关系确定方法、套管内外物质阻抗与共振波共振效率关系确定方法、固井质量评价方法和计算机设备。所述套内外物质阻抗计算方法包括：设置兰姆波测量设备与共振波测量设备指向套管内同一位置,获得兰姆波衰减测量值与共振波共振效率测量值；根据所述兰姆波衰减测量值和预先确定的套管内外物质阻抗与兰姆波衰减的第一函数关系,以及根据所述共振波共振效率测量值和预先确定的套管内外物质阻抗与共振效率的第二函数关系,计算获得套管内外物质的阻抗值。本发明实施例方案提高了对套后物质阻抗反演的精准度,并能同时计算套管内流体物质的声阻抗。(The embodiment of the invention provides a method for calculating the impedance of substances inside and outside a casing, a method for determining the impedance of the substances inside and outside the casing and lamb wave attenuation relation, a method for determining the impedance of the substances inside and outside the casing and resonance efficiency relation of resonance waves, a method for evaluating well cementation quality and computer equipment. The method for calculating the impedance of the substances inside and outside the sleeve comprises the following steps: setting lamb wave measuring equipment and resonance wave measuring equipment to point to the same position in the sleeve to obtain a lamb wave attenuation measured value and a resonance wave resonance efficiency measured value; and calculating to obtain the impedance values of the substances inside and outside the casing according to the lamb wave attenuation measured value and a predetermined first functional relation between the impedance of the substances inside and outside the casing and the lamb wave attenuation and according to the resonance wave resonance efficiency measured value and a predetermined second functional relation between the impedance of the substances inside and outside the casing and the resonance efficiency. According to the embodiment of the invention, the inversion accuracy of the impedance of the sleeved substance is improved, and the acoustic impedance of the fluid substance in the sleeve can be calculated at the same time.)

1. A method for calculating the impedance of substances inside and outside a casing is characterized by comprising the following steps:

setting lamb wave measuring equipment and resonance wave measuring equipment to point to the same position in the sleeve to obtain a lamb wave attenuation measured value and a resonance wave resonance efficiency measured value;

and calculating to obtain the impedance values of the substances inside and outside the casing according to the lamb wave attenuation measured value and a predetermined first functional relation between the impedance of the substances inside and outside the casing and the lamb wave attenuation and according to the resonance wave resonance efficiency measured value and a predetermined second functional relation between the impedance of the substances inside and outside the casing and the resonance efficiency.

2. The method of claim 1,

the calculating and obtaining the impedance values of the substances inside and outside the casing according to the lamb wave attenuation measured value and a predetermined first functional relation between the impedance of the substances inside and outside the casing and the lamb wave attenuation and according to the resonance wave resonance efficiency measured value and a predetermined second functional relation between the impedance of the substances inside and outside the casing and the resonance efficiency comprises the following steps:

and according to the fact that the impedance of the substances in the casing in the first functional relation is the same as the impedance of the substances in the casing in the second functional relation, combining the lamb wave attenuation measured value, the resonance wave resonance efficiency measured value, the first functional relation and the second functional relation to perform inversion calculation to obtain the impedance of the substances inside and outside the casing.

3. The method of claim 2,

the method further comprises the following steps: setting lamb wave measuring equipment and resonance wave measuring equipment to scan at least a plurality of positions to obtain a plurality of lamb wave attenuation measured values and a plurality of resonance wave resonance efficiency measured values;

and the combined lamb wave attenuation measurement value, the resonance wave resonance efficiency measurement value, the first functional relationship and the second functional relationship are subjected to inversion calculation to obtain the impedance of the substances inside and outside the casing, and the method comprises the following steps:

for each position, combining a lamb wave attenuation measured value, a resonance wave resonance efficiency measured value, the first functional relation and the second functional relation to perform inversion calculation to obtain the impedance of the substances inside and outside the casing pipe, and calculating the impedance of the substances inside and outside the casing pipe at the ith position by using the impedance of the substances inside and outside the casing pipe at a plurality of positions around the ith position after obtaining the impedance of the substances inside and outside the casing pipe at the plurality of positions; or

And performing inversion calculation by combining the lamb wave attenuation measured values at a plurality of positions around the ith position, the resonance wave resonance efficiency measured values at a plurality of positions around the ith position, the first functional relationship and the second functional relationship to obtain the impedance of the substances inside and outside the casing at the ith position.

4. The method according to claim 2 or 3,

and the combined lamb wave attenuation measurement value, the resonance wave resonance efficiency measurement value, the first functional relationship and the second functional relationship are subjected to inversion calculation to obtain the impedance of the substances inside and outside the casing, and the method comprises the following steps:

traversing the impedance combination of the substances inside and outside the casing in the value range of the impedance of the substances inside the casing and the value range of the impedance of the substances outside the casing, so that the difference between the lamb wave attenuation value obtained by the impedance combination of the substances inside and outside the casing and the first functional relation and the lamb wave attenuation measured value is within a first preset difference value range, and simultaneously, the difference between the resonance wave resonance efficiency value obtained by the impedance combination of the substances inside and outside the casing and the second functional relation and the resonance wave resonance efficiency measured value is within a second preset difference value range.

5. The method of claim 3,

the obtaining of the impedance of the material inside and outside the casing at the ith position by combining the lamb wave attenuation measured values at a plurality of positions around the ith position, the resonance wave resonance efficiency measured values at a plurality of positions around the ith position, the first functional relationship and the second functional relationship through inversion calculation comprises:

traversing the impedance combination of the substances inside and outside the casing in the value range of the impedance of the substances inside the casing and the value range of the impedance of the substances outside the casing, and calculating 2n +1 f_mTake f_mThe impedance of the intra-cannula substance and the impedance of the extra-cannula substance at the minimum are taken as the impedance of the intra-cannula substance and the impedance of the extra-cannula substance at the i-th position:

wherein m is in the value range of [ i-n, i + n]，n∈[0，2]Zin ranges, for example, [0.1,3 ]]Zout ranges, for example, from [0.1,10 ]]，Att_mRepresenting the measured value of lamb wave attenuation at the m-th position, F₁() Is said first functional relationship, b_mRepresenting the measured value of the resonance efficiency of the resonance wave at the m-th position, F₂() Is a second functional relationship.

6. The method of claim 1,

the first functional relation is:

Att＝coef1*Zout+coef2*Zin+K

where Zout is the impedance of the material outside the casing, coef1 and coef2 are constants determined by the casing thickness, Zin is the impedance of the material inside the casing, Att is the lamb wave attenuation measurement, and K is the instrument constant.

7. The method of claim 1,

the second functional relation is:

Zout＝Zin_{reference to}-C*H*Ln(b/(P*Zin+Q)*B_{Reference to})

Wherein Zout is the impedance value of the material outside the casing, Zin_{Reference to}For the impedance value of the reference material in the casing for resonance wave measurement, C, P, Q is a constant coefficient, H is the casing wall thickness, B is the measurement of resonance wave resonance efficiency, Zin is the impedance value of the material in the casing, B is the impedance value of the material in the casing_{Reference to}The resonant efficiency of the resonance wave is measured when the reference material is inside and outside the casing.

8. The method of claim 7,

zin when the reference substance is water_{Reference to}＝1.5，C＝0.555，P＝0.3724，Q＝0.446。

9. A method for determining the relation between the impedance of substances inside and outside a casing and lamb wave attenuation is characterized by comprising the following steps:

measuring lamb wave measurements of the casing using a measuring device under different environmental conditions including one or more of: the thickness of the sleeve, the substances in the sleeve and the substances outside the sleeve;

and obtaining a first functional relation between the impedance of substances inside and outside the casing and lamb wave attenuation according to inversion of the lamb wave measured value: zuult ═ f₁(Zinl, Att, H), wherein Zoutl represents the impedance value of the external material of the casing when lamb waves are measured, Zinl represents the impedance value of the internal material of the casing when lamb waves are measured, Att represents the attenuation of lamb waves when they propagate in the casing, and H represents the wall thickness of the casing.

10. The method of claim 9, wherein the inverted first functional relationship between the in-and-out-of-casing material impedance and lamb wave attenuation is:

Att＝coef1*Zoutl+coef2*Zinl+K

in the formula, Zoutl is the impedance value of the substances outside the casing during lamb wave measurement, coef1 and coef2 are constants determined by the thickness of the casing, Zinl is the impedance value of the substances inside the casing during lamb wave measurement, Att is the attenuation measurement value of lamb wave, and K is the instrument constant.

11. A method for determining the relation between the impedance of substances inside and outside a sleeve and the resonance efficiency of a resonant wave is characterized by comprising the following steps:

measuring resonant wave resonance efficiency measurements of the casing at different environmental conditions using a measuring device, the environmental conditions including one or more of: the thickness of the sleeve, the substances in the sleeve and the substances outside the sleeve;

and obtaining a second functional relation between the impedance of the substances inside and outside the sleeve and the resonance efficiency of the resonance wave according to inversion of the resonance efficiency measured value of the resonance wave: zuutg ═ f₂(Zing, b, H), wherein Zoutg represents an impedance value of the off-casing material at the time of resonance wave measurement, Zing is an impedance value of the in-casing material at the time of resonance wave measurement, b is a resonance efficiency measurement of the resonance wave, and H is a casing thickness.

12. The method of claim 11, wherein the inverted second functional relationship between the impedance of the material inside and outside the casing and the resonance efficiency of the resonant wave is as follows:

Zoutg＝Zin_{reference to}-C*H*Ln(b/(P*Zing+Q)*B_{Reference to})

Wherein Zoutg is the impedance value of the substance outside the casing pipe when measuring the resonance wave, Zin_{Reference to}C, P, Q is a constant coefficient, H is the wall thickness of the casing, B is the measured value of resonance efficiency of the resonance wave, Zing is the impedance value of the material in the casing when the resonance wave is measured, B is the impedance value of the reference material in the casing when the resonance wave is measured, B_{Reference to}The resonant efficiency of the resonance wave is measured when the reference material is inside and outside the casing.

13. A well cementation quality evaluation method is characterized in that an impedance value of substances outside a casing is obtained through calculation by the method of any one of claims 1 to 7, the quality of well cementation is determined to be qualified if the impedance value of the substances outside the casing is larger than a first threshold value, the quality of well cementation is determined to be unqualified if the impedance value of the substances outside the casing is smaller than a second threshold value, and the second threshold value is smaller than or equal to the first threshold value.

14. A computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the steps of the method of any one of claims 1-8, or 9-10, or 11-12, or 13 are implemented when the program is executed by the processor.

Technical Field

The invention relates to the field of cased well cementing quality detection, in particular to methods and equipment for calculating impedance of internal and external substances, determining a relation and evaluating cementing.

Background

In the field of cementing quality detection of cased wells, a plurality of measuring instruments are provided, and acoustic wave instruments are main instruments, such as: early sonic amplitude, medium amplitude variable density logging tool (CBL-VDL), recent sector cementing logging tool (SBT). The more advanced well cementation quality detection instruments comprise: the MuIL of the Schlumberger USI ultrasonic imaging logging instrument, the Harinbington CAST logging instrument and the multifunctional ultrasonic imaging instrument of the Zhonghai oilfield service company Limited utilizes pulse echoes to calculate the acoustic impedance value after sleeving, and the state of the medium (substance) after sleeving is judged according to the acoustic impedance value so as to evaluate the well cementation quality.

The medium and early acoustic wave instrument requires that the material in the casing well is water, mud in the well has great influence on measurement, and serious deviation can occur if the existing technology for processing water environment measurement data is used for processing mud well measurement data.

Disclosure of Invention

The embodiment of the invention provides a method for calculating the impedance of substances inside and outside a casing, a method for determining the attenuation relation between the impedance of the substances inside and outside the casing and lamb waves, a method for determining the resonance efficiency relation between the impedance of the substances inside and outside the casing and resonance waves, a well cementation quality evaluation method and computer equipment, which can solve the problem that the impedance of the substances after the casing cannot be quantitatively calculated by sound wave data when the impedance of the substances inside the casing is uncertain.

In one aspect, an embodiment of the present invention provides a method for calculating impedance of substances inside and outside a casing, including:

setting lamb wave measuring equipment and resonance wave measuring equipment to point to the same position in the sleeve to obtain a lamb wave attenuation measured value and a resonance wave resonance efficiency measured value;

and calculating to obtain the impedance values of the substances inside and outside the casing according to the lamb wave attenuation measured value and a predetermined first functional relation between the impedance of the substances inside and outside the casing and the lamb wave attenuation and according to the resonance wave resonance efficiency measured value and a predetermined second functional relation between the impedance of the substances inside and outside the casing and the resonance efficiency.

On the other hand, the embodiment of the invention also provides a method for determining the relation between the impedance of substances inside and outside the casing and lamb wave attenuation, which comprises the following steps:

measuring lamb wave measurements of the casing using a measuring device under different environmental conditions including one or more of: the thickness of the sleeve, the substances in the sleeve and the substances outside the sleeve;

and obtaining a first functional relation between the impedance of substances inside and outside the casing and lamb wave attenuation according to inversion of the lamb wave measured value: zuult ═ f₁(Zinl, Att, H), wherein Zoutl represents the impedance value of the material outside the casing when measuring lamb waves, Zinl represents the impedance value of the material inside the casing when measuring lamb waves, Att represents the attenuation of lamb waves when propagating in the casing, and H represents the casing wall thickness。

On the other hand, the embodiment of the invention also provides a method for determining the relation between the impedance of substances inside and outside the sleeve and the resonance efficiency of the resonant wave, which comprises the following steps:

measuring resonant wave resonance efficiency measurements of the casing at different environmental conditions using a measuring device, the environmental conditions including one or more of: the thickness of the sleeve, the substances in the sleeve and the substances outside the sleeve;

and obtaining a second functional relation between the impedance of the substances inside and outside the sleeve and the resonance efficiency of the resonance wave according to inversion of the resonance efficiency measured value of the resonance wave: zuutg ═ f₂(Zing, b, H), wherein Zoutg represents an impedance value of the off-casing material at the time of resonance wave measurement, Zing is an impedance value of the in-casing material at the time of resonance wave measurement, b is a resonance efficiency measurement of the resonance wave, and H is a casing thickness.

On the other hand, the embodiment of the invention also provides a well cementation quality evaluation method, wherein the method is adopted to calculate and obtain the impedance value of the substances outside the casing, the quality of the well cementation is determined to be qualified if the impedance value of the substances outside the casing is judged to be larger than a first threshold value, and the quality of the well cementation is determined to be unqualified if the impedance value of the substances outside the casing is judged to be smaller than a second threshold value which is smaller than or equal to the first threshold value.

In yet another aspect, an embodiment of the present invention further provides a computer device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor executes the computer program to implement the foregoing steps of the method.

In the embodiment of the invention, an ultrasonic lamb wave instrument is utilized to generate lamb waves in a sleeve, the relation between the attenuation value and the impedance of substances inside and outside the sleeve is established, and the ultrasonic lamb wave instrument is utilized to measure the resonance efficiency of a resonance mode; through experimental measurement and theoretical calculation, on the basis of a measurement value of a scale ultrasonic lamb wave instrument, the impedance of substances inside and outside the sleeve is solved by combining a relational expression of attenuation and the impedance of the substances inside and outside the sleeve and a relational expression of resonance efficiency and the impedance of the substances inside and outside the sleeve, and then the gas-liquid-solid state of the substances is judged. The method for jointly solving the substances inside and outside the casing solves the problem that the impedance of the substances after the casing cannot be quantitatively calculated by well cementation sound wave data when the impedance of liquid in the casing is uncertain. Actual measurement test results show that the new calculation method improves the inversion accuracy of the impedance of the substances after the casing, and can calculate the acoustic impedance of the fluid medium in the casing at the same time. Compared with the prior calculation method, the new method has the advantages that the impedance error of the substances after the casing is calculated is reduced by more than 20 percent, and the accuracy of well cementation quality evaluation is improved.

Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the application. Other advantages of the application may be realized and attained by the instrumentalities and combinations particularly pointed out in the specification, claims, and drawings.

Drawings

The accompanying drawings are included to provide an understanding of the present disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the examples serve to explain the principles of the disclosure and not to limit the disclosure.

FIG. 1a is a top view of an experimental measurement environment;

FIG. 1b is a cross-sectional view of an experimental measurement environment;

FIG. 2a shows the well fluid at 1.2g/cm in four casing thicknesses³A simulation calculation result graph of the impedance Zout of the substances outside the casing and the lamb wave attenuation rate during the oil-based mud;

FIG. 2b is a graph of the results of experimental measurements of the attenuation rate of a casing of four thicknesses when the borehole fluid is water, as a function of the impedance of the material outside the casing;

FIG. 3a is a graph showing the relationship between the attenuation rate of bending lamb waves and the acoustic impedance Zin of the mud in the well when the substance outside the casing is water and the oil-based mud is in the well respectively;

FIG. 3b is a graph showing the relationship between the attenuation ratio of bending lamb waves and the acoustic impedance Zin of the mud in the well when the substance outside the casing is water and the mud in the well is water-based mud respectively;

FIG. 4 is a schematic diagram of the method for solving the impedance of the material inside and outside the casing by using the resonance wave and the lamb wave in combination according to the embodiment of the invention;

FIG. 5 is a flowchart of a method for calculating impedance of substances inside and outside a casing according to an embodiment of the present invention;

FIG. 6 is a flow chart of a well cementation quality evaluation method according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a computer device for implementing the method for calculating the impedance of the substances inside and outside the casing.

Detailed Description

The present application describes embodiments, but the description is illustrative rather than limiting and it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are possible. Any feature or element of any embodiment may be used in combination with or instead of any other feature or element in any other embodiment, unless expressly limited otherwise.

The present application includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features and elements disclosed in this application may also be combined with any conventional features or elements to form a unique inventive concept as defined by the claims. Any feature or element of any embodiment may also be combined with features or elements from other inventive aspects to form yet another unique inventive aspect, as defined by the claims. Thus, it should be understood that any of the features shown and/or discussed in this application may be implemented alone or in any suitable combination. Accordingly, the embodiments are not limited except as by the appended claims and their equivalents. Furthermore, various modifications and changes may be made within the scope of the appended claims.

Further, in describing representative embodiments, the specification may have presented the method and/or process as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. Other orders of steps are possible as will be understood by those of ordinary skill in the art. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. Further, the claims directed to the method and/or process should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the embodiments of the present application.

The basic principle of measuring the well cementation quality by an ultrasonic logging instrument is that the acoustic impedance of substances outside a sleeve corresponds to a measured echo signal. At present, when the impedance of fluid in a well is changed, an ultrasonic logging instrument has no formula for calculating the impedance after sleeving in a targeted manner. The acoustic impedance Z is equal to the product of the acoustic longitudinal wave velocity of the material and the material density. Speed unit mm/us, density unit g/cm³Impedance units MRayl. Under the dimension, the impedance of the gas is close to 0MRayl, the impedance of the water is equal to 1.5MRayl, the impedance of the well cementation cement is related to the density and the sound velocity of the cement, and the density of the commonly used well cementation cement is 1.0-2 g/cm³The sound velocity is 1800-3700m/s, so the impedance range is 2.8-8 MRayl. Some schemes for calculating the external acoustic impedance of the casing need to find a free casing well section in the casing well as reference, and a reference value is manually input to calculate the acoustic impedance of substances outside the casing, so that the method has large error.

The existing calculation formula for calculating the impedance after casing is shown as formula (1), and the impedance of the material outside the casing at the reference point position of the cased hole and the resonance efficiency value at the position are required to be known.

Wherein Z is the impedance of the substance outside the cannula, Z₀The impedance of the foreign matter at the reference point, H is the thickness of the cannula (in mm),

according to the formula, in the measurement well section of the cased well, if the reference point with known impedance of the substances outside the casing cannot be found, the impedance of the substances outside the casing of the well section to be measured cannot be calculated.

The applicant provides a method for calculating the impedance of substances inside and outside a casing without free casing calibration based on an ultrasonic lamb wave instrument through carrying out a large number of measurement experimental researches in mud with different densities. According to the method provided by the embodiment of the invention, a free casing well section does not need to be searched in a cased well for reference, the acoustic impedance of substances outside the casing is obtained through the combined solution of the resonance efficiency and the lamb wave attenuation measured by an ultrasonic lamb wave instrument, and meanwhile, the acoustic impedance of the substances inside the casing is obtained, and no manual intervention is needed in the process.

In order to jointly solve the impedance of substances inside and outside the casing, the relationship between the resonance efficiency and the impedance of the substances inside and outside the casing and the relationship between the lamb wave attenuation and the impedance of the substances inside and outside the casing need to be established through laboratory data. When the underground measurement is actually carried out, the impedance of the substances inside and outside the casing is solved according to the measured value of the instrument and the pre-established relation. The following are described separately.