193 results about "Microearthquake" patented technology

An energy-based method for automatically locating the earthquake focus of a microearthquake belongs to the field of microearthquake detection, and relates to an earthquake focus locating method used in a microearthquake monitoring system, in particular to an automatic microearthquake locating method and a method for improving the locating accuracy. The invention adopts an earthquake wave dynamic method which is an earthquake locating algorithm based on earthquake wave energy attenuation equation, complicated calculation of energy of the earthquake waves is not required, parameters such as themaximum shake amplitude or quadratic sum of the shake amplitude and the like are adopted to represent energy, and the arrival time of the earthquake waves does not need to be picked up at all, so that problems caused during automatic locating of the earthquake focus of the microearthquake are solved; and as energy difference is taken as the optimized variable, while energy attenuation is in direct correlation with range, the defect that the travel-time difference serving as the optimized variable is only related to the travel-time difference (range difference) but not in direct correlation with the size of the range per se, the external-field locating accuracy, particularly the accuracy in the vertical direction, is improved, and the stability of the locating result is also improved.

The invention discloses an EnKF microearthquake event position inversion method based on a perforation restraint. The EnKF microearthquake event position inversion method comprises the following steps of: (1) building a speed field; (2) selecting a kth event point; (3) acquiring first arrival traveling time of the event point received by a jth detector through a solving eikonal equation; (4) fitting the first arrival traveling time obtained in the step (3) with first arrival traveling time which is actually received by the jth detector; and (5) checking whether the traveling time of the event point received by each detector is completely fitted, if the traveling time of the event point received by each detector is not completely fitted, returning to the step (3), and adding 1 to a variable j to fit the (j+1)th detector, otherwise, finishing event positioning.

The invention discloses a detection evaluation method for a microearthquake multi-dimensional information integration area of an impact danger zone. The method comprises the following steps: (1) space coordinates rotation and classifying screening of mine earthquake data are performed; (2) a microearthquake multi-dimensional information detection evaluation index system is established; (3) a space statistic slippage model is created; (4) a microearthquake multi-dimensional information integration detection evaluation index value W is calculated according to the following formula; and (5) a danger class and control countermeasures corresponding to the danger class are determined according to the microearthquake multi-dimensional information integration detection evaluation index value W; and the larger the microearthquake multi-dimensional information integration detection evaluation index value W is, the higher the danger class is. The method integrally considers three elements of the microearthquake space time magnitude, quantitatively describes the impact danger degree, can reflect an impact danger area and the danger class in the current time period in real time, can guide a site to take corresponding control countermeasures, and is extremely high in prediction effect, high in operability and high in arithmetic speed; and physical significance of the established detection evaluation index system and an integration index is definite.

The invention discloses a method for microearthquake positioning and anisotropic speed structure tomography. The method comprises the following specific steps that 1, an initial model is read, and parameters are inversed; 2, theoretical travel time and a ray path of a microearthquake event are calculated in an anisotropic medium; 3, first-order partial derivatives about to-be-inversed parameters when the anisotropic speed structure and microearthquake event parameters of an underground medium are inversed at the same time are calculated; 4, a chromatography equation set for inversing the anisotropic speed structure and the microearthquake event parameters of the underground medium is established; 5, the chromatography equation set is solved through a sub-space method, and updating values of microearthquake source parameters and the anisotropic speed structure of the medium are obtained; 6, an anisotropic speed structure model and the earthquake source parameters are updated and restrained; 7, iteration judgement is stopped. According to the method, for a horizontal layered anisotropic TI medium, by using ground and in-well observation travel time data, the earthquake source parameters and the anisotropic speed structure of the medium can be inversed at the same time.

The invention provides a rock slope deformation pre-warning method based on microearthquake apparent stress. The method includes the steps of (1) installing and arranging an ESG microearthquake monitoring system in a monitoring area; (2) conducting blasting excavation construction on the monitoring area, wherein since blasting excavation construction can cause microearthquake events in the monitoring area, the monitoring area is monitored through the ESG microearthquake monitoring system; (3) during monitoring, when the occurrence frequency of a high apparent stress microearthquake event within 4 days in partial regions in the monitoring area is larger than or equal to 2, drawing a curve graph of average microearthquake apparent stress changing along with the time and a curve graph of accumulated microearthquake apparent volume changing along with the time separately; if an average microearthquake apparent stress curve in the curve graph sharp increases from a gentle state to a peak value and then sharp decreases and meanwhile an accumulated apparent volume curve changes from a gentle state to a constantly increasing state, giving a rock slope deformation pre-warning to the partialregions. The method can effectively improve the accuracy of the rock slope deformation pre-warning.

The invention relates to a method for obtaining a microearthquake wave velocity based on a space geometry relationship. The method comprises the following steps: constructing an inequation of microearthquake equivalent wave velocity V according to the space geometry relationship of an earthquake focus point and a base station, constructing a regularly changing time difference fitness function shaped like a quadratic function with an upward opening, proposing a monotonous unidirectional searching algorithm, and resolving an optimum wave velocity. The method perfectly solves the problem that a velocity model in microearthquake positioning is inaccurate or non-unique, and does not need any prior engineering experience; the microearthquake wave velocity can be quickly and precisely solved according to the observation data of sensors for microearthquake arrival time, so that the positional accuracy of a microearthquake positioning algorithm in a later period is guaranteed, the rate of convergence and the stability of the algorithm are improved, and the method has an extremely high practical engineering application value.

The invention discloses a method for calculating the propagation speed of earthquake waves in a mine region by utilizing a microearthquake point as an earthquake source, comprising the following steps: determining the coordinate estimated value of the microearthquake point according to the earthquake wave time generated by the microearthquake point measured by multiple preset sensors; determiningall possible propagation paths of the earthquake waves generated by the microearthquake point to the preset sensors according to the coordinate estimated value of the microearthquake point and the speed layer where the preset sensors are; selecting the possible propagation path with the difference between the earthquake wave propagation time and the earthquake wave time measured by the preset sensors corresponding to a preset range from all the possible propagation paths as a fixed propagation path; and calculating the propagation speed of the earthquake waves according to the determined fixed propagation path and the initial value of a three-dimensional continuous speed diamond on the fixed propagation path.

The embodiment of the invention provides a microearthquake event detecting and positioning method and apparatus. The method includes the following steps: obtaining P-wave correction time differences and S-wave correction time differences between each grid in a grid structure of a template event and different observation stations, and also obtaining P-wave cross correlation coefficients and S-wave cross correlation coefficients of the template event; determining first superposed cross correlation coefficients of each grid at different times on the basis of the P-wave cross correlation coefficients between P-waves of the template event and each observation station at different times, the S-wave cross correlation coefficients between S-waves of the template event and each observation station at different times, and the P-wave correction time differences and the S-wave correction time differences between each grid and the different observation stations; determining position and time of a microearthquake event corresponding to the template event according to the first superposed cross correlation coefficients of each grid at different times and a first preset threshold value. In this way, a microearthquake event low in signal to noise ratio can be detected and positioned accurately.

The invention provides a micro seismic signal time-frequency domain first arrival detection method. The method includes the following steps that: when the ICEEMDAN (improved complete ensemble empirical mode decomposition with adaptive noise) is adopted to perform data processing, microseismic signals are used as initial data, a specific white noise is added at each stage of decomposition, and a unique residual is calculated, so that each IMF (intrinsic mode function) can be obtained; the ICEEMDAN can adaptively decompose a complex signal into a series of IMF components which satisfy high frequency-to-low frequency series distribution; with the IMF components adopted as input, noise dominant modalities are directly removed, and other modalities are subjected to DFA (detrended fluctuation analysis) de-noising, and residual noises are removed through an interval hard threshold method; denoised results of different scales are fused and reconstructed, so that denoised seismic records, namely, effective signals can be obtained; and the first arrival information of the effective signals is obtained through high-precision time-frequency analysis detection. Compared with an empirical mode decomposition result, the method can significantly reduce modal aliasing phenomena, realize accurate reconstruction of original signals and has better convergence.

The invention discloses an in-well seismic data acquisition device and acquisition method based on an MEMS optical fiber detector, and the device comprises a ground artificial seismic source and a plurality of in-well three-component optical fiber seismic signal receiving and acquisition short circuits which are connected with a ground composite modulation and demodulation instrument through armored photoelectric composite cables. The armored photoelectric composite cable controls the depth position of the three-component optical fiber seismic signal receiving and collecting pup joint in the well and synchronously collects DASVSP data; a three-component optical fiber seismic signal sensor module and a three-component optical fiber attitude sensor are installed in each in-well three-component optical fiber seismic signal receiving and acquisition short circuit. The device is high in sensitivity, the acquisition device is very simple, the acquisition device descends into all high-temperature wells to acquire three-component seismic data or micro-seismic data in the high-quality wells, DAS-VSP data of the whole well section above a detector are synchronously acquired, and powerful technical support is provided for application of the oil reservoir geophysical technology.

The invention discloses an anti-seismic earth-retaining wall suitable for a microearthquake region as well as a construction method thereof. The anti-seismic earth-retaining wall suitable for the microearthquake region comprises an upper structure, a lower structure and an anti-seismic buffer layer; the upper structure is arranged on the lower structure; a plurality of bulges are arranged at the bottom; a plurality of water discharging holes and a fixed plate are arranged in the wall; a water-collecting tank is arranged at the position of the water discharging hole on the back side of the wall; the lower structure is arranged on a gravel cushion layer; a plurality of grooves are formed at the bottom of the lower structure; a damping device is arranged between the bulges and the grooves; steel plates are arranged on the upper part and the lower part of the damping device; the anti-seismic buffer layer is arranged in a backfill layer behind the wall; one end, near the wall, of the anti-seismic buffer layer and the fixed plate are connected together; and water-permeable geotechnical cloth is arranged on the upper surface and the lower surface of the anti-seismic buffer layer. After microearthquake arrives at the wall, the damping device on the lower part of the wall and the anti-seismic buffer layer behind the wall can absorb earthquake ability, so that the damping effect is achieved and harm on the earth-retaining structure by the earthquake is reduced.

The invention relates to a micro-seismic phase identification first picking method and device, and a storage medium. In the method, an energy-weighted similarity coefficient is calculated along a fitting curve for signal identification, a micro-seismic signal can be quickly and effectively identified; and based on a known seismic phase first arrival trend, a residual time difference correction value of a target seismic phase is calculated, a constraint time window is set, a situation that large errors occur in low-signal-to-noise-ratio channel record first picking can be effectively avoided, and first picking efficiency and accuracy are improved. The method, the device and the medium have important significance in improving fracturing construction efficiency and increasing a success rate of oil and gas reservoir transformation.

The invention discloses a microseism ground monitoring device and a seismic source positioning method. The microseism ground monitoring device comprises a data acquisition and processing module, a signal transmission module and a power supply module. The data acquisition and processing module comprises a geophone used for receiving a microseism analog signal; the geophone is connected with a signal conditioning module, which is connected with an A/D conversion module; the A/D conversion module is connected with a processor module, which is respectively connected with a data storage module anda global navigation satellite module; the processor module is connected with the signal transmission module; and the power supply module is connected with the data acquisition and processing module and is used for supplying power to the data acquisition and processing module. According to the invention, a superimposed energy scanning imaging technology which does not need to extract the first arrival of a signal event is adopted to carry out ground seismic source positioning, and the seismic source position can be effectively determined on the premise of not high requirement on signal source quality; microseism real-time positioning and monitoring can be supported through the server; and meanwhile, a mobile 4G signal is adopted, and the advantage of low signal transmission cost is achieved.

The invention discloses a ground microseism positioning method and system combining seismic source mechanism inversion, and the method comprises the steps: determining a theoretical travel time tableby employing a P-wave and S-wave speed model according to an observation system and a target region; obtaining the amplitude of the microseism data channel according to the theoretical travel time table, and correcting the polarity of the corresponding amplitude according to the theoretical prediction polarity before superposition; and determining the position of the seismic source according to the amplitude superposition energy after polarity correction. According to the microseism positioning method combining seismic source mechanism rapid inversion, waveform information of P waves and S waves in data is utilized, seismic source mechanism solution inversion calculation is rapid and stable, the radiation pattern problem caused by a complex seismic source mechanism can be effectively solved, and the scanning superposition positioning precision is improved; and moreover, the method can automatically detect and position the microseism event without manually picking up the first arrival of the P wave and the S wave, thereby further avoiding the influence of a picking error on the positioning precision.

The invention provides a method and system for solving an oil reservoir reconstruction microseism monitoring fracture seismic source mechanism. The method comprises the following steps: step 1, obtaining observation microseism waveform data of a time domain; step 2, establishing a three-dimensional speed model of an oil reservoir transformation area; step 3, acquiring an energy ratio of longitudinal waves to transverse waves of microseism signals; step 4, according to a Bayesian formula, calculating a probability density function between a longitudinal wave and transverse wave energy ratio anda point seismic source property through a training sample; and step 5, according to the calculated probability density function, judging the seismic source property of a microseism event by utilizingthe longitudinal wave and transverse wave energy ratio, and solving the seismic source mechanism of the microseism event. According to the method and the system for solving the oil reservoir reconstruction microseism monitoring fracture source mechanism, whether an artificial fracture is a tensile fracture or a shear fracture can be determined through the method for solving the oil reservoir reconstruction microseism monitoring fracture source mechanism, so that the accurate characteristics of the artificial fracture are effectively described.

The invention discloses a quasi-holographic dense monitoring system for forecast and fast reporting of earthquakes. The quasi-holographic dense monitoring system comprises ultra-microearthquake observation stations arranged at an interval of 10+/-5 km, strong earthquake observation stations arranged at an interval of 30+/-10 km, earthquake mass prediction and prevention centers set in prefecture-level cities, and provincial earthquake mass prediction and prevention centers that are built in all provinces, wherein the earthquake mass prediction and prevention centers set in prefecture-level cities are used for receiving and displaying in real time data information transmitted by the ultra-microearthquake observation stations and the strong earthquake observation stations, and the provincial earthquake mass prediction and prevention centers are used for receiving in real time the data information of earthquakes with a magnitude greater than 6 in prefecture-level cities. Thus an intensive quasi-holographic monitoring system for forecast and fast reporting of earthquakes is formed and can be used for monitoring local earthquakes with a magnitude ranging from -1 to +9. The quasi-holographic dense monitoring system is advantageous in that monitoring spots are densely arranged, earthquake information can be quickly obtained through networks, the position of the epicentral area of a local earthquake with a magnitude greater than 4 can be reported quickly within one minute with epicenter error being +/-5 km, and the efficiency of disaster rescue and relief work can be improved.

The invention provides an earthquake source mechanism inversion method and device based on rock characteristics, and relates to the technical field of micro-earthquake monitoring. The method comprises the steps: firstly collecting a micro-earthquake signal of a target monitoring region; predicting target rock features corresponding to the micro-earthquake signal based on the target relation model; and finally, based on the target rock characteristics, inverting an earthquake source mechanism of a fracture event in the target monitoring region. According to the invention, the authenticity of the data used for inverting the earthquake source mechanism can be ensured by collecting the micro-earthquake signal of the target monitoring region, and the rock characteristics of the fracture event in the target monitoring region can be obtained by predicting the target rock characteristics corresponding to the micro-earthquake signal according to the target relation model. The rock characteristics can avoid multiplicity of solutions of the earthquake source mechanism, and then a real, effective and unique earthquake source mechanism is obtained.

The invention discloses a rock burst premonition identification method based on microearthquake frequency spectrum evolution. The method specifically comprises the steps that (1) a sensor in a microearthquake monitoring system detects rock burst and converts the rock burst into a microearthquake signal which is transmitted to a data processing module in the microearthquake monitoring system; (2) the microearthquake signal is filtered through the data processing module of the microearthquake monitoring system so that the interference of noise signals can be eliminated; (3) data extraction is conducted on the filtered signal through a spectral analysis module of the microearthquake monitoring system; (4) the extracted data are used for calculating the ratio of energy on the same frequency band (with intervals of 1Hz) to total energy, namely basic frequency; (5) the basic frequency of the processed microearthquake signal is displayed through an oscilloscope. By means of spectral analysis of the microearthquake signal and display achieved through the oscilloscope, real-time display for warning can be realized, and accuracy is high.

The invention relates to an automatic microearthquake focus positioning method. The automatic microearthquake focus positioning method comprises the step of establishing k quaternary linear equation sets according to acquired information of n effective channels, wherein n represents the number of the effective channels and is larger than or equal to four; the step of solving all of the quaternary linear equation sets to obtain l sets of results, wherein l is smaller than or equal to k; the step of respectively substituting the l sets of results into a focus positioning target equation to obtain n deviation values corresponding to the effective channels; the step of judging whether the n deviation values are in the error range or not, where if yes, the deviation target function value F(x0, y0, z0) in the focus positioning target equation is output, and if not, the information of the effective channels corresponding to the deviation values not in the error range in the deviation values is changed; the step of establishing the k quaternary linear equation sets according to acquired information of the n effective channels. The automatic microearthquake focus positioning method is achieved through a computer, and time and labor are saved.

The invention provides a three-component P-wave initial motion seismic focus mechanism inversion method and device. The method may include the following steps: 1) three component P-wave initial motionsymbols are extracted from microseismic ground shallow well monitoring data; 2) symbol correction is performed on X and Y component P-wave initial motion symbols; 3) a seismic focus model is selected; according to the microseismic ground shallow well monitoring data, values of seismic focus model parameters are solved to determine a seismic focal mechanism solution; 4) lattice point dispersion isperformed in a seismic focal mechanism space; 5) lattice points in the seismic focal mechanism space are searched. In a searching process, a Z component P-wave initial motion symbol corresponding tothe seismic focal mechanism is calculated; 6) degrees of matching is calculated; and 7) the seismic focal mechanism corresponding to a component with a maximum degree of matching is selected as an inversion result. The inversion method and device disclosed in the present invention are used for constraining inversion of the seismic mechanism via three components at the same time, accuracy of inversion can be increased, and multiplicity of solutions of the inversion result can be reduced.

The invention discloses a microearthquake or acoustic emission abnormal arrival time determining method. The method comprises the steps of conducting primary processing on n obtained arrival time data according to conditions in a microearthquake or acoustic emission test, so that m sets of arrival time data are obtained; obtaining m sets of microearthquake sources or acoustic emission coordinates by means of the m sets of arrival time data; fitting m sets of microearthquake or acoustic emission positioning results with a Logistic probability distribution function, and obtaining Logistic probability distribution functions Fx, Fy and Fz about x, y and z respectively; obtaining the Logistic probability distribution functions Fx, Fy and Fz when Fx, Fy and Fz are smaller than 0.005, finding positioning results meeting the solutions from the m sets of positioning results, and calling the positioning results as abnormal positioning results, wherein arrival time data corresponding to the abnormal positioning results contain abnormal arrival time data. The method has the advantages of being high in precision and easy to realize.