396 results about "Seismic inversion" patented technology

A method for estimating and/or reducing uncertainty in reservoir models of potential petroleum reservoirs comprises receiving the results of a stochastic seismic inversion, and transforming the inversion data into a form suitable for reservoir modelling and flow simulations, while honoring inter-property and inter-layer correlations in the inversion data as well as measured well data and other geological constraints.

The invention provides a gas pool prediction method and system of a carbonate reservoir based on pore structure characteristics. The method comprises the following steps: collecting a rock sample of a target reservoir section of the carbonate reservoir; authenticating geological thin sheets of the rock sample so as to obtain rock basic parameters comprising the rock constituents, the pore shape, the surface porosity and the sedimentary phase belt; carrying out pore permeation measurement on the rock sample so as to obtain pore permeation basic parameters comprising the porosity, the permeation rate and the density; constructing a rock bare-bone model according to the rock basic parameters, the pore permeation basic parameters and a differential equivalent medium model; carrying out fluid replacement on the rock bare-bone model so as to generate a rock physical plate; acquiring prestack seismic inversion data of the carbonate reservoir; intersecting the prestack seismic inversion data and the rock physical plate, thereby obtaining the prediction results of the porosity and the gas saturation of the carbonate reservoir. The accurate quantitative gas pool prediction is realized.

A method is disclosed for determining improved estimates of properties of a model, on the basis of estimated prior constraints, by running a mathematical inversion several times using the output posterior estimate of the previous inversion, or any of the previous inversions to provide an input for the next inversion. This iterative inversion may be repeated until the prior and posterior estimates converge to within a given threshold. The method may be applied to seismic data, using a seismic inversion, in order to improve the prediction of the viability of potential petroleum reservoirs by determining improved estimates of volumetric properties of a subsurface region.

A seismic rock physics inversion method based on a large area tight reservoir includes steps: building a multi-scale rock physics model; analyzing fluid sensitivities of rock physics parameters in two scales of acoustic logging and ultrasonic wave, and sifting the rock physics parameters that are most sensitive to a porosity and a gas saturation in a plurality of observation scales; building a single-well rock physics template, preferably a standard template; considering lateral variations and heterogeneity of reservoir geological features, fine-tuning input parameters of the rock physics template according to gas testing situations of all wells in a large work area, optimizing the whole work area and building a three-dimensional work area rock physics template data volume, and combining the data volume with pre-stack seismic inversion to calculate a porosity and a saturation of a target layer; and smoothing a result and finally outputting a reservoir parameter inversion data volume.

The invention relates to a simple multi-parameter seismic inversion method for improving the precision and the reliability of the conventional pre-stack seismic inversion with the help of the seismic wave elastic impedance, thereby simultaneously extracting a variety of formation parameters. The steps are as follows: full wave logging information is utilized; an acoustic impedance AI and an elastic wave impedance EI are determined; a CMP gather is converted into an angle gather, and part of the angles are stacked; the conventional pre-stack elastic impedance inversion process is utilized to respectively carry out the AI and the EI inversion of cross-well measuring line of small angle stacked data and part of the stacked data of the middle incident angles; the channel calculation of the EI and the AI data which are obtained by inversion is carried out, thereby obtaining the seismic attributes which are closely related to the elastic density ratio, the lithology changes and the pore fluid ingredients; the reservoir lithology and the properties of the pore fluid are determined. The simple multi-parameter seismic inversion method only needs the seismic data of near and middle angles, and other parameters are obtained through the channel calculation of the relationship between the elastic density ratio and the acoustic impedance, thereby improving the calculation efficiency and being used in the pre-stack inversion of the seismic data obtained by the vast majority of the collection conditions.

The invention discloses a method for quantificationally predicting sandstone reservoir fluid saturation by combining a well and seism in geophysical prospecting for petroleum. The method comprises the following steps of: acquiring and processing seismic data and log data to obtain each parameter curve; respectively determining the relationships among the shale content, the porosity and an elastic parameter of the well; establishing prediction models of the shale content and the porosity; calculating a pore volume modulus and a dry rock volume modulus to establish a modulus prediction model; establishing an effective reservoir water saturation prediction model; performing prestack seismic inversion by utilizing prestack seismic trace gathers and the log data to obtain an inversion data volume of each elastic parameter; calculating the dry rock volume modulus to solve the pore volume modulus by the obtained elastic inversion volume; and solving the water saturation by using the pore volume modulus. In the method, prestack seismic data and the log data are fully utilized for quantificationally predicting reservoir saturation; and good geological effects on predicting oil and gas saturation are achieved.

The invention discloses a method for forecasting a carbonate reservoir based on forward modeling of a digital geological model, and is characterized by comprising the following steps: in petroleum geological exploration, through a field carbonate geological outcrop collecting and data processing technology and combination with an actually-measured geological section, establishing a three-dimensional digital geological model of an outcrop area, according to an outcrop rock speed analysis chart and a drill speed data, establishing a speed model of the carbonate reservoir with different physical properties on the basis of the three-dimensional geological model, carrying out two-dimensional forward modeling and three-dimensional forward modeling, carrying out offset horning process on earthquake forward modeling data so as to obtain three-dimensional offset data or a two-dimensional offset section of the earthquake forward modeling, establishing reflecting characteristics of different carbonate reservoirs according to response characteristics of the earthquake section, and forecasting the carbonate reservoir. According to the invention, qualitative forecasting of the carbonate reservoir can be realized without a regular earthquake inversion, a large amount of manpower and device resources are saved, reliability and precision of forecasting of the carbonate reservoir in the earthquake are effectively improved, exploration and development risk can be reduced, and benefit is increased.

The invention provides an igneous rock oil and gas exploration method and an igneous rock oil and gas exploration device. The method comprises the following steps of generating crater position and igneous rock lithofacies information according to the position of an igneous rock reservoir and characteristic information; generating geophysical reflection characteristic data according to seismic facies analysis, and determining a distribution range of advantageous lithofacies; calculating a stratigraphic strike-slip distance of a deep igneous rock mechanism according to a matching relation of target stratum lithofacies of a volcanic edifice on two sides of a fracture and a corresponding relation of igneous rocks of a middle-shallow layer on the two sides of the fracture; analyzing logging response data of the igneous rocks, and generating advantageous lithology distribution information and thickness data of the deep igneous rock mechanism through natural gamma seismic inversion; acquiring a development part of the fracture of the igneous rock reservoir by using means such as deep and shallow resistivity difference inversion; and generating igneous rock oil and gas reservoir information in the development part through cluster analysis of seismic attributes and two-phase media-based oil and gas detection. By the invention, the accuracy of exploring and predicting the igneous rock oil and gas reservoir and the drilling success rate can be improved.

A system and computer-implemented method for determining properties of a subsurface region of interest from seismic data is disclosed. An embodiment of the method performs full waveform inversion by non-linear model update to compute a velocity model. The method includes obtaining actual seismic data representative of the subsurface region and an initial earth property model for the subsurface region, performing forward modeling using the initial earth property model to create modeled seismic data with similar acquisition specifications as the actual seismic data, calculating a residual between the actual seismic data and the modeled seismic data in a time or transform domain, and inverting the residual to generate a model produced by non-linear model update components. The system includes a data source, user interface, and processor configured to execute computer modules that implement the method.

The invention provides a seismic inversion system and a seismic inversion method controlled by geologic facies. The seismic inversion system and the seismic inversion method controlled by the geologic facies comprises a geologic facies establishing module which establishes the geologic facies on a destination layer of a well point position, a seismic facies establishing module which establishes a seismic facies on a plane of the destination layer, a geologic facies constraint establishing module which establishes constraint to the geologic facies, a stochastic inversion module which chooses the number of constraint wells and conducts stochastic inversion controlled by the geologic facies, an analysis module which analyzes inversion data volume and further subdivides the geologic facies, and an output module which iterates repeatedly so as to obtain and output the three-dimensional inversion data volume. The seismic inversion system and the seismic inversion method controlled by the geologic facies solves the problem that due to the fact that geological sedimentary background and regularity in an inversion work area are not considered by the existing inversion method, and inversion results are often horizontally different from geological sedimentary regularity cognition. The seismic inversion system and the seismic inversion method controlled by the geologic facies has the advantages of being capable of accurately depicting oil deposit on the basis of control of the geologic facies.

According to a preferred aspect of the instant invention, there is provided herein a system and method for using both a temporal zone of seismic data and conditioned amplitude spectra thereof to determine the underlying layer sequence. The instant invention is suitable both for determining layer positions and layer impedance magnitudes, that best describes the geologic sequence sampled by a band limited seismic source wavelet as reflected from the zone.

The invention discloses a lithofacies constrained reservoir physical property parameter inversion method and device. The lithofacies constrained reservoir physical property parameter inversion method comprises the steps of establishing a target inversion function based on lithofacies constraint according to a Bayes inversion frame and lithofacies information; introducing the lithofacies information to establish a statistical rock physical lithofacies model; utilizing a stochastic simulation technology to produce an elastic parameter and reservoir physical property parameter training sample set including the lithofacies information based on the statistical rock physical lithofacies model; inputting pre-stack seismic inversion result data and lithofacies data, and utilizing the training sample set to solve the target inversion function based on the lithofacies constraint. The lithofacies constrained reservoir physical property parameter inversion method and device uses the lithofacies information as inversion constraint information, enables an inversion principle to be more rigorous and enables the inversion process to be more reasonable by adding the lithofacies constraint and can greatly decrease multiple solutions of an inversion result. The derived target inversion function includes the lithofacies information, the solving process is more targeted, the result is more reliable, and the favorable position of a reservoir can be accurately recognized.

The invention discloses a logging and seismic data fusion-based formation lithology inversion method and belongs to the seismic inversion field. The method includes the following steps that: a loggingwave impedance data body and a logging lithological data body are established according to a logging curve; a seismic wave impedance data body is established according to seismic data and the loggingwave impedance data body; a seismic lithological data body is established according to the seismic wave impedance data body; the logging lithological data body and the seismic lithological data bodyare compared with each other on the basis of a neural network algorithm, so that a lithological fusion parameter body can be obtained; and the lithological fusion parameter body is used to perform formation section-based weighted fusion on the logging lithological data body and seismic lithological data body, so that an inversion lithologic body can be obtained. The inversion lithologic body obtained by the method can improve the longitudinal resolution of seismic lithological prediction and is of great significance for the prediction of formation lithological prediction.

The present invention relates to a seismic facies control-based sedimentary microfacies recognition method. The method includes the following steps that: 1) logging information is normalized; 2) fine horizon calibration is performed; 3) a model framework is determined; 4) a low frequency model is established; 5) a seismic data impedance value and a formation reflection coefficient are obtained, if synthetic trace data are in optimal matching with an actual seismic data trace, and drilling impedance is in optimal matching with seismic data impedance, and the method shifts to step 6), otherwise, the method shifts to the step 3); 6) well seismic constraint inversion is performed, a wave impedance inversion data body is obtained; 7) the top and bottom of a reservoir are traced and explained, with the top reflection layer and bottom reflection layer of the reservoir adopted as control surfaces, interlayer attributes are extracted from the inversion data body; and 8) seismic attributes are utilized to constrain the boundaries of sedimentary microfacies, and the spread of the sedimentary microfacies is described. According to the method, the logging information is adopted to constrain seismic inversion, and therefore, the resolution of an inversion result can be improved, the sedimentary microfacies of a target interval can be well depicted, the planar distribution of a thin sand layer can be predicted, and a basis can be provided for well location deployment.

During a drilling operation, measured data from the drilling operation may be received with a panistic inversion and risk estimate module. The panistic inversion and risk estimate module may generate a plurality of mathematical solutions from a panistic inversion that uses the measured data and one or more earth models. The one or more earth models having various parameters may be selected prior to drilling and/or while the drilling operation occurs. For each solution of the plurality of mathematical solutions generated from the panistic inversion, the panistic inversion and risk estimate module may determine if the measured data exceeds one or more probability risk thresholds associated with the drilling operation. If the measured data exceeds the probability risk threshold associated with the drilling operation, then the panistic inversion and risk estimate module may generate an alert.

The invention discloses a method for improving the capability of a seismic inverted data prediction storage layer, comprising the steps of: carrying out well wave impedance or speed inversion on seismic data in a work area so as to generate inverted data; determining the length of an initial time window, the sliding step length of the time window, the numerical value amplitude error achieved by curve data according to requirements in the time window, and judgment control parameters of low and high points in the time window; generating a searching time window for the wave impedance or the speed inverted data; generating a self-adaptive time window according to the numerical value amplitude error achieved by the curve data in the time window according to the requirements; computing the statistic of inversion channel data in the self-adaptive time window and the change rate of the numerical value at each sampling point so as to determine relatively low points; generating lower lines corresponding to the inversion channel data by selecting a reasonably and relatively low point in the relatively low points and carrying out interpolation and extrapolation on the reasonably and relatively low point; and carrying out relative difference output on the seismic inverted data via the low lines of the inversion channel data and determining the lithology or the stored optimum relative difference recognition value through adjusting a sectional color code under the contrast of borehole materials.

The invention relates to a fluid elastic impedance inversion technology. The technology comprises the following steps: transforming interface information of a subsurface layer into elastic parameter information reflecting earth layer information by seismic inversion, electing the most sensitive elastic parameters by sensitivity analysis of reservoir fluid, and performing corresponding reservoir prediction and fluid identification; taking fluid parameters in Gassmann inversion theory as a starting point and a reflection coefficient formula of a porous elastic medium proposed by Russell as a basis, and directly extracting a fluid factor f, a shear modulus Mu showing a rock matrix structure and a density parameter Rho by computing FEI inversion results. The technology can help obtain ideal fluid identification effect.

The invention belongs to the technical field of sandstone-type uranium deposit exploration, and particularly discloses a sand body reorganization method in sandstone-type uranium deposit exploration. The method includes the following steps that (1) pure wave data of a seismic processing section are collected; (2) logging data of a drilling well nearby the seismic section are collected, and the abnormal contrast value of density and the abnormal contrast value of sound waves are calculated; (3) moving average processing is conducted on density data and sound wave data; (4) a seismic inversion calculation initial model is established through the density data, the sound wave data and the logging data after moving average processing in the step (3); (5) inversion calculation is carried out on wave impedance data of the seismic section through an inversion method based on the model, and the wave impedance data of the seismic section are acquired; (6) sand bodies in a sandstone-type uranium deposit area are determined according to the wave impedance data acquired in the step (5). By means of the sand body reorganization method in sandstone-type uranium deposit exploration, the development condition and the distribution feature of the sand bodies in sandstone-type uranium deposit exploration can be recognized accurately, rapidly and economically.

The invention discloses a seismic inversion reservoir stratum forecasting method for an overthrust-containing complex structure, and relates to the technical field of a method for forecasting reservoir strata in oil-gas exploration and development. The method comprises the following steps of: (1) extracting seismic wavelets; (2) demarcating a geologic horizon by well logging data, and corresponding the time-depth relation of the well logging data and seismic data one by one; (3) importing a seismic interpretation horizon and a seismic interpretation fault, and establishing an initial model of seismic inversion by an overthrust-containing modeling method; (4) calculating an inversion result by a model-based inversion algorithm; and (5) performing seismic interpretation on the seismic inversion result. When the method is used, the seismic inversion of the reservoir strata of the overthrust-containing complex structure makes the breaking points distinct and the heading side data of the fault credible and increases the forecastable area, and the problem that the fault area of the seismic inversion reservoir stratum forecasting of the overthrust-containing complex structure in the conventional seismic exploration is difficult to interpret is solved.

The invention discloses an unconformity strong-reflection self-adaptive separation method based on matching pursuit. Firstly seismic data is leveled along an unconformity layer interpretation result, and overlapped to acquire an overlapped seismic trace, phase and frequency at the maximum instantaneous amplitude are selected through calculating by using three instantaneous attributes, and a waveform width parameter is scanned, so that the best matched atom is acquired. A spectral factorization method is introduced, the best waveform atom is acquired by matching pursuit to be mutually correlated with original seismic records, strong reflection is information is extracted and separated from the original seismic records, and thus the seismic records highlighting effective reflection of reservoirs are acquired. The method provided by the invention is high in computation efficiency and strong in stability, and provides an effective data base for subsequent reservoir prediction and fluid identification based on prestack seismic inversion.

The invention discloses a seismic inversion method and system based on generalized total variation regularization, so as to solve the problem that step effects are generated inside a formation when the existing seismic inversion technology adopts total variation regularization. The method uses the characteristic that generalized total variation not only uses first-order partial derivative information of a to-be-inverted parameter but also uses second or higher-order information, the formation interface can be clearly expressed and the step effects inside the formation can also be weakened; besides, a phenomenon that a product of a wavelet matrix, a difference matrix and the natural logarithm of the to-be-inverted parameter can be used to be converted to the convolution among a convolutionkernel corresponding to the wavelet matrix, a convolution kernel corresponding to the difference matrix and the natural logarithm of the to-be-inverted parameter is found out, the convolution operation in a time domain is converted to point multiplication operation in a frequency domain, and the inversion speed is greatly improved; a reflection coefficient does not need to be inverted firstly, anddirect inversion is carried out in the frequency domain to obtain the to-be-inverted parameter; and the method and the system are applicable to the technical field of seismic exploration.

The invention provides an azimuth pre-stack seismic attribution decoupling extraction method. Based on a horizontal fracture heterogeneous stratum hypothesis, isotropy gradient attribute and anisotropy gradient attribute in different symmetry planes are decoupled and extracted in a concentrated manner from shale work area multi-azimuth pre-stack angle gathers. The specific steps are that: firstly fully analyzing azimuthal anisotropy characteristics caused by horizontal fractures in a shale work area, deriving two AVO approximate equations of azimuthal anisotropy caused by the horizontal fractures, extracting AVO intercept attribute and azimuth AVO gradient attribute; then, based on the extracted azimuth AVO gradient attribute, decoupling and extracting isotropy gradient attribute of the work area and anisotropy gradient attribute in different symmetry planes; and finally, using the extracted anisotropy gradient attribute in different symmetry planes to identify underground horizontal fracture positions and anisotropy intensity thereof, so as to effectively guide subsequent seismic inversion operation. The technology can enhance reliability of identifying shale horizontal fracture developing positions, and improves precision of shale reservoir prediction and fluid identification.