Well cementation quality evaluation method and device based on microseism monitoring technology

Abstract

The invention provides a well cementation quality evaluation method and device based on a microseism monitoring technology. According to the method, the well cementation quality effect of each section of the horizontal well is effectively evaluated on the basis of microseism event waves and characteristics generated by the fact that liquid enters a stratum during fracturing construction to cause rock to slide along a weak plane. According to the technology, the difference of well cementation quality of each section is comprehensively evaluated based on dynamic parameters such as fracture energy, extension direction and extension characteristics of microseism monitoring in the fracturing construction period in combination with perforation signals and seismic attribute characteristics; the multi-parameter fusion technology effectively improves the accuracy of well cementation quality evaluation, provides an effective data basis for real-time adjustment of fracturing construction with poor well cementation quality, optimizes and adjusts the fracturing process, and improves the reservoir transformation effect.

Description

Technical Field

[0001] The present invention relates to the technical field of petroleum geophysical exploration, and more specifically, to a cementing quality assessment method and device based on microseismic monitoring technology. Background Art

[0002] Cementing is the engineering operation of inserting casing into the well and injecting cement into the annular space between the wellbore and the casing. It is an indispensable part of the drilling and completion process. The main purpose of cementing is to protect and support the casing in the oil and gas well and to isolate the oil, gas and water formations. The quality of cementing is the construction quality of the cementing operation. The best quality is when there is no gap between the well wall and the casing after cementing. The main indicators are the bonding between the cement and the formation, as well as the strength quality.

[0003] Whether horizontal well fracturing can successfully transform the reservoir in oil and gas field development depends on the quality of cementing. Cementing quality is directly related to the life of oil and gas wells, production capacity and the overall benefits of exploration and development. Good cementing quality can significantly improve the timeliness and benefits of development; unqualified cementing quality can cause fracturing fluid channeling during fracturing construction, resulting in sand and water production, formation collapse, and even oil pipe damage, which will not achieve the effect of reservoir transformation and stability. With the continuous deepening of fine development of oil fields, higher requirements are put forward for cementing quality assessment technology.

[0004] There are many existing methods for evaluating cementing, such as: acoustic variable density method, sector cement bonding method, well temperature method, isotope tracer method, etc. Each method has its own advantages and disadvantages. The use of gamma density and acoustic variable density logging methods to comprehensively analyze the cementing quality of oil and water wells can complement each other's shortcomings and solve the multi-solution problem in cementing quality monitoring. The comprehensive analysis of the two methods of sector cement bonding logging and acoustic gamma density logging can evaluate the cementing interface I and II, and can identify the local loss of cement ring greater than or equal to 45°, which is more accurate than the previous interpretation results.

[0005] At present, cost reduction and efficiency improvement have become important goals of oil and gas fields. Some production and development wells have not carried out cementing quality engineering testing during cementing. How to analyze and evaluate the impact of cementing quality during fracturing construction and development is also very important. With the development of distributed fiber optic sensing technology, the application effect of cementing quality assessment based on distributed fiber optic sensing technology in the field of full life cycle monitoring of development wells has become increasingly prominent; during cementing, permanent optical fiber is laid outside the casing; after the cementing operation is completed, the optical fiber continues to monitor the temperature and its changes of the entire well section outside the casing, the changes of liquid or gas flow noise, the formation stress and its changes, and the pressure and its changes of the fluid in the formation pores in real time, and judge and evaluate the quality, integrity and firmness of the high-pressure cement outside the casing in real time, and monitor the changes, breakage, interlayer cross-flow, deformation or damage of the high-pressure cement outside the casing after cementing in real time. However, this technology has high engineering construction costs and high technical requirements for engineering cementing, and has not been fully promoted and applied.

[0006] Therefore, there is an urgent need for a technical solution that can effectively evaluate the cementing quality. Summary of the invention

[0007] In view of this, the present invention discloses a cementing quality assessment method based on microseismic monitoring technology, which realizes cementing quality analysis and evaluation of fracturing wells during fracturing of development wells, and analyzes whether cementing quality is the main factor affecting fracturing effect.

[0008] According to one aspect of the present invention, a cementing quality assessment method based on microseismic monitoring technology is proposed, the method comprising:

[0009] Step 1: Analyze the characteristics of microseismic monitoring data of each section of perforation in the horizontal well, analyze the wave clarity, identifiability, and signal frequency of each section of perforation signal, and obtain analysis data;

[0010] Step 2: Based on the analysis data, calculate the moment magnitude M of each microseismic event corresponding to each cluster perforation. w ;

[0011] Step 3, performing energy compensation on each perforation signal;

[0012] Step 4, after energy compensation, analyze the differences in recognition rate, positioning accuracy, moment magnitude, and signal-to-noise ratio of each segment of perforation signal;

[0013] Step 5: According to the analysis results, a suspected abnormal perforation signal is selected from each section of the perforation signal, and the well section corresponding to the suspected abnormal perforation signal is identified as the abnormal operation section;

[0014] Step 6, counting the number, moment magnitude, and sweep direction of microseismic events in each segment, and analyzing the spatial position of microseismic event points in each segment;

[0015] Step 7, analyzing the temporal and spatial distribution morphological characteristics of microseismic events in each section during the fracturing operation;

[0016] Step 8, identifying suspected cementing quality abnormal sections from each section according to the temporal and spatial distribution morphological characteristics obtained by analysis;

[0017] Step 9, eliminating the well sections with abnormal microseismic distribution caused by natural fracture zones. Among the remaining well sections, if a well section is identified as a construction abnormality section and also identified as a suspected cementing quality abnormality section, then the well section is confirmed to be a cementing quality abnormality section;

[0018] Step 10: Based on the confirmation results, the cementing quality of the entire well section is evaluated.

[0019] In some embodiments, in step 2, the moment magnitude M is calculated according to the following formula: w :

[0020]

[0021]

[0022] Among them, ρ 0 is the density, v 0 is the wave velocity, R is the distance from the source to the seismic pickup, Ω 0 is the lowest frequency level of displacement, F c It is a radiation field type.

[0023] In some embodiments, step 5 specifically includes:

[0024] According to the analysis results, perforation signals with low signal-to-noise ratio, low recognition rate and abnormal wave field characteristics are identified as suspected abnormal perforation signals, and the well section corresponding to the suspected abnormal perforation signal is identified as the abnormal operation section.

[0025] In some implementations, step 8 specifically includes:

[0026] If the construction displacement is stable, with the continuous injection of fracturing fluid, microseismic event points appear evenly and extend vertically along both sides of the wellbore in this section, it can be identified that this section is not a suspected cementing quality abnormal section.

[0027] In some implementations, step 8 specifically includes:

[0028] If the construction displacement is stable and the fracturing fluid is continuously injected, the microseismic event point is asymmetric with the wellbore, and most of the microseismic event points between different fracturing sections overlap and are distributed linearly, it is judged that this section is affected by the natural fracture zone and is identified as not a suspected section with abnormal cementing quality.

[0029] In some implementations, step 8 specifically includes:

[0030] If, with the continuous injection of fracturing fluid, the overlapping microseismic event points between different fracturing sections exceed the preset ratio and are all distributed near the wellbore of the overlapping points, the section is identified as a suspected section with abnormal cementing quality.

[0031] In some implementations, step 8 specifically includes:

[0032] If the microseismic events occur across sections as the fracturing fluid is continuously injected, and extend vertically along both sides of the wellbore in this section as the fracturing progresses, showing a linear distribution, the section can be identified as a suspected section with abnormal cementing quality.

[0033] In some implementations, step 8 specifically includes:

[0034] If the microseismic events suddenly decrease with the continuous injection of fracturing fluid, the construction displacement is stable, there is no fracture development zone around this section, and the geological characteristics do not change much, this section is identified as a suspected section with abnormal cementing quality.

[0035] In some implementations, step 8 specifically includes:

[0036] Comprehensively analyze the spatiotemporal distribution morphological characteristics of microseismic event points and the moment magnitude of microseismic events. If a large moment magnitude occurs and the occurrence rate is concentrated, accompanied by a decrease in construction pressure, it is judged that the section is a hydraulic fracturing artificial fracture that has entered the natural fracture zone, and this section is identified as not a suspected cementing quality abnormality section.

[0037] According to another aspect of the present invention, a cementing quality assessment device based on microseismic monitoring technology is also proposed, and the method includes:

[0038] The raw data analysis unit is used to analyze the characteristics of microseismic monitoring data of each section of perforation in the horizontal well, analyze the wave clarity, identifiability, and signal frequency of each section of perforation signal, and obtain analysis data;

[0039] The moment magnitude calculation unit is used to calculate the moment magnitude M of each microseismic event corresponding to each cluster perforation according to the analysis data. w ;

[0040] Energy compensation unit, used to perform energy compensation on each perforation signal;

[0041] The perforation signal analysis unit is used to analyze the differences in recognition rate, positioning accuracy, moment magnitude, and signal-to-noise ratio of each segment of the perforation signal after energy compensation;

[0042] The abnormal operation section identification unit is used to select the suspected abnormal perforation signal from each section of the perforation signal according to the analysis result, and identify the well section corresponding to the suspected abnormal perforation signal as the abnormal operation section;

[0043] The microseismic event point spatial position analysis unit is used to count the number, moment magnitude, and sweep direction of microseismic events in each segment, and analyze the spatial position of microseismic event points in each segment;

[0044] The microseismic event spatiotemporal distribution analysis unit is used to analyze the spatiotemporal distribution morphological characteristics of microseismic events in each section during the fracturing operation;

[0045] A suspected cementing quality abnormal section identification unit is used to identify the suspected cementing quality abnormal section from each section according to the temporal and spatial distribution morphological characteristics obtained by analysis;

[0046] The cementing quality abnormal section confirmation unit is used to eliminate the well sections with abnormal microseismic distribution caused by natural fracture zones. Among the remaining well sections, if a well section is identified as a construction abnormal section and also identified as a suspected cementing quality abnormal section, then the well section is confirmed as a cementing quality abnormal section.

[0047] The whole-well section cementing quality evaluation unit is used to realize the cementing quality evaluation of the whole-well section according to the confirmation result.

[0048] In some embodiments, in the moment magnitude calculation unit, the moment magnitude M is calculated according to the following formula: w :

[0049]

[0050]

[0051] Among them, ρ 0 is the density, v 0 is the wave velocity, R is the distance from the source to the seismic pickup, Ω 0 is the lowest frequency level of displacement, F c It is a radiation field type.

[0052] In some implementations, the abnormal construction section identification unit is specifically used to:

[0053] According to the analysis results, perforation signals with low signal-to-noise ratio, low recognition rate and abnormal wave field characteristics are identified as suspected abnormal perforation signals, and the well section corresponding to the suspected abnormal perforation signal is identified as the abnormal operation section.

[0054] In some embodiments, the suspected cementing quality abnormal section identification unit includes:

[0055] The first identification subunit is used to identify the section as not suspected of cementing quality abnormality if the construction displacement is stable and the fracturing fluid is continuously injected, the microseismic event points appear evenly and extend vertically along both sides of the wellbore in this section.

[0056] In some embodiments, the suspected cementing quality abnormal section identification unit includes:

[0057] The second identification subunit is used to determine that if the construction displacement is stable and the fracturing fluid is continuously injected, the microseismic event point is asymmetric with the wellbore, and most of the microseismic event points between different fracturing sections overlap and are distributed linearly, the section is judged to be affected by the natural fracture zone, and the section is identified as not a suspected cementing quality abnormal section.

[0058] In some embodiments, the suspected cementing quality abnormal section identification unit includes:

[0059] The third identification subunit is used to identify the section as a suspected cementing quality abnormal section if the overlapping microseismic event points between different fracturing sections exceed a preset ratio and are all distributed near the overlapping points near the wellbore as the fracturing fluid is continuously injected.

[0060] In some embodiments, the suspected cementing quality abnormal section identification unit includes:

[0061] The fourth identification subunit is used to identify the section as a suspected abnormal cementing quality section if microseismic events occur across sections as the fracturing fluid is continuously injected and extend vertically along both sides of the wellbore in this section in a linear distribution as the fracturing progresses.

[0062] In some embodiments, the suspected cementing quality abnormal section identification unit includes:

[0063] The fifth identification subunit is used to identify the section as a suspected abnormal cementing quality section if the microseismic events suddenly decrease with the continuous injection of fracturing fluid, the construction displacement is stable, there are no fracture development zone characteristics around the section, and the geological characteristics do not change much.

[0064] In some embodiments, the suspected cementing quality abnormal section identification unit includes:

[0065] The fifth identification subunit is used to comprehensively analyze the spatiotemporal distribution morphological characteristics of microseismic event points and the moment magnitude of microseismic events. If a large moment magnitude occurs and the occurrence rate is concentrated, accompanied by a decrease in construction pressure, it is judged that the section is a hydraulic fracturing artificial fracture that has entered the natural fracture zone, and the section is identified as not a suspected cementing quality abnormality section.

[0066] According to another aspect of the present invention, an electronic device is also provided, the electronic device comprising:

[0067] A memory storing executable instructions;

[0068] A processor runs the executable instructions in the memory to implement the cementing quality assessment method based on microseismic monitoring technology as described above.

[0069] According to another aspect of the present invention, a computer-readable storage medium is provided, which stores a computer program. When the computer program is executed by a processor, the cementing quality assessment method based on microseismic monitoring technology described above is implemented.

[0070] The present invention is based on the characteristics of microseismic events caused by the sliding of rocks along weak surfaces caused by liquid entering the formation during fracturing construction, and effectively evaluates the cementing quality of each section of the horizontal well. This technology is based on dynamic parameters such as fracture energy, extension direction, and extension characteristics monitored by microseismic monitoring during fracturing construction, combined with perforation signals and seismic attribute characteristics, to comprehensively evaluate the differences in cementing quality of each section; multi-parameter fusion technology effectively improves the accuracy of cementing quality evaluation, and at the same time provides an effective data basis for real-time adjustment of fracturing construction with poor cementing quality, optimizes and adjusts the fracturing process, and improves the effect of reservoir transformation. The advantages of this technical solution are further explained in detail below.

[0071] 1. Improved the accuracy of cementing quality evaluation.

[0072] The present invention takes into account dynamic information such as rupture energy and extension direction through analysis and evaluation of microseismic multi-parameters, and the evaluation result is more accurate and comprehensive.

[0073] 2. It provides an optimization basis for on-site construction.

[0074] The present invention can evaluate cementing quality in real time, discover problematic well sections, and provide an effective reference for optimizing and adjusting the fracturing process on site.

[0075] 3. The scope of evaluation has been expanded.

[0076] The present invention does not carry out cementing quality detection in the well section, and the method can also be used to implement evaluation during the fracturing process, thereby expanding the scope of application.

[0077] 4. Reduced evaluation costs.

[0078] Compared with the traditional optical fiber monitoring method, the present invention uses the microseismic information during the fracturing process for evaluation, avoiding the high cost of laying additional optical fibers.

[0079] 5. Improved the reservoir transformation effect of oil and gas fields.

[0080] The evaluation results can provide a basis for subsequent improvement of cementing quality, reduce fracturing losses, better transform oil and gas reservoirs, and increase production capacity.

[0081] 6. Optimized the benefits of oil and gas development.

[0082] Accurate evaluation and improvement of cementing quality can extend the life of oil and gas wells and significantly improve the economic benefits of development.

[0083] The methods and apparatus of the present invention have other features and advantages that will be apparent from or will be described in detail in the accompanying drawings and subsequent detailed descriptions incorporated herein, which together serve to explain the specific principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0085] Figure 1 A flow chart of a cementing quality assessment method based on microseismic monitoring technology according to an embodiment of the present invention is shown.

[0086] Figure 2 A horizontal schematic diagram of the 9th and 10th microseismic events according to an exemplary embodiment of the present invention is shown.

[0087] Figure 3 A horizontal schematic diagram of microseismic events in sections 10, 11 and 12 according to an exemplary embodiment of the present invention is shown.

[0088] Figure 4 A horizontal schematic diagram of the 17th and 18th microseismic events according to an exemplary embodiment of the present invention is shown.

[0089] Figure 5 A horizontal schematic diagram of the 22nd and 23rd microseismic events according to an exemplary embodiment of the present invention is shown.

[0090] Figure 6 A schematic diagram of a microseismic monitoring profile of the third cluster of perforations in the 10th section according to an exemplary embodiment of the present invention is shown.

[0091] Figure 7 A conceptual schematic diagram of the technical solution of the present invention is shown. DETAILED DESCRIPTION

[0092] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0093] The concept of the present invention is briefly introduced below.

[0094] Figure 7 The schematic diagram of the concept of the present invention is shown. During the fracturing construction, liquid entering the formation will affect the stability of natural fractures, bedding, etc., causing rocks to slide along weak surfaces and generate "micro-earthquakes". During the fracturing of horizontal development wells in oil and gas fields, the present invention indirectly evaluates the cementing quality of each section of the horizontal well through various parameters such as the perforation effect of each section, the fracture energy, extension direction, and extension characteristics of the artificial fractures transformed in each reservoir based on micro-seismic monitoring technology, so as to realize the cementing quality analysis and evaluation of the fracturing well during the fracturing of the development well, and accurately identify whether the cementing quality is the main factor affecting the fracturing effect.

[0095] This technical solution conducts perforation data analysis and microseismic event analysis based on microseismic monitoring data and fracturing engineering seconds, and statistically analyzes the recognition rate, signal-to-noise ratio and moment magnitude of perforation signals, as well as the spatial and temporal characteristics and moment magnitude of microseismic events; then, based on the perforation data analysis results, the perforation signal is evaluated based on the recognition rate of perforation signals, wave field characteristic differences, etc., to find suspected abnormal perforation signals; analyzes the abnormal distribution of the spatial and temporal distribution morphological characteristics of microseismic events during fracturing construction, conducts cementing quality evaluation, and finds suspected cementing quality abnormal sections; then, based on the perforation signal evaluation, cementing quality evaluation, and natural fracture characteristics combined with seismic attribute data, completes the cementing quality evaluation of the entire well section.

[0096] Example 1

[0097] Figure 1 A flow chart of a cementing quality assessment method based on microseismic monitoring technology according to an embodiment of the present invention is shown. As shown in the figure, the method includes steps 1 to 10.

[0098] Step 1: Analyze the characteristics of microseismic monitoring data of each section of perforation in the horizontal well, analyze the wave clarity, identifiability, and frequency of the perforation signal of each section, and obtain analysis data.

[0099] The characteristics of microseismic monitoring data of each section of perforation can be analyzed from the dimensions of signal clarity, recognition effect, frequency characteristics, etc.

[0100] The clarity of the wave arrival can reflect the clarity and continuity of the hole signal. Clear and complete wave arrival is the basis for identification and analysis.

[0101] Identifiability is used to evaluate whether the perforation signal can be effectively identified in the background noise. The recognition rate directly affects the subsequent quantitative analysis.

[0102] Signal frequency characteristics mainly analyze the main frequency components of the signal. Frequency anomalies may reflect the formation conditions.

[0103] Through the analysis and evaluation of these dimensions, the quality and abnormal conditions of the perforation signal can be comprehensively judged, laying the foundation for subsequent quantitative measurement and qualitative analysis.

[0104] Step 2: Based on the analysis data, calculate the moment magnitude M of each microseismic event corresponding to each cluster perforation. w .

[0105] In some embodiments, the moment magnitude M may be calculated according to the following formula: w :

[0106]

[0107]

[0108] Among them, ρ 0 is the density, v 0 is the wave velocity, R is the distance from the source to the seismic pickup, Ω 0 is the lowest frequency level of displacement, F c is the radiation field type. For P waves, F c It can be 0.52; for S wave F c The value can be 0.63.

[0109] Moment magnitude is used to indicate the size of an earthquake. Compared with the Richter magnitude, moment magnitude can more objectively and accurately reflect the energy released by an earthquake.

[0110] The moment magnitude can reflect the total energy of fracture and sliding of formation rocks under the action of fracturing. The moment magnitude calculated according to the present invention can more accurately quantify the fracture situation of the formation, providing a basis for fracturing effect evaluation and cementing quality judgment.

[0111] Step 3: Perform energy compensation on the perforation signals of each segment.

[0112] Microseismic monitoring is greatly affected by anthropogenic noise. The difference in noise from anthropogenic activities during the day and night is large, which will affect signal acquisition. The low noise level at night is conducive to the identification of weak signals, while the high noise during the day has a shielding effect. In order to ensure the consistency and comparability of magnitude measurement, it is necessary to compensate for the effect of daytime noise enhancement.

[0113] The magnitude of the same signal will be calculated differently under different noise levels.

[0114] By normalizing the energy, the influence of noise is eliminated, and the microseismic signals observed at different time periods and / or at different noise levels are made comparable. Therefore, this embodiment performs energy compensation on the perforation signal to offset the influence of day and night, noise and other factors on the signal, improves the data quality through correction, reduces the negative influence of noise, and makes the microseismic analysis results more reliable.

[0115] Step 4: After energy compensation, analyze the differences in recognition rate, positioning accuracy, moment magnitude, and signal-to-noise ratio of each segment of perforation signal.

[0116] After energy compensation, the perforation signals of each section are compared from the perspective of recognition rate, positioning accuracy, moment magnitude and signal-to-noise ratio, so as to check the signal quality and identify the perforation signals with problems or abnormalities. The moment magnitude directly reflects the energy of rock fracture and the perforation effect. The recognition rate, positioning accuracy and signal-to-noise ratio comprehensively reflect the clarity and effectiveness of the signal itself.

[0117] Step 5: According to the analysis results, the suspected abnormal perforation signal is selected from the perforation signals of each section, and the well section corresponding to the suspected abnormal perforation signal is identified as the abnormal operation section.

[0118] In some embodiments, based on the analysis results, perforation signals with low signal-to-noise ratio, low recognition rate, and abnormal wave field characteristics can be identified as suspected abnormal perforation signals, and the well section corresponding to the suspected abnormal perforation signal can be identified as the abnormal construction section.

[0119] Perforation signals with low signal-to-noise ratio, low recognition rate and abnormal wave field characteristics can be identified as suspected abnormal perforation signals, in other words, the sections with the greatest problems and the worst quality.

[0120] Abnormal perforation signals often mean that there may be problems in the well section, so the well section corresponding to the suspected abnormal perforation signal is identified as the abnormal construction section.

[0121] Step 6: Count the number, moment magnitude, and direction of microseismic events in each segment, and analyze the spatial position of the microseismic event points in each segment.

[0122] The number of microseismic events, moment magnitude, and sweep direction of each segment are counted and analyzed. These indicators can comprehensively reflect the spatial distribution, rupture intensity, and extension trend of microseismic activities in the abnormal segment.

[0123] Analyzing the spatial distribution coordinates of each microseismic event in the abnormal section can be used to determine the situation near the wellbore and the main gathering area, providing an important basis for judging the cementing quality.

[0124] Step 7: Analyze the spatiotemporal distribution characteristics of microseismic events in each section during the fracturing operation.

[0125] The temporal and spatial distribution morphological characteristics mainly refer to the regularity of the spatial distribution of microseismic events as the fracturing operation progresses. It can reflect the expansion of microseismic events caused by the opening of natural fractures by fracturing fluid.

[0126] The spatiotemporal distribution morphological characteristics can be analyzed and judged mainly from the following aspects:

[0127] 1) Whether the spatial expansion trend of the microseismic event point is consistent with the wellbore trend;

[0128] 2) Whether the distribution shape of microseismic event points in space is symmetrical;

[0129] 3) Whether the spatial distribution of event points overlaps between different fracturing stages;

[0130] 4) Changes in microseismic activity during the fracturing stage and the pump shutdown stage.

[0131] By analyzing these characteristics, we can determine whether the cracks opened by fracturing are normal, evaluate the quality of cementing cement, and analyze the differences in cementing quality between sections, providing a basis for subsequent judgment of the quality of cementing.

[0132] Step 8: According to the temporal and spatial distribution morphological characteristics obtained by analysis, the suspected cementing quality abnormal sections are identified from each section.

[0133] In some implementations, step 8 specifically includes:

[0134] If the construction displacement is stable, with the continuous injection of fracturing fluid, microseismic event points appear evenly and extend vertically along both sides of the wellbore in this section, it can be identified that this section is not a suspected cementing quality abnormal section.

[0135] After research, the inventors believe that if the displacement is stable, with the continuous injection of fracturing fluid, the microseismic event points appear evenly and extend vertically along both sides of the wellbore in this section, then it can be considered as a section with relatively good cementing quality.

[0136] In some implementations, step 8 specifically includes:

[0137] If the construction displacement is stable and the fracturing fluid is continuously injected, the microseismic event point is asymmetric with the wellbore, and most of the microseismic event points between different fracturing sections overlap and are distributed linearly, it is judged that this section is affected by the natural fracture zone and is identified as not a suspected section with abnormal cementing quality.

[0138] After research, the inventors believe that if the displacement is stable and the fracturing fluid is continuously injected, the microseismic event points are asymmetric with the wellbore, and most of the microseismic event points between different fracturing sections overlap and are distributed linearly. Considering the influence of natural fracture zones, the correlation with cementing quality is not greatly affected.

[0139] In some implementations, step 8 specifically includes:

[0140] If, with the continuous injection of fracturing fluid, the overlapping microseismic event points between different fracturing sections exceed the preset ratio and are all distributed near the wellbore of the overlapping points, the section is identified as a suspected section with abnormal cementing quality.

[0141] After research, the inventors believe that with the continuous injection of fracturing fluid, most of the microseismic event points between different fracturing sections overlap and are distributed near the wellbore of the overlapping points. It is considered that the overlapping sections are affected by poor cementing quality.

[0142] In some implementations, step 8 specifically includes:

[0143] If the microseismic events occur across sections as the fracturing fluid is continuously injected, and extend vertically along both sides of the wellbore in this section as the fracturing progresses, showing a linear distribution, the section can be identified as a suspected section with abnormal cementing quality.

[0144] After research, the inventor believes that with the continuous injection of fracturing fluid, microseismic events occur across sections, and as fracturing progresses, they extend vertically along both sides of the wellbore in this section, showing a linear distribution. It is likely that this section is affected by poor cementing quality.

[0145] In some implementations, step 8 specifically includes:

[0146] If the microseismic events suddenly decrease with the continuous injection of fracturing fluid, the construction displacement is stable, there is no fracture development zone around this section, and the geological characteristics do not change much, this section is identified as a suspected section with abnormal cementing quality.

[0147] After research, the inventor believes that with the continuous injection of fracturing fluid, the microseismic events suddenly decreased, the construction displacement was stable, there was no crack development zone around this section, and the geological characteristics did not change much, so it is likely that there is an abnormality in the cementing quality of this section.

[0148] In some implementations, step 8 specifically includes:

[0149] Comprehensively analyze the spatiotemporal distribution morphological characteristics of microseismic event points and the moment magnitude of microseismic events. If a large moment magnitude occurs and the occurrence rate is concentrated, accompanied by a decrease in construction pressure, it is judged that the section is a hydraulic fracturing artificial fracture that has entered the natural fracture zone, and this section is identified as not a suspected cementing quality abnormality section.

[0150] After research, the inventor believes that a comprehensive analysis of the spatiotemporal distribution characteristics of microseismic points, sections with poor cementing quality, and moment magnitudes of microseismic events show that, if large moment magnitudes occur and the occurrence rate is relatively concentrated, accompanied by a decrease in construction pressure, it is considered that the artificial fractures transformed by hydraulic fracturing have entered the natural fracture zone. Analysis shows that the anomaly in this section is not related to the poor cementing quality.

[0151] Step 9, remove the well sections with abnormal microseismic distribution caused by natural fracture zones. Among the remaining well sections, if a well section is identified as a construction abnormality section and also identified as a suspected cementing quality abnormality section, then the well section is confirmed to be a cementing quality abnormality section.

[0152] After eliminating the abnormal distribution sections of microseismic events caused by natural fracture zones, and combining the perforation signals with the spatial and temporal distribution morphological characteristics of microseismic events for comprehensive analysis, if a well section is identified as both an abnormal construction section and an abnormal cementing quality section, both are abnormal, the inventors believe that it can be confirmed that the cementing quality of this section is abnormal.

[0153] Step 10: Based on the confirmation results, the cementing quality of the entire well section is evaluated.

[0154] This embodiment is based on the characteristics of microseismic events caused by the sliding of rocks along weak surfaces caused by the entry of liquid into the formation during fracturing construction, and effectively evaluates the cementing quality of each section of the horizontal well. This technology is based on the dynamic parameters such as fracture energy, extension direction, and extension characteristics of microseismic monitoring during fracturing construction, combined with perforation signals and seismic attribute characteristics, to comprehensively evaluate the differences in cementing quality of each section; multi-parameter fusion technology effectively improves the accuracy of cementing quality evaluation, and at the same time provides an effective data basis for real-time adjustment of fracturing construction with poor cementing quality, optimizes and adjusts the fracturing process, and improves the effect of reservoir transformation.

[0155] Example 2

[0156] According to one embodiment of the present invention, a cementing quality assessment device based on microseismic monitoring technology is provided, the device comprising:

[0157] The raw data analysis unit is used to analyze the characteristics of microseismic monitoring data of each section of perforation in the horizontal well, analyze the wave clarity, identifiability, and signal frequency of each section of perforation signal, and obtain analysis data;

[0158] The moment magnitude calculation unit is used to calculate the moment magnitude M of each microseismic event corresponding to each cluster perforation according to the analysis data. w ;

[0159] Energy compensation unit, used to perform energy compensation on each perforation signal;

[0160] The perforation signal analysis unit is used to analyze the differences in recognition rate, positioning accuracy, moment magnitude, and signal-to-noise ratio of each segment of the perforation signal after energy compensation;

[0161] The abnormal operation section identification unit is used to select the suspected abnormal perforation signal from each section of the perforation signal according to the analysis result, and identify the well section corresponding to the suspected abnormal perforation signal as the abnormal operation section;

[0162] The microseismic event point spatial position analysis unit is used to count the number, moment magnitude, and sweep direction of microseismic events in each segment, and analyze the spatial position of microseismic event points in each segment;

[0163] The microseismic event spatiotemporal distribution analysis unit is used to analyze the spatiotemporal distribution morphological characteristics of microseismic events in each section during the fracturing operation;

[0164] A suspected cementing quality abnormal section identification unit is used to identify the suspected cementing quality abnormal section from each section according to the temporal and spatial distribution morphological characteristics obtained by analysis;

[0165] The cementing quality abnormal section confirmation unit is used to eliminate the well sections with abnormal microseismic distribution caused by natural fracture zones. Among the remaining well sections, if a well section is identified as a construction abnormal section and also identified as a suspected cementing quality abnormal section, then the well section is confirmed as a cementing quality abnormal section.

[0166] The whole-well section cementing quality evaluation unit is used to realize the cementing quality evaluation of the whole-well section according to the confirmation result.

[0167] In some embodiments, in the moment magnitude calculation unit, the moment magnitude M is calculated according to the following formula: w :

[0168]

[0169]

[0170] Among them, ρ 0 is the density, v 0 is the wave velocity, R is the distance from the source to the seismic pickup, Ω 0 is the lowest frequency level of displacement, F c It is a radiation field type.

[0171] In some implementations, the abnormal construction section identification unit is specifically used to:

[0172] According to the analysis results, perforation signals with low signal-to-noise ratio, low recognition rate and abnormal wave field characteristics are identified as suspected abnormal perforation signals, and the well section corresponding to the suspected abnormal perforation signal is identified as the abnormal operation section.

[0173] In some embodiments, the suspected cementing quality abnormal section identification unit includes:

[0174] The first identification subunit is used to identify the section as not suspected of cementing quality abnormality if the construction displacement is stable and the fracturing fluid is continuously injected, the microseismic event points appear evenly and extend vertically along both sides of the wellbore in this section.

[0175] In some embodiments, the suspected cementing quality abnormal section identification unit includes:

[0176] The second identification subunit is used to determine that if the construction displacement is stable and the fracturing fluid is continuously injected, the microseismic event point is asymmetric with the wellbore, and most of the microseismic event points between different fracturing sections overlap and are distributed linearly, the section is judged to be affected by the natural fracture zone, and the section is identified as not a suspected cementing quality abnormal section.

[0177] In some embodiments, the suspected cementing quality abnormal section identification unit includes:

[0178] The third identification subunit is used to identify the section as a suspected cementing quality abnormal section if the overlapping microseismic event points between different fracturing sections exceed a preset ratio and are all distributed near the overlapping points near the wellbore as the fracturing fluid is continuously injected.

[0179] In some embodiments, the suspected cementing quality abnormal section identification unit includes:

[0180] The fourth identification subunit is used to identify the section as a suspected abnormal cementing quality section if microseismic events occur across sections as the fracturing fluid is continuously injected and extend vertically along both sides of the wellbore in this section in a linear distribution as the fracturing progresses.

[0181] In some embodiments, the suspected cementing quality abnormal section identification unit includes:

[0182] The fifth identification subunit is used to identify the section as a suspected abnormal cementing quality section if the microseismic events suddenly decrease with the continuous injection of fracturing fluid, the construction displacement is stable, there are no fracture development zone characteristics around the section, and the geological characteristics do not change much.

[0183] In some embodiments, the suspected cementing quality abnormal section identification unit includes:

[0184] The fifth identification subunit is used to comprehensively analyze the spatiotemporal distribution morphological characteristics of microseismic event points and the moment magnitude of microseismic events. If a large moment magnitude occurs and the occurrence rate is concentrated, accompanied by a decrease in construction pressure, it is judged that the section is a hydraulic fracturing artificial fracture that has entered the natural fracture zone, and the section is identified as not a suspected cementing quality abnormality section.

[0185] This embodiment is based on the characteristics of microseismic events caused by the sliding of rocks along weak surfaces caused by the entry of liquid into the formation during fracturing construction, and effectively evaluates the cementing quality of each section of the horizontal well. This technology is based on the dynamic parameters such as fracture energy, extension direction, and extension characteristics of microseismic monitoring during fracturing construction, combined with perforation signals and seismic attribute characteristics, to comprehensively evaluate the differences in cementing quality of each section; multi-parameter fusion technology effectively improves the accuracy of cementing quality evaluation, and at the same time provides an effective data basis for real-time adjustment of fracturing construction with poor cementing quality, optimizes and adjusts the fracturing process, and improves the effect of reservoir transformation.

[0186] For other detailed descriptions and advantages of this embodiment, reference may be made to the corresponding descriptions in the aforementioned embodiments, which will not be repeated here.

[0187] Example 3

[0188] According to another aspect of the present invention, an electronic device is provided. The electronic device comprises:

[0189] Memory, which stores executable instructions:

[0190] A processor runs the executable instructions in the memory to implement the cementing quality assessment method based on microseismic monitoring technology according to the present invention.

[0191] Specifically, the memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, a random access memory (RAM) and / or a cache memory (cache), etc. The non-volatile memory may include, for example, a read-only memory (ROM), a hard disk, a flash memory, etc.

[0192] The processor may be a central processing unit (CPU) or other forms of processing units with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions. In one embodiment of the present invention, the processor is used to run the computer-readable instructions stored in the memory.

[0193] For detailed description of this embodiment, reference may be made to the corresponding descriptions in the aforementioned embodiments, which will not be repeated here.

[0194] Example 4

[0195] According to another aspect of the present invention, a computer-readable storage medium is provided, which stores a computer program. When the computer program is executed by a processor, the cementing quality assessment method based on microseismic monitoring technology according to the present invention is implemented.

[0196] The computer-readable storage medium according to the embodiment of the present invention stores non-transitory computer-readable instructions, and when the non-transitory computer-readable instructions are executed by a processor, all or part of the steps of the above-mentioned methods of the embodiments of the present invention are executed.

[0197] The above-mentioned computer-readable storage media include, but are not limited to: optical storage media (e.g., CD-ROM and DVD), magneto-optical storage media (e.g., MO), magnetic storage media (e.g., magnetic tape or mobile hard disk), media with built-in rewritable non-volatile memory (e.g., memory card) and media with built-in ROM (e.g., ROM box).

[0198] Those skilled in the art should be able to understand that in order to solve the technical problem of how to obtain a good user experience, the present embodiment may also include well-known structures such as a communication bus and an interface, and these well-known structures should also be included in the protection scope of the present invention.

[0199] For detailed description of this embodiment, reference may be made to the corresponding descriptions in the aforementioned embodiments, which will not be repeated here.

[0200] Example 5

[0201] The following is an exemplary verification and explanation of the implementation effect of the cementing quality assessment scheme based on microseismic monitoring technology according to the present invention using a specific exemplary embodiment.

[0202] A horizontal well fracturing well was selected as an example. Conventional density cement slurry was used for cementing in the whole well section. The cementing logging project was acoustic amplitude-variable density. The measured well section was 14.00~5009.00m. According to statistics, the fracture sections corresponding to the poor cementing quality in the horizontal section were the 6th, 7th, 10th, 11th, 14th, 15th, 16th, 17th, 21st, 22nd, 23rd and 24th sections. Based on the microseismic monitoring results, the perforation signals of this well were weak in energy, low in recognition, and unclear in arrival. Only 5 sections of perforation signals were identified. The microseismic monitoring perforation signals of wells in the same type and similar areas of this work area were quite different. During the fracturing period, there were 5 sections in the whole well section (sections 10, 11, 12, 18 and 23). There were abnormal event points in adjacent sections during the fracturing period. Combined with the microseismic wave characteristics and construction conditions, there was a possibility of affecting other sections. During the fracturing of section 10, strong fracture energy appeared on the east wing of section 9. Figure 2 The horizontal schematic diagram of the microseismic events of the 9th and 10th sections according to the exemplary embodiment is shown; during the fracturing of the 11th section, individual weak energy appeared on the west wing of the 10th section, and during the fracturing of the 12th section, an abnormal event point appeared near the west wing of the 11th section. Figure 3 Schematic diagrams of the horizontal direction of microseismic events in the 10th, 11th and 12th segments according to this exemplary embodiment are shown. Figure 6 The schematic diagram of the microseismic monitoring profile of the third cluster perforation of the 10th segment according to the exemplary embodiment is shown; during the 18th segment fracturing, multiple strong fracture energies appeared on the west wing of the 17th segment, Figure 4The horizontal direction of the microseismic events of the 17th and 18th sections according to this exemplary embodiment is shown; during the fracturing of the 23rd section, multiple abnormal events occurred on the west wing of the 22nd section, Figure 5 The horizontal schematic diagram of the 22nd and 23rd microseismic events according to this exemplary embodiment is shown. Analysis shows that the poor cementing quality of this well is significantly correlated with microseismic events. The cementing quality section is effectively evaluated based on microseismic monitoring. At the same time, during on-site construction, the engineering process of poor cementing quality is optimized based on the microseismic monitoring results, and the temporary plugging process is adopted to improve the reservoir transformation effect of poor cementing quality.

[0203] In summary, the embodiments of the present invention are based on the characteristics of microseismic events caused by the sliding of rocks along weak surfaces due to the entry of liquid into the formation during fracturing construction, and effectively evaluate the cementing quality of each section of the horizontal well. This technology is based on dynamic parameters such as fracture energy, extension direction, and extension characteristics monitored by microseismic monitoring during fracturing construction, combined with perforation signals and seismic attribute characteristics, to comprehensively evaluate the differences in cementing quality of each section; multi-parameter fusion technology effectively improves the accuracy of cementing quality evaluation, and at the same time provides an effective data basis for real-time adjustment of fracturing construction with poor cementing quality, optimizes and adjusts the fracturing process, and improves the effect of reservoir transformation. The advantages of this technical solution are described in detail below.

[0204] 1. Improved the accuracy of cementing quality evaluation.

[0205] The present invention takes into account dynamic information such as rupture energy and extension direction through analysis and evaluation of microseismic multi-parameters, and the evaluation result is more accurate and comprehensive.

[0206] 2. It provides an optimization basis for on-site construction.

[0207] The present invention can evaluate cementing quality in real time, discover problematic well sections, and provide an effective reference for optimizing and adjusting the fracturing process on site.

[0208] 3. The scope of evaluation has been expanded.

[0209] The present invention does not carry out cementing quality detection in the well section, and the method can also be used to implement evaluation during the fracturing process, thereby expanding the scope of application.

[0210] 4. Reduced evaluation costs.

[0211] Compared with the traditional optical fiber monitoring method, the present invention uses the microseismic information during the fracturing process for evaluation, avoiding the high cost of laying additional optical fibers.

[0212] 5. Improved the reservoir transformation effect of oil and gas fields.

[0213] The evaluation results can provide a basis for subsequent improvement of cementing quality, reduce fracturing losses, better transform oil and gas reservoirs, and increase production capacity.

[0214] 6. Optimized the benefits of oil and gas development.

[0215] Accurate evaluation and improvement of cementing quality can extend the life of oil and gas wells and significantly improve the economic benefits of development.

[0216] It can be understood that the above embodiments mentioned in the present disclosure can be combined with each other to form a combined embodiment without violating the principle logic. Due to space limitations, the present disclosure will not repeat them. It can be understood by those skilled in the art that in the above methods of the specific implementation, the specific execution order of each step should be determined according to its function and possible internal logic.

[0217] Note that, unless otherwise directly stated, all features disclosed in this specification (including any attached claims, abstracts and drawings) may be replaced by alternative features for achieving the same, equivalent or similar purposes. Therefore, unless otherwise explicitly stated, each feature disclosed is only an example of a group of equivalent or similar features. Where used, further, preferably, further and more preferably are simple beginnings for elaborating another embodiment based on the aforementioned embodiment, and the content of the further, preferably, further or more preferably followed by the combination with the aforementioned embodiment constitutes a complete construction of another embodiment. Several further, preferably, further or more preferably settings following the same embodiment can be arbitrarily combined to form another embodiment.

[0218] It should be understood by those skilled in the art that the embodiments of the present invention described above and shown in the accompanying drawings are only examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and explained in the embodiments, and the embodiments of the present invention may be deformed or modified in any way without departing from the principles.

[0219] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A cementing quality assessment method based on microseismic monitoring technology, It is characterized in that The method comprises: Step 1: Analyze the characteristics of microseismic monitoring data of each section of perforation in the horizontal well, analyze the wave clarity, identifiability, and signal frequency of each section of perforation signal, and obtain analysis data; Step 2: Based on the analysis data, calculate the moment magnitude M of each microseismic event corresponding to each cluster perforation. w ; Step 3, performing energy compensation on each perforation signal; Step 4, after energy compensation, analyze the differences in recognition rate, positioning accuracy, moment magnitude, and signal-to-noise ratio of each segment of perforation signal; Step 5: According to the analysis results, a suspected abnormal perforation signal is selected from each section of the perforation signal, and the well section corresponding to the suspected abnormal perforation signal is identified as the abnormal operation section; Step 6, counting the number, moment magnitude, and sweep direction of microseismic events in each segment, and analyzing the spatial position of microseismic event points in each segment; Step 7, analyzing the temporal and spatial distribution morphological characteristics of microseismic events in each section during the fracturing operation; Step 8, identifying suspected cementing quality abnormal sections from each section according to the temporal and spatial distribution morphological characteristics obtained by analysis; Step 9, eliminating the well sections with abnormal microseismic distribution caused by natural fracture zones. Among the remaining well sections, if a well section is identified as a construction abnormality section and also identified as a suspected cementing quality abnormality section, then the well section is confirmed to be a cementing quality abnormality section; Step 10: Based on the confirmation results, the cementing quality of the entire well section is evaluated.

2. The method according to claim 1, It is characterized in that In step 2, the moment magnitude M is calculated according to the following formula w : Among them, ρ 0 is the density, v 0 is the wave velocity, R is the distance from the source to the seismic pickup, Ω 0 is the lowest frequency level of displacement, F c It is a radiation field type.

3. The method according to claim 1, It is characterized in that Step 5 specifically includes: According to the analysis results, perforation signals with low signal-to-noise ratio, low recognition rate and abnormal wave field characteristics are identified as suspected abnormal perforation signals, and the well section corresponding to the suspected abnormal perforation signal is identified as the abnormal construction section.

4. The method according to claim 1, It is characterized in that The step 8 specifically includes: If the construction displacement is stable, with the continuous injection of fracturing fluid, microseismic event points appear evenly and extend vertically along both sides of the wellbore in this section, it can be identified that this section is not a suspected cementing quality abnormal section.

5. The method according to claim 1, It is characterized in that The step 8 specifically includes: If the construction displacement is stable and the fracturing fluid is continuously injected, the microseismic event point is asymmetric with the wellbore, and most of the microseismic event points between different fracturing sections overlap and are distributed linearly, it is judged that this section is affected by the natural fracture zone and is identified as not a suspected section with abnormal cementing quality.

6. The method according to claim 1, It is characterized in that The step 8 specifically includes: If, with the continuous injection of fracturing fluid, the overlapping microseismic event points between different fracturing sections exceed the preset ratio and are all distributed near the wellbore of the overlapping points, the section is identified as a suspected section with abnormal cementing quality.

7. The method according to claim 1, It is characterized in that The step 8 specifically includes: If the microseismic events occur across sections as the fracturing fluid is continuously injected, and extend vertically along both sides of the wellbore in this section as the fracturing progresses, showing a linear distribution, the section can be identified as a suspected section with abnormal cementing quality.

8. The method according to claim 1, It is characterized in that The step 8 specifically includes: If the microseismic events suddenly decrease with the continuous injection of fracturing fluid, the construction displacement is stable, there is no fracture development zone around this section, and the geological characteristics do not change much, this section is identified as a suspected section with abnormal cementing quality.

9. The method according to claim 1, It is characterized in that The step 8 specifically includes: Comprehensively analyze the spatiotemporal distribution morphological characteristics of microseismic event points and the moment magnitude of microseismic events. If a large moment magnitude occurs and the occurrence rate is concentrated, accompanied by a decrease in construction pressure, it is judged that the section is a hydraulic fracturing artificial fracture that has entered the natural fracture zone, and this section is identified as not a suspected cementing quality abnormality section.

10. A cementing quality assessment device based on microseismic monitoring technology, It is characterized in that The device comprises: The raw data analysis unit is used to analyze the characteristics of microseismic monitoring data of each section of perforation in the horizontal well, analyze the wave clarity, identifiability, and signal frequency of each section of perforation signal, and obtain analysis data; The moment magnitude calculation unit is used to calculate the moment magnitude M of each microseismic event corresponding to each cluster perforation according to the analysis data. w ; Energy compensation unit, used to perform energy compensation on each perforation signal; The perforation signal analysis unit is used to analyze the differences in recognition rate, positioning accuracy, moment magnitude, and signal-to-noise ratio of each segment of the perforation signal after energy compensation; The abnormal operation section identification unit is used to select the suspected abnormal perforation signal from each section of the perforation signal according to the analysis result, and identify the well section corresponding to the suspected abnormal perforation signal as the abnormal operation section; The microseismic event point spatial position analysis unit is used to count the number, moment magnitude, and sweep direction of microseismic events in each segment, and analyze the spatial position of microseismic event points in each segment; The microseismic event spatiotemporal distribution analysis unit is used to analyze the spatiotemporal distribution morphological characteristics of microseismic events in each section during the fracturing operation; A suspected cementing quality abnormal section identification unit is used to identify the suspected cementing quality abnormal section from each section according to the temporal and spatial distribution morphological characteristics obtained by analysis; The cementing quality abnormal section confirmation unit is used to eliminate the well sections with abnormal microseismic distribution caused by natural fracture zones. Among the remaining well sections, if a well section is identified as a construction abnormal section and also identified as a suspected cementing quality abnormal section, then the well section is confirmed as a cementing quality abnormal section. The whole-well section cementing quality evaluation unit is used to realize the cementing quality evaluation of the whole-well section according to the confirmation result.

11. An electronic device, It is characterized in that The electronic device comprises: A memory storing executable instructions; A processor, wherein the processor runs the executable instructions in the memory to implement the method according to any one of claims 1 to 9.

12. A computer-readable storage medium storing a computer program, wherein the computer program implements the method according to any one of claims 1 to 9 when executed by a processor.

Images