CN115522914A - Radial long-distance high-precision detection method and system for cased reservoir - Google Patents
Radial long-distance high-precision detection method and system for cased reservoir Download PDFInfo
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Abstract
The invention relates to a radial long-distance high-precision detection method and a system for a cased reservoir, which comprises the following steps: analyzing a joint detection mechanism of an electromagnetic induction method and a linear source method, and establishing a jacketed reservoir joint detection layered columnar model combining electromagnetic induction and a linear source; designing the excitation of an electromagnetic probe and a line source based on the jacketed reservoir joint detection layered columnar model, and acquiring the radial remote detection results of the jacketed reservoir at different detection depths; and imaging the obtained radial remote detection results of the reservoir layer after casing at different detection depths to obtain the water injection burst front and the oil-water interface distribution condition. According to the invention, the reservoir resistivity is explained in a mode of combining electromagnetic induction and a line source, so that the limitation in reservoir detection in the prior art is eliminated, the reliability of inversion explanation of a reservoir detection system is improved, and a new idea is provided for on-line identification of a reservoir medium and oil-water interface area after an underground casing is sleeved. Therefore, the method can be widely applied to the technical field of oil reservoir detection.
Description
Technical Field
The invention relates to a radial long-distance high-precision detection method and system for a jacketed reservoir by combining electromagnetic induction with a line source, and belongs to the technical field of oil reservoir detection.
Background
In the process of oil exploitation, the problems of flooding, water injection layer collapse or well wall collapse and the like of oil layers in different degrees can occur due to a large amount of water injection, so that the recovery efficiency is seriously influenced. Therefore, for the cased well in the later stage of production, it is necessary to grasp the information of the reservoir outside the casing, especially the oil-water distribution and water injection breakthrough front edge, to perform accurate interpretation and evaluation, so as to provide theoretical guidance for further development of the reservoir, thereby increasing the oil production efficiency and reducing the oil production cost.
At present, a plurality of technologies have been developed at home and abroad to monitor the reservoir after the reservoir is set, and the introduction is as follows:
the tracer method is the method which is firstly applied to dynamic monitoring of a post-casing reservoir and needs to inject fluid containing a tracer, and the direction, speed and direction of water injection propulsion are determined by analyzing the arrival time and concentration of the tracer in water samples of various production wells in the whole test area. Then sampling is carried out on surrounding production wells according to a certain sampling rule, and the production condition and the heterogeneity of the reservoir stratum are monitored.
The seismic monitoring method is mainly used for monitoring the gas flooding front in the gas injection process so as to analyze the displacement effect and the influence of the displacement effect on a reservoir stratum.
The potential measurement method supplies high-power current to the underground through a sleeve, establishes a stable artificial electric field in the reservoir and realizes reservoir monitoring by measuring the change condition of the surface potential. Because of the huge resistivity difference among the residual oil, injected liquid and reservoir surrounding rocks of the detected target body, the resistivity difference can show strong repulsion or attraction to the surrounding leakage current path, so that an electric field artificially established in a detected range is distorted, and if the distortion field reaches the strength enough to reach the earth surface, the underground oil and gas distribution area and the water body coverage area can be inverted by observing the change of the ground potential around the well, thereby realizing the dynamic monitoring of the underground reservoir.
The electromagnetic monitoring among wells is acquired by continuously moving a high-power electromagnetic transmitter in one well and statically placing a series of receivers from top to bottom in the other well. Under excitation of a low frequency signal, a magnetic or electric dipole transmitter coil transmits an electromagnetic field into the formation. The eddy currents induced by the primary field in turn generate a secondary alternating field whose strength is inversely proportional to the formation resistivity. The primary and secondary alternating fields are detected at the receiver array.
The radioactive logging is a main means for logging the production well at present, and by testing partial elements and corresponding contents in the stratum, a mobile layer and a non-mobile layer can be determined, the residual oil distribution of the block can be known, a fluid interface can be detected, the porosity can be obtained, and the method is an indispensable means for re-knowing the stratum near the borehole.
The through-casing resistivity logging technology for a single well starts late, and at present, the feasible resistivity logging technology mainly comprises a leakage current method, a transient electromagnetic method and a line source method. The principles of the methods are different, and the common difficulty is how to correct the influence of the heterogeneity of the casing, the cement sheath and the stratum on the measurement result of the resistivity of the casing.
Although the method for testing the resistivity of the reservoir after the completion of the test has certain effect, the method also has some defects in the application process. The tracer method has the defects of complex testing process, long testing period, lagged testing result and the like; seismic methods are difficult to adapt to the monitoring of injected water because the injected water and formation water have substantially the same effect on the acoustic waves. Therefore, the seismic reservoir monitoring is mainly used for monitoring the gas flooding effect, and the displacement front edge is determined by comparing the attenuation of the time delay wave amplitude before and after gas injection; the potentiometric method requires the whole test to be carried out in stages, namely, the background potential is tested before water (gas) injection, then the potential is measured in stages in the injection process, dynamic monitoring on the reservoir stratum to be researched is realized through the change rule of the test potential in different stages, similar to the seismic method, the potentiometric method requires the whole test to be carried out in stages, namely, the background potential is tested before water (gas) injection, then the potential is measured in stages in the injection process, and therefore, the potentiometric method is difficult to adapt to the monitoring of injected water; the specific measurement parameters of the interwell electromagnetic measurement system are related to factors such as well spacing, transmitter and receiving intervals, casing type, working frequency and noise, and at present, the practical technology is very limited; in the single-well measurement method, the relatively feasible resistivity logging technology mainly comprises a leakage current method and a transient electromagnetic method. The two methods have different principles, and the common difficulty is how to correct the influence of the heterogeneity of the casing, the cement sheath and the stratum on the measurement result of the resistivity of the casing. The leakage current method mainly improves the accuracy of an interpretation result by researching a complex interpretation method, and the research difficulty is great; the transient electromagnetic method adopts non-contact electromagnetic induction, does not need focusing and can continuously measure, but is easily influenced by casing breakage, perforation and the like, so that the formed magnetic field is relatively disordered, and the influence is more obvious particularly for remote detection; the line source method, although detecting farther away, has lower resolution for near reservoirs.
Disclosure of Invention
In view of the above problems, the present invention aims to provide a method and a system for detecting the radial long-distance high-precision of a jacketed reservoir by combining electromagnetic induction with a line source, wherein the reservoir resistivity is explained by combining electromagnetic induction with the line source, so that the monitoring accuracy of the jacketed reservoir resistivity can be further improved.
In order to realize the purpose, the invention adopts the following technical scheme:
in a first aspect, the invention provides a method for detecting a post-casing reservoir radially, remotely and accurately, which comprises the following steps:
analyzing a joint detection mechanism of an electromagnetic induction method and a linear source method, and establishing a jacketed reservoir joint detection layered columnar model combining electromagnetic induction and a linear source;
designing the excitation of an electromagnetic probe and a line source based on the jacketed reservoir joint detection layered columnar model, and acquiring the radial remote detection results of the jacketed reservoir at different detection depths;
and imaging the obtained radial remote detection results of the reservoir layer after casing at different detection depths to obtain the water injection burst front and the oil-water interface distribution condition.
Further, the jacketed reservoir joint detection layered columnar model comprises a sleeve, a cement sheath and a reservoir which are sequentially arranged from inside to outside; the electromagnetic induction module comprises a magnetic core, and an array electromagnetic transmitting coil and an array electromagnetic receiving coil which are wound on the outer wall of the magnetic core, wherein the array electromagnetic transmitting coil is used for applying a bipolar step signal, and the array electromagnetic receiving coil is used for acquiring a secondary field signal; the inner wall of the sleeve is provided with a line source detection module, the line source detection module comprises an excitation electrode, a grounding electrode and an array measuring electrode, the excitation electrode is used for applying alternating current, and the array measuring electrode is used for measuring electric field response along the direction of the stratum.
Further, the method for designing the excitation of the electromagnetic probe and the line source based on the jacketed reservoir joint detection layered columnar model and obtaining the radial remote detection result of the jacketed reservoir at different detection depths comprises the following steps:
2.1 After obtaining the sleeveMedium radius r = r of a certain exploration depth of reservoir 1 ,r 2 ,…,r t ,r t+1 8230and making the radius of medium r = r 1 ,r 2 ,…,r t The near zone of the sleeve is used as a near zone, r = r t ,r t+1 \8230thedistal reservoir region of the cannula serves as the distal region;
2.2 Electromagnetic probe and line source excitation are designed based on the jacketed reservoir joint detection layered columnar model, the near zone resistivity is obtained by adopting an electromagnetic method, and the far zone resistivity is obtained by adopting a line source method;
2.3 Searching an interface of the near zone resistivity and the far zone resistivity, and splicing the monitoring results of the near zone resistivity and the far zone resistivity to obtain a radial remote detection result of the reservoir after the detection depth is set;
2.4 And) repeating the steps 2.1) and 2.3), and imaging based on the obtained radial remote detection results of the cased reservoir at different detection depths to obtain a water injection breakthrough front and an oil-water interface distribution condition.
Further, the method for obtaining the near zone resistivity by adopting the electromagnetic method comprises the following steps:
setting a transmitting mode of an array transmitting coil of the electromagnetic induction module, so that a transmitting magnetic field of the electromagnetic induction module is focused on a set detection depth;
determining a weight vector corresponding to the array electromagnetic receiving coil according to different transmitting and receiving distances;
and calculating the time domain induced electromotive force of a single electromagnetic receiving coil, and weighting the induced electromotive forces of all the electromagnetic receiving coils based on the corresponding weight vectors to obtain the average resistivity of the reservoir at different medium radiuses under the exploration depth.
Further, the time domain induced electromotive force of the single electromagnetic receiving coil is as follows:
wherein t represents an observation time, z n The receiving and transmitting distance of the nth receiving coil is represented; rho n Is the n-th connectionThe reservoir resistivity corresponding to the observation position of the coil is collected; p represents the order of the inverse laplace transform of G-S, and Dp represents the integral coefficient of the inverse laplace transform of G-S.
Further, the method for obtaining the far-zone resistivity by adopting a line source method comprises the following steps:
calculating theoretical potential values at different medium radiuses;
and (4) subtracting the theoretical potential values obtained by calculation at different medium radiuses from the corresponding measured potential values to obtain residual potential values, and calculating to obtain residual resistivity based on the residual potential values at different medium radiuses.
Further, the residual resistivity is:
in the formula, W is a coefficient of the post-set reservoir monitoring device based on a line source, and Δ V is a residual potential value.
In a second aspect, the present invention provides a radial remote high-precision detection system for a cased reservoir, comprising:
the model establishing module is used for analyzing a joint detection mechanism of an electromagnetic induction method and a linear source method and establishing a post-casing reservoir joint detection layered columnar detection model combining electromagnetic induction and a linear source;
the reservoir interpretation module is used for designing the excitation of the electromagnetic probe and the line source based on the jacketed reservoir joint detection layered columnar detection model and acquiring the radial remote detection results of the jacketed reservoirs at different detection depths;
and the result display module is used for imaging the obtained radial remote detection results of the reservoir layer after casing at different detection depths to obtain the water injection breakthrough front and the oil-water interface distribution condition.
In a third aspect, the present invention provides a processing apparatus comprising at least a processor and a memory, the memory having stored thereon a computer program, the processor executing the computer program to perform the steps of the method for high-precision detection of a cased reservoir radially and remotely.
In a fourth aspect, the present invention provides a computer storage medium having computer readable instructions stored thereon which are executable by a processor to perform the steps of the method for high-precision detection of a radial distance from a cased reservoir.
Due to the adoption of the technical scheme, the invention has the following advantages:
1. the invention combines the electromagnetic induction method with the line source method for the first time, can measure the near-zone resistivity outside the sleeve, can also measure the reservoir resistivity in the far zone, and can realize the remote reservoir monitoring outside the sleeve by combining the far zone and the near zone;
2. the electromagnetic induction probe adopts a multi-emission-multi-reception mode, a plurality of emissions can be used for realizing emission magnetic field focusing, a plurality of receptions can be used for array weighting, the problems of low line source short-distance measurement resolution and weak electromagnetic induction long-distance measurement signal strength can be solved, and the radial long-distance high-precision inversion interpretation of the sleeved reservoir can be realized.
In conclusion, the method can further improve the accuracy of the cased reservoir resistivity monitoring system, explains the reservoir resistivity in a mode of combining electromagnetic induction and a line source, eliminates the limitation in reservoir detection in the prior art, more importantly improves the inversion explanation reliability of the reservoir detection system, and provides a new idea for online identification of the reservoir medium and oil-water interface area after downhole casing. Therefore, the method can be widely applied to the technical field of oil reservoir detection.
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Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Like reference numerals refer to like parts throughout the drawings. In the drawings:
FIG. 1 is a flow chart of a method for detecting a radial remote high-precision reservoir after casing according to an embodiment of the invention;
FIG. 2 is a detection model of electromagnetic induction combined with a line source provided by an embodiment of the present invention;
FIG. 3 is a flowchart of the united interpretation of electromagnetic line sources provided by the embodiment of the invention;
fig. 4 is a monitoring data processing flow based on an electromagnetic induction method according to an embodiment of the present invention;
FIG. 5 is a schematic diagram and model of line source detection provided by an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the description of the embodiments of the invention given above, are within the scope of protection of the invention.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
In some embodiments of the invention, a method for detecting the radial long-distance high-precision of a sleeved reservoir by combining electromagnetic induction and a line source is disclosed, wherein the resistivity of the reservoir near a sleeve is firstly measured by using the electromagnetic induction, but because an electromagnetic receiving signal is an exponential signal attenuated along with time, a late signal is usually weak, and even if the late signal contains far reservoir information, effective test information is difficult to extract; aiming at the problem, a line source detection mode is adopted to measure remote medium information outside the sleeve, the sleeve body is used as a line current source, and oil-water distribution characteristics in an underground reservoir are obtained by measuring underground potential distribution; and finally, performing combined interpretation on the near-zone resistivity measured by electromagnetic induction and the far-zone resistivity measured by a line source method, solving the problems of low resolution of near-distance measurement of a line source and weak strength of electromagnetic induction remote measurement signals, and realizing radial remote high-precision inversion interpretation of the jacketed reservoir.
Correspondingly, the invention provides a radial long-distance high-precision detection system of the cased reservoir, which combines electromagnetic induction and a line source.
Example 1
As shown in fig. 1, the present embodiment provides a method for detecting a cased reservoir radially, remotely and highly accurately, which includes the following steps:
1) Analyzing a joint detection mechanism of an electromagnetic induction method and a linear source method, and establishing a jacketed reservoir joint detection layered columnar model combining electromagnetic induction and a linear source;
2) Designing the excitation of an electromagnetic probe and a line source based on the jacketed reservoir joint detection layered columnar model, and acquiring the radial remote detection results of the jacketed reservoir at different detection depths;
3) And imaging the obtained radial remote detection results of the reservoir layer after casing at different detection depths to obtain the water injection burst front and the oil-water interface distribution condition.
Preferably, in step 1), as shown in fig. 2, the post-casing reservoir joint detection layered columnar model includes a casing, a cement sheath and a reservoir which are sequentially arranged from inside to outside. The electromagnetic induction module comprises a magnetic core, an array electromagnetic transmitting coil and an array electromagnetic receiving coil, wherein the array electromagnetic transmitting coil and the array electromagnetic receiving coil are wound on the outer wall of the magnetic core; the inner wall of the sleeve is provided with a line source detection module, the line source detection module comprises an excitation electrode, a grounding electrode and an array measuring electrode, the excitation electrode is used for applying alternating current, and the array measuring electrode is used for measuring the electric field response along the direction of the stratum.
In the embodiment, in the electromagnetic induction module, because the secondary field signal shows an exponential decay trend along with the time change and contains a large amount of information related to the medium outside the casing, the related physical parameters of the reservoir outside the casing can be explained by analyzing the secondary field signal; in the line source detection module, when alternating current is applied to the transmitting sleeve (namely an exciting electrode) through a cable, electromagnetic waves are transmitted through a uniform stratum according to the electromagnetic induction principle, and the electric field response along the stratum direction is measured through the array measuring electrode. Because the measured electric field signal contains rich information of the outer storage layer, the purpose of reservoir detection can be achieved by analyzing the measured electric potential.
Preferably, in step 2), as shown in fig. 3, the method for obtaining the radial remote detection result of the cased reservoir at different detection depths comprises the following steps:
2.1 A radius of the medium at a certain exploration depth of the reservoir after casing is obtained.
Wherein, the radius of different media is related to the detected medium information of the reservoir section, and can be expressed as r = r from the inner layer to the outer layer in sequence 1 ,r 2 ,…,r t ,r t+1 8230r = r in the present embodiment 1 ,r 2 ,…,r t The zone is used as a near reservoir of the casing, namely a near zone, r = r t ,r t+1 Region as a reservoir remote from the casing, the remote zone.
2.2 Electromagnetic probe and line source excitation are designed based on the jacketed reservoir joint detection layered column model, the near zone resistivity is obtained by adopting an electromagnetic method, and the far zone resistivity is obtained by adopting a line source method.
2.3 Searching an interface of the near zone resistivity and the far zone resistivity, and splicing the monitoring results of the near zone resistivity and the far zone resistivity to obtain a radial remote detection result of the reservoir after the casing at the detection depth.
2.4 And) repeating the step 2.1) to the step 2.3), and imaging based on the obtained radial remote detection results of the cased reservoir at different detection depths to obtain the water injection breakthrough front and the distribution condition of the oil-water interface.
Preferably, in the step 2.2), the electromagnetic method for obtaining the near zone resistivity means that the near reservoir of the casing is obtained according to the electromagnetic method, that is, the radius of the medium is r 1 ,r 2 ,…,r t The average resistivity of the zonal reservoirs is taken as the near zone resistivity. Due to the electromagnetic coilThe receiving response of the sensor is a curve which exponentially decays along the change of time, the time of electromagnetic eddy current diffusion corresponds to different radiuses of a reservoir, and signals at different observation times correspond to medium information of the reservoir at different radiuses, so that r can be determined according to the signal change corresponding to different observation times t 。
As shown in fig. 4, the method comprises the following steps:
2.2.1 Setting a transmitting mode of an array transmitting coil of the electromagnetic induction module to enable a transmitting magnetic field of the electromagnetic induction module to be focused on a set detection depth so as to improve longitudinal monitoring resolution;
2.2.2 According to the difference of the receiving and transmitting distances, determining a weight vector corresponding to the array electromagnetic receiving coil, namely array weighting, so as to improve the monitoring signal-to-noise ratio;
2.2.3 The induced electromotive force of a single electromagnetic receiving coil is calculated, and the induced electromotive forces of all the electromagnetic receiving coils are weighted based on the corresponding weight vectors to obtain the average resistivity of the reservoir at different medium radiuses under the exploration depth.
Preferably, in the step 2.2.3), the method for calculating the induced electromotive force of the single electromagnetic receiving coil includes:
first, the frequency domain induced electromotive force of the nth electromagnetic receiving coil is calculated, which can be expressed as:
wherein, f (λ, r, ω, ρ) n ) And xi is a variable related to the measured medium information, and is a constant variable expressed as:
f(λ,r,ω,ρ n )＝x 1 C 1 I 0 (x 1 r) (2)
ξ＝μ 1 N R N T I T /π (3)
where ω is the angular frequency, z n For a transmission/reception distance, p n The resistivity of the reservoir corresponding to the observation position of the nth receiving coil, i is an imaginary number unit, r 1 Is the radius of the transmitting coil, mu 1 For transmitting coil magnetic conductanceThe ratio, r, is the radius of the measured medium outside the sleeve, x 1 And λ are all introduced variables, C 1 To undetermined coefficient, I 0 () Modifying Bessel function for order 0 of the first kind, N T And N R The number of turns of the electromagnetic transmitting coil and the electromagnetic receiving coil, I T Is the emission current.
Second, assume that the off-time of the ramp step signal is t of Then, the equation (1) can be converted into the time domain by using the P-th order G-S inverse laplace transform, and the time domain induced electromotive force of the nth electromagnetic receiving coil can be obtained as follows:
wherein i ω = pln2/t, t and D p Integral coefficients, z, representing the observation time and the inverse Laplace transform of G-S, respectively n The receiving and transmitting distance of the nth receiving coil is represented; rho n The reservoir resistivity corresponding to the observation position of the nth receiving coil; p is the order of the inverse Laplace transform of G-S, and Dp is the integral coefficient of the inverse Laplace transform of G-S.
Preferably, in the step 2.2), the obtaining of the far zone resistivity by using the line source method refers to obtaining the far reservoir of the casing according to the line source method, that is, the radius of the medium is r t ,r t+1 8230the zonal resistivity of the reservoir is taken as the far zone resistivity.
As shown in fig. 5, a simplified diagram of a line source detection module. Since the casing diameter is much smaller than the casing length, the casing can be handled as an inline current source. For a single measuring electrode, the measured potential value mainly consists of two parts, namely, a uniform electric field with a main status is formed around the cased well, and the electric field is distributed in a cylindrical symmetrical shape and can be calculated according to the electric field basic theory; and secondly, the electric field distribution abnormality caused by the heterogeneity of the resistivity of the oil layer is specifically represented by the repulsion of the high-resistance region to the current line and the attraction of the low-resistance region to the current line, which can cause the abnormality of potential measurement.
2.2.1 The theoretical potential values at each medium radius were calculated.
The theoretical potential value V is decomposed into the sum of a normal field (background field) potential value Vn and an abnormal value Va, that is
V＝Vn+Va (5)
Wherein, the normal field potential value Vn can be calculated according to the normal value of the vertical line current source in the half-space medium, namely:
where ρ is the average resistivity of the monitored region, I L For supplying current,/ L Is the length of the line source, s is the radial distance from the measuring electrode to the line source, and d is the depth at which the measuring electrode is located.
The abnormal potential Va can be obtained numerically, for example, by constructing a sparse system of linear equations, i.e.
HVa＝Q (7)
In the formula, H is a sparse matrix, and Q is a residual potential vector, which are known quantities.
2.2.2 The theoretical potential values and the measured potential values obtained by calculation at different medium radiuses are subtracted to obtain residual potential values, and residual resistivity, namely the far zone resistivity, is obtained by calculation based on the residual potential values at different medium radiuses.
Wherein, according to the relation between the potential and the resistivity, the residual potential value Δ V can be converted into residual resistivity Δ ρ, which includes:
wherein W is the coefficient of the post-casing reservoir monitoring device based on the line source.
Example 2
The embodiment 1 provides a method for detecting a cased reservoir radially remotely with high accuracy, and correspondingly, the embodiment provides a system for detecting a cased reservoir radially remotely with high accuracy. The system provided by this embodiment can implement the method for detecting a radially remote high-precision reservoir in the set back of embodiment 1, and the system can be implemented by software, hardware or a combination of software and hardware. For example, the system may comprise integrated or separate functional modules or functional units to perform the corresponding steps in the methods of embodiment 1. Since the system of this embodiment is substantially similar to the method embodiment, the description process of this embodiment is relatively simple, and reference may be made to part of the description of embodiment 1 for relevant points.
The radial remote high-precision detection system of the cased reservoir provided by the embodiment comprises:
the model establishing module is used for analyzing a joint detection mechanism of an electromagnetic induction method and a linear source method and establishing a jacketed reservoir joint detection layered columnar detection model combining electromagnetic induction and a linear source;
the reservoir interpretation module is used for designing the excitation of the electromagnetic probe and the line source based on the jacketed reservoir joint detection layered columnar detection model and acquiring the radial remote detection results of the jacketed reservoirs at different detection depths;
and the result display module is used for imaging the obtained radial remote detection results of the reservoir layer after casing at different detection depths to obtain the water injection breakthrough front and the oil-water interface distribution condition.
Example 3
This embodiment provides a processing device corresponding to the method for detecting a radially remote high-precision cased reservoir in embodiment 1, where the processing device may be a processing device for a client, such as a mobile phone, a laptop, a tablet, a desktop, etc., to execute the method in embodiment 1.
The processing equipment comprises a processor, a memory, a communication interface and a bus, wherein the processor, the memory and the communication interface are connected through the bus so as to complete mutual communication. The memory stores a computer program which can be run on the processor, and the processor executes the computer program to execute the method for detecting the radial long-distance high-precision of the cased reservoir provided by the embodiment 1.
In some embodiments, the Memory may be a Random Access Memory (RAM), and may also include a non-volatile Memory (non-volatile Memory), such as at least one disk Memory.
In other embodiments, the processor may be any type of general-purpose processor such as a Central Processing Unit (CPU), a Digital Signal Processor (DSP), and the like, and is not limited herein.
Example 4
The method for detecting a radial long-distance high-precision of a cased reservoir according to this embodiment 1 may be embodied as a computer program product, which may include a computer readable storage medium having computer readable program instructions for executing the method for detecting a radial long-distance high-precision of a cased reservoir according to this embodiment 1.
The computer readable storage medium may be a tangible device that retains and stores instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any combination of the foregoing.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A radial long-distance high-precision detection method for a cased reservoir is characterized by comprising the following steps:
analyzing a joint detection mechanism of an electromagnetic induction method and a linear source method, and establishing a jacketed reservoir joint detection layered columnar model combining electromagnetic induction and a linear source;
designing the excitation of an electromagnetic probe and a line source based on the jacketed reservoir joint detection layered cylindrical model, and acquiring the radial remote detection results of the jacketed reservoirs at different detection depths;
and imaging the obtained radial remote detection results of the reservoir layer after casing at different detection depths to obtain the water injection burst front and the oil-water interface distribution condition.
2. The method for remotely detecting the high precision of the radial direction of the cased reservoir as claimed in claim 1, wherein the cased reservoir joint detection layered columnar model comprises a casing, a cement sheath and a reservoir which are arranged from inside to outside in sequence; the electromagnetic induction module comprises a magnetic core, and an array electromagnetic transmitting coil and an array electromagnetic receiving coil which are wound on the outer wall of the magnetic core, wherein the array electromagnetic transmitting coil is used for applying a bipolar step signal, and the array electromagnetic receiving coil is used for acquiring a secondary field signal; the inner wall of the sleeve is provided with a line source detection module, the line source detection module comprises an excitation electrode, a grounding electrode and an array measuring electrode, the excitation electrode is used for applying alternating current, and the array measuring electrode is used for measuring the electric field response along the direction of the stratum.
3. The method for radial remote high-precision detection of the cased reservoir as claimed in claim 1, wherein the method for designing the excitation of the electromagnetic probe and the line source based on the cased reservoir joint detection layered column model and obtaining the radial remote detection results of the cased reservoir at different detection depths comprises the following steps:
2.1 ) obtain the medium radius r = r of a certain exploration depth of the reservoir after casing 1 ,r 2 ,…,r t ,r t+1 8230and making the radius of medium r = r 1 ,r 2 ,…,r t The near reservoir region of the casing of (1) is used as the near zone, r = r t ,r t+1 8230a distal reservoir region of the cannula as a distal region;
2.2 Electromagnetic probe and line source excitation are designed based on the jacketed reservoir joint detection layered columnar model, the near zone resistivity is obtained by adopting an electromagnetic method, and the far zone resistivity is obtained by adopting a line source method;
2.3 Searching an interface of the near zone resistivity and the far zone resistivity, and splicing the monitoring results of the near zone resistivity and the far zone resistivity to obtain a radial remote detection result of the reservoir after the detection depth is set;
2.4 And) repeating the step 2.1) to the step 2.3), and imaging based on the obtained radial remote detection results of the cased reservoir at different detection depths to obtain the water injection breakthrough front and the distribution condition of the oil-water interface.
4. A method for remotely detecting high-precision radial direction of a cased reservoir as claimed in claim 3, wherein said method for obtaining near zone resistivity by electromagnetic method comprises:
setting a transmitting mode of an array transmitting coil of the electromagnetic induction module to enable a transmitting magnetic field of the electromagnetic induction module to be focused on a set detection depth;
determining a weight vector corresponding to the array electromagnetic receiving coil according to different transmitting and receiving distances;
and calculating the time domain induced electromotive force of a single electromagnetic receiving coil, and weighting the induced electromotive forces of all the electromagnetic receiving coils based on the corresponding weight vector to obtain the average resistivity of the reservoir at different medium radiuses under the exploration depth.
5. A radial long-distance high-precision detection method for a cased reservoir as claimed in claim 4, wherein the time-domain induced electromotive force of said single electromagnetic receiving coil is:
wherein t represents an observation time, z n The receiving and transmitting distance of the nth receiving coil is represented; rho n The reservoir resistivity corresponding to the observation position of the nth receiving coil; p represents the order of the inverse laplace transform of G-S, and Dp represents the integral coefficient of the inverse laplace transform of G-S.
6. A method for remotely detecting high accuracy in the radial direction of a cased reservoir as claimed in claim 3, wherein said obtaining the resistivity of the remote zone by using a line source method comprises:
calculating theoretical potential values at different medium radiuses;
and (4) subtracting the theoretical potential values obtained by calculation at different medium radiuses from the corresponding measured potential values to obtain residual potential values, and calculating to obtain residual resistivity based on the residual potential values at different medium radiuses.
7. A method for remotely detecting a radial distance of a post casing reservoir with high accuracy as claimed in claim 3, wherein said residual resistivity is:
in the formula, W is a coefficient of the post-set reservoir monitoring device based on a line source, and Δ V is a residual potential value.
8. A radial remote high-precision detection system for a cased reservoir, comprising:
the model establishing module is used for analyzing a joint detection mechanism of an electromagnetic induction method and a linear source method and establishing a post-casing reservoir joint detection layered columnar detection model combining electromagnetic induction and a linear source;
the reservoir interpretation module is used for designing the excitation of the electromagnetic probe and the line source based on the jacketed reservoir joint detection layered columnar detection model and acquiring the radial remote detection results of the jacketed reservoirs at different detection depths;
and the result display module is used for imaging the obtained radial remote detection results of the reservoir layer after casing at different detection depths to obtain the water injection breakthrough front and the oil-water interface distribution condition.
9. A processing apparatus comprising at least a processor and a memory, the memory having stored thereon a computer program, wherein the processor when executing the computer program performs the steps of implementing a method for highly accurate detection of a cased reservoir radial distance as claimed in any one of claims 1 to 7.
10. A computer storage medium having computer readable instructions stored thereon which are executable by a processor to perform the steps of a method for remotely and highly accurately probing a cased reservoir radially according to any of claims 1 to 7.
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| CN116878614A (en) * | 2023-06-11 | 2023-10-13 | 中国地质大学（武汉） | Vortex loss differential array type oil-water interface detection system and method |
| CN116878614B (en) * | 2023-06-11 | 2024-03-22 | 中国地质大学（武汉） | Vortex loss differential array type oil-water interface detection system and method |
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