Abstract: A method for creating a modified realization of a geostatistical model of a subterranean hydrocarbon reservoir is described, which may be used in a history matching process. The modified realization is based on a current realization which is a function of a first uniform random number field. At least one further uniform random number field Ui is created and a linear combination made of the first uniform random number field and the further uniform random number field or fields Ui, together with combination coefficients ri, to derive a modified non-uniform random number field V. A uniform score transformation procedure is then performed, e.g. using an empirical cumulative distribution function, on the modified non-uniform number field V, to derive a modified uniform random number field Umod. A modified realization of the model can then be derived from the uniform random number field Umod.

Abstract: The invention is a method for real-time updating of a geological model using dynamic data while maintaining the coherence thereof with static observations. An initial set of reservoir property maps, obtained from stochastic simulations of a random function, are available. Parameters providing new realizations of the random function when applied to the set are selected. New maps are created using initial values of the parameters. As soon as new dynamic data are available, the parameters are modified to reduce a difference between the simulated data for perturbed models and the measured data. Finally, the reservoir is developed using a modified development scheme to account for the deformed maps.

Abstract: A system can include a framework for scenario-based assessment of a physical environment; and an integrator that includes an analyzer component for identifying an analyzer as one of a plurality of identifiable analyzers, a scenario component for framework and analyzer interactions for a scenario, and a results component for framework and analyzer interactions with respect to analyzer results for the scenario. Various other apparatuses, systems, methods, etc., are also disclosed.

Abstract: Embodiments of a method for implementing a finite difference time domain modeling with multiple APCs are disclosed herein. The disclosed methods and systems overcome the memory capacity limitation of APCs by having each APC perform multiple timesteps on a small piece of the computational domain or data volume in a APC queued manner. The cost of transferring data between host and compute accelerator can then be amortized over multiple timesteps, greatly reducing the amount of PCI bandwidth required to sustain high propagation speeds. The APC queued nature of the algorithm achieves linear scaling of PCI throughput with increasing number of APCs, allowing the algorithm to scale up to many dozens of APCs in some embodiments.

Abstract: Equipment associated with a gelled fluid may be manipulated based on a stress response of the gelled fluid as determined by a gel microstructure destruction model comprising an equivalent work integral function. Further, systems and devices may be configured to manipulated equipment associated with a gelled fluid based on a stress response of the gelled fluid as determined by a gel microstructure destruction model comprising an equivalent work integral function.

Abstract: High performance computing (HPC) and grid computing processing for seismic and reservoir simulation are performed without impacting or losing processing time in case of failures. A Data Distribution Service (DDS) standard is implemented in High Performance Computing (HPC) and grid computing platforms, to avoid the shortcomings of current Message Passing Interface (MPI) communication between computing modules, and provide quality of service (QoS) for such applications. QoS properties of the processing can be controlled.

Abstract: A method having application for petroleum exploration or geological storage of generating a mesh of a faulted underground medium, comprising generating a hex-dominant mesh from faults and horizons in a form of a 3D triangulated surfaces. Each 3D triangulated surface is converted to a 2D triangulated surface onto which the faults are projected by an isometric unfolding technique. A regular two-dimensional grid pattern is generated for each 2D triangulated surface. The faults are accounted for by deforming quadrilaterals of the grid pattern intersected by projected faults. The deformed regular grid pattern is then converted to a 3D gridded surface and each quadrilateral which is crossed by a fault is converted into two triangles at a level of a diagonal. Finally, after iterating for all the 3D triangulated surfaces, the mesh is generated by creating links between the nodes of neighboring three-dimensional gridded surfaces with respect to the faults.

Abstract: Method for speeding up iterative inversion of seismic data (106) to obtain a subsurface model (102), using local cost function optimization. The frequency spectrum of the updated model at each iteration is controlled to match a known or estimated frequency spectrum for the subsurface region, preferably the average amplitude spectrum of the subsurface P-impedance. The controlling is done either by applying a spectral-shaping filter to the source wavelet (303) and to the data (302) or by applying the filter, which may vary with time, to the gradient of the cost function (403). The source wavelet's amplitude spectrum (before filtering) should satisfy D(f)=fIp(f)W(f), where f is frequency, D(f) is the average amplitude spectrum of the seismic data, and Ip(f) is the average amplitude spectrum for P-impedance in the subsurface region (306,402) or an approximation thereof.

Abstract: Parametric Bayesian Updating method is described for attribute importance measures. AIM is a quantitative measure of the relative importance of multiple attributes used in a Bayesian Updating parametric multivariate modeling approach. The AIM is a function of the correlation coefficients between the attributes themselves and the attributes with collocated target variable. The importance calculation is straightforward, repeatable, and objective.

Abstract: High performance computing (HPC) and grid computing processing for seismic and reservoir simulation are performed without impacting or losing processing time in case of failures. A Data Distribution Service (DDS) standard is implemented in High Performance Computing (HPC) and grid computing platforms, to avoid the shortcomings of current Message Passing Interface (MPI) communication between computing modules, and provide quality of service (QoS) for such applications. QoS properties of the processing can be controlled.

Abstract: Methods of analyzing fluid flow in a formation include defining physical boundaries of a porous geological formation reservoir and parameters related to a process of injection of fluid over a period of time, and configuring a reservoir simulator that characterizes transport of the fluid as solute within the physical boundaries of the reservoir in accordance with the fluid injection process. The reservoir simulator utilizes at least one upscaled equation describing advective transport for the solute. Output of the simulator may be viewed. The parameters related to the injection process including one or more of an injection rate, a location of injection, and a time length of injection can be optimized.

Abstract: Simulation system and method for a reservoir represented by a model having a plurality of matrix nodes, a plurality of fracture nodes, a fracture zone and a fracture-free zone are described. One embodiment includes computer-implemented steps of, for each of a plurality of matrix nodes in interconnected zones, characterizing the matrix nodes as dual matrix nodes or non-dual matrix nodes. Dual matrix nodes may be treated as a block and eliminated, after which the coefficient matrix and RHS vector for the model are updated. In-fill patterns between and among fracture nodes and non-dual matrix nodes resulting from the elimination are determined. For non-dual matrix nodes, the nodes are merged to a fracture grid, after which the coefficient matrix and RHS vector for the model are updated accordingly. The resultant linear system is linearly solved, and backsolving is performed for any eliminated dual matrix nodes.

Abstract: A method includes obtaining a model associated with production of natural gas from a well, where the well has a choke valve that controls flow of material including natural gas from the well. The method also includes identifying, using the model, a solution that increases an amount of natural gas obtained from the well over a specified time horizon. In addition, the method includes adjusting operation of the choke valve based on the identified solution. The model could be generated using geological data associated with the well and/or historical data associated with natural gas production from the well. A natural gas reservoir can be modeled as a continuous stirred bed with a rock or shale void fraction using mass or volumetric unit balances. Gas content versus pressure for the well can be plotted, and Langmuir adsorption parameters for the well can be identified using the plotted gas content versus pressure.

Abstract: Method and system is described for modeling one or more strength properties of a subsurface volume. The method provides an enhanced process for upscaling to simplify data in a manner that accounts for problems with conventional techniques. The method involves simplifying the petrophysical data and/or layers to provide an upscaling approach that accounts for the influences on the strength properties. The properties may then be utilized to enhance a subsurface model and used to enhance hydrocarbon recovery.

Abstract: Systems, methods, and machine-executable coded instruction sets for associating map, enterprise, and geostatistical data for mapping and otherwise analyzing properties of geological deposits, resource recovery and other enterprises, and geostatistical data.

Abstract: A method of estimating flow properties of an earth formation includes: selecting a grid block representing a region of the earth formation, the region including at least one of an area and a volume of the earth formation, the grid block including a plurality of grid cells and having an orientation defined by grid axes; and calculating a fluid flow model of the region. Calculating the model includes: estimating a principal flow direction for each grid cell; adjusting the orientation of the grid block based on the principal flow direction; and calculating fluid flow parameters in each grid cell to generate the fluid flow model.

Abstract: An embodiment of a method for constructing a fracture network includes: receiving seismic data collected from a stimulation operation in an earth formation, the seismic data including seismic event data including a first seismic event associated with a first time increment and a second seismic event associated with a subsequent second time increment; and constructing a fracture network model. The model is constructed by: constructing an initial portion of the model based on the first seismic event; and subsequently updating the initial portion of the model based on the second seismic event.

Abstract: Rock physics guided migration is disclosed to enhance subsurface three-dimensional geologic formation evaluation. In one embodiment, a geologic interpretation is generated based on a seismic data volume. Sets of compaction and acoustic formation factor curves are generated, and these are combined into a set of velocity-relationship curves. A pore pressure is derived and used to establish a pore pressure state. A rock physics template is then generated utilizing the derived information. This rock physics template can be used to refine geologic formation evaluation with any suitable form of migration technique.

Abstract: Device and method for smoothing an original velocity model of a given subsurface such that a travel-time through the given subsurface is preserved. The method includes receiving the original velocity model, wherein the original velocity model has a set of model parameters that determine a given parameterization and the original velocity model has velocity discontinuities at various depths; selecting a sub-set of model parameters of the given parameterization; converting the selected sub-set of model parameters to composite parameters; smoothing with a processor the composite parameters by applying a convolutional filter (g) such that velocity moments are preserved at the velocity discontinuities; and generating a smooth velocity model by converting the smoothed composite parameters into a smoothed sub-set of model parameters.

Abstract: Systems and methods for diagnosing production problems in oil field operations are provided. A first video monitor displays an oil field diagnosis process flow chart that includes selectable objects such as Review Well Test Differences, Review Sliders, Review Bad Actors, and Perform Steam Flood Performance Check. Each selectable object is associated with one or more incompatible domain-specific software applications. One or more of the selectable objects are selected and one or more additional video monitors display reports extracted by a middle-ware software code segment layer from the associated domain-specific software applications. Oil wells having production problems are listed and problem oil wells are displayed on an oil field map. Any commonalities among the displayed problem oil wells indicative of a common cause of the production problems are visually identified. Work is scheduled in the associated domain-specific software applications sufficient to remedy the common cause.

Abstract: Methods and systems for making decisions related to the operation of a hydrocarbon well include characterizing effective production capacity of a reservoir over space and time based at least in part on a reservoir potential and a near-well capacity; determining an optimized well potential over space and time relative to the characterized effective production capacity using a well model of a simulated well accessing the reservoir, which may be determined based at least in part on an objective function that considers at least one of a plurality of decision-making factors, such as one or more of operations costs, operational risks, and modeled production rates over the life of the well; and determining at least one well operating plan component that can be incorporated into a well operating plan to provide the optimized well potential in a well accessing the reservoir.

Abstract: A method and systems for dynamically planning a well site are provided herein. The method includes generating, via a computing system, a three-dimensional model of a hydrocarbon field including a reservoir. The method also includes determining a location for a well site based on the three-dimensional model and determining reservoir targets for the determined location and a well trajectory for each reservoir target. The method also includes adjusting the location for the well site within the three-dimensional model and dynamically adjusting the reservoir targets and the well trajectories based on the dynamic adjustment of the location for the well site. The determination and the dynamic adjustment of the location, the reservoir targets, and the well trajectories for the well site are based on specified constraints. The method further includes determining a design for the well site based on the dynamic adjustment of the location, the reservoir targets, and the well trajectories for the well site.

Abstract: Methods for constraining basin models to forecast the presence and maturity of hydrocarbon in a basin. The method involves determining a Curie depth at a location at the basin, constraining basin models to match the Curie depth at the location and determining the presence of hydrocarbon in the basin based on the basin models constrained by Curie depth.

Abstract: This disclosed subject matter is generally related to methods for characterizing two-dimensional (2D) and three-dimensional (3D) samples to determine pore-body and pore-throat size distributions and capillary pressure curves in porous media using petrographic image analysis. Input includes high-resolution petrographic images and laboratory-derived porosity measurements. Output includes: (1) pore-body and pore-throat size distributions, and (2) simulated capillary pressure curves for both pore bodies and pore throats.

Abstract: This subject disclosure describes methods to build and/or enhance 3D digital models of porous media by combining high- and low-resolution data to capture large and small pores in single models. High-resolution data includes laser scanning fluorescence microscopy (LSFM), nano computed tomography (CT) scans, and focused ion beam-scanning electron microscopy (FIB-SEM). Low-resolution data includes conventional CT scans, micro computed tomography scans, and synchrotron computed tomography scans.

Abstract: A system and method for characterizing uncertainty in a subterranean fracture network by obtaining a natural fracture network, obtaining dynamic data, simulating hydraulic fracturing and microseismic events based on the natural fracture network and the dynamic data, generating a stimulated reservoir volume (SRV), and quantifying the uncertainty in the SRV. It may also include narrowing the uncertainty in the SRV through the use of Design of Experiment methods and characterizing the SRV using static and/or dynamic data.

Abstract: A method for modeling a migration of hydrocarbon fluids. The method may include decomposing, by operation of a processor, a domain of a basin model to produce a first plurality of cells having a permeability below a threshold value and a second plurality of cells having a permeability above the threshold value. A first migration analysis may be performed to analyze a relatively slow migration starting in the first plurality of cells. A second migration analysis may be performed to analyze a relatively faster migration starting m the second plurality of cells.

Abstract: A system and method for processing and combining data from multiple curves or data-sets in oil field operations based upon a common index. The multiple input curves are combined to form an input vector. The input vector is aligned on the common index, without any values in the curve or data-set being changed. The input vector is then processed to ensure that all curves have values for all index values by interpolation. The input vector may be further processed to create a fixed step increment. An output vector is formed by operation of a set of formulas on the interpolated input vector.

Abstract: A computer-implemented system, method, and software are provided for solving linear systems of equations arising in reservoir simulation. A linear system of fluid flow equations, including a plurality of unknown variables, is provided that represents fluid flow properties in a geological formation of a subterranean reservoir. Block diagonal scaling is applied to the linear system of fluid flow equations. Threshold incomplete lower-upper approximate factorization is applied to obtain a preconditioning matrix, which can be used to iteratively solve unknown variables associated with the system of fluid flow equations. Preconditioning can be used directly as part of a preconditioned Krylov subspace method or alternatively as a 2nd stage preconditioner in a CPR algorithm.

Abstract: The present invention relates to a method (EXP) for exploiting a subterranean medium by means of a fractured reservoir model. The fractured reservoir model is matched (CAL) for a set of chosen wells (CHO), for which the measured dynamic data (DD) correspond to the estimated dynamic data by means of an equivalent transmissivity model (MOD).

Abstract: Predicting gas saturation of a formation using neural networks. At least some of the illustrative embodiments include obtaining a gamma count rate decay curve one each for a plurality of gamma detectors of a nuclear logging tool (the gamma count rate decay curves recorded at a particular borehole depth), applying at least a portion of each gamma count rate decay curve to input nodes of a neural network, predicting a value indicative of gas saturation of a formation (the predicting by the neural network in the absence of a formation porosity value supplied to the neural network), and producing a plot of the value indicative of gas saturation of the formation as a function of borehole depth.

Abstract: Systems, methods, and instructions encoded in a computer-readable medium can perform operations related to simulating subterranean fracture propagation. A subterranean formation model representing rock blocks of a subterranean formation is received. The subterranean formation model is used to predict a response of each rock block to one or more forces acting on the rock block during an injection treatment for the subterranean formation. The predicted responses of the rock blocks may include, for example, a fracture, a rotation, a displacement, a dilation of an existing fracture, and/or another type of response. In some implementations, an injection treatment may be designed for a subterranean formation based on the predicted response of the rock blocks.

Abstract: A method for modeling flow properties over a series of time increments of a reservoir in an earth formation having a plurality of fractures is disclosed. The method includes: building a three-dimensional stress field representing stresses in the reservoir; building a three-dimensional discrete fracture network (NFM) having fracture flow properties using information obtained from a tool or changes to the stress field; running a flow simulation of the reservoir for a time increment using the NFM to model the flow properties of the reservoir for that time increment; computing a latest change in the three-dimensional stress field from the flow simulation; and incrementing the time increment and iterating the building the NFM using the latest change in the stress field, the running of the flow simulation using the latest NFM, and the computing a latest change in the stress field from the latest running of the flow simulation.

Abstract: Method for speeding up iterative inversion of seismic data (106) to obtain a subsurface model (102), using local cost function optimization. The frequency spectrum of the updated model at each iteration is controlled to match a known or estimated frequency spectrum for the subsurface region, preferably the average amplitude spectrum of the subsurface P-impedance. The controlling is done either by applying a spectral-shaping filter to the source wavelet (303) and to the data (302) or by applying the filter, which may vary with time, to the gradient of the cost function (403). The source wavelet's amplitude spectrum (before filtering) should satisfy D(f)=fIp(f)W(f), where f is frequency, D(f) is the average amplitude spectrum of the seismic data, and Ip(f) is the average amplitude spectrum for P-impedance in the subsurface region (306,402) or an approximation thereof.

Abstract: A system for resource usage optimization employs an automatically controlled sensor suite providing data to a computer system for the analysis of spatial relationships of the sensors and resources. A control module incorporates an interactive logic, in an exemplary embodiment of well-stream coupled dynamic or game theory engines, operating in conjunction with the spatial data processing algorithms, GIS in an exemplary embodiment, receives as an input an objective function set for the use of the resource and constraint sets which are then monitored by the sensor suite. Incoming data is compared to the constraint sets and upon impact to any of the elements of the objective function set, creates a report/alarm for action or to trigger a corrective action.

Abstract: A method for transforming seismic surface waves into depth profiles of dynamic properties of the soil such as the soil shear modulus or wave velocity or wave attenuation. The invention uses seismic data recorded preferably with a plurality of sources and receivers with a two-stage inversion approach. First, variations in surface-wave waveforms are decomposed (303) into surface-consistent transfer functions preferably for each source, each receiver, and each small region (301) of the surface. Then the transfer functions for each region are inverted (308) to determine soil properties or near-surface properties (such as the shear modulus) as a function of depth. The method can solve for the complex multi-mode nature of the surface waves for a media with both vertical and lateral changes in properties. Errors and limits in resolution for traditional methods from misidentification of ground roll modes or from assuming laterally uniform soil properties are avoided.

Abstract: A robust well trajectory planning and drilling or completion planning system that integrates well trajectory optimization and well development planning optimization so that optimized solutions are generated simultaneously. The optimization model can consider unknown parameters having uncertainties directly within the optimization model. The model can systematically address uncertain data and well trajectory, for example, comprehensively or even taking all uncertain data into account. Accordingly, the optimization model can provide flexible optimization solutions that remain feasible over an uncertainty space. Once the well trajectory and drilling or completion plan are optimized, final development plans may be generated. Additionally, the optimization model may generate and implement modified well development planning and modified well trajectory in real-time.

Abstract: A method for correlating data predicted by a processor physics-based geologic model to describe a subsurface region with obtained data describing the subsurface region. Data is obtained describing an initial state of the subsurface region. Data describing a subsequent state of the subsurface region is predicted. The predicted data is compared with the obtained data taking into account whether the obtained data or the predicted data represent a discontinuous event. A sensitivity of the predicted data is determined if the predicted data is not within an acceptable range of the obtained data. The data describing the initial state of the subsurface region is adjusted based on the sensitivity before performing a subsequent iteration of predicting data describing the subsequent state of the subsurface region. A representation of the subsurface region based on the data describing the subsequent state of the subsurface region is outputted.

Abstract: A technique provides a methodology for improving surveys of subterranean regions. The methodology comprises estimating macro anisotropy and an intrinsic or micro anisotropy of an overburden. A surface electromagnetic survey is conducted, and the data from the survey is inverted based on or including information gained from estimating the macro anisotropy and/or intrinsic anisotropy. A processor system can be used to conduct the inversion with the adjustments for anisotropy to improve the information provided by the survey.

Abstract: Disclosed herein is a method of servicing a wellbore comprising the steps of preparing a dry cement blend comprising a base cement and a crystalline component wherein the dry cement blend is based on an initial dry cement blend formulation, obtaining a diffraction pattern of a sample of the dry cement blend, generating a model diffraction pattern, refining the model diffraction pattern using a structural refinement method, determining the type and amount crystalline components present in the dry cement blend, generating a final dry cement blend formulation, and comparing the initial dry cement blend formulation to the final dry cement blend formulation.

Abstract: Modeling and triggering safety barriers. At least some of the illustrative embodiments are a non-transitory machine-readable storage medium includes executable instructions that, when executed, cause one or more processors to model, using one or more models, safety barriers in one or more drilling rigs based on drilling rig safety barrier data. The processors are further caused to identify, based on the one or more models, a first impending invalidation of a first safety barrier. The processors are further caused to initialize, triggered solely by the instructions, a second safety barrier based on the impending invalidation.

Abstract: Systems, methods, and instructions encoded in a computer-readable medium can perform operations related to simulating injection treatments applied to a subterranean formation from multiple well bores in the subterranean formation. A subterranean formation model representing rock blocks of a subterranean formation is received. Information on multiple injection treatments for multiple well bores in the subterranean formation is received. The subterranean formation model and the information on the injection treatments is used to predict a response of each of the rock blocks to forces acting on the rock block during the injection treatments. The injection treatments may include, for example, multiple fracture treatments for simultaneous application to the subterranean formation. In some implementations, injection treatments may be designed for a multiple-well bore system based on the predicted response of the rock blocks.

Abstract: Implementations of discontinuity detection are described. In one possible embodiment, information associated with a computer-generated model is accessed. A location associated with a feature in the model can be reviewed for possible discontinuity properties by comparing an orientation associated with the location to an orientation of a true normal to the feature associated with a specific point nearby the location. In one possible aspect, if the orientation associated with the location and the true normal are within a given range of one another, the location can be flagged as a possible discontinuity in the feature.

Abstract: Method for reducing artifacts in a subsurface physical properties model (120) inferred by iterative inversion (140) of geophysical data (130), wherein the artifacts are associated with some approximation (110) made during the iterative inversion. In the method, some aspect of the approximation is changed (160) as the inversion is iterated such that the artifacts do not increase by coherent addition.

Abstract: In one example, formation fluid flow through a fractured reservoir is simulated using conductivity of aged proppants. A first conductivity profile is received for a proppant. The first conductivity profile describes an ability of the proppant to permit formation fluid flow through a fracture network under reservoir conditions in a fractured reservoir that includes the proppant in the fracture network. The proppant is aged for a duration under the reservoir conditions of the fractured reservoir over the duration. After the duration, a second conductivity profile for the aged proppant is determined. An adjusted conductivity profile for the proppant is determined based on the first conductivity profile and the second conductivity profile. The adjusted conductivity profile is provided as an input conductivity profile for the proppant. The reservoir simulator simulates formation fluid flow through the fractured reservoir using the input conductivity profile.

Abstract: High performance computing (HPC) and grid computing processing for seismic and reservoir simulation are performed without impacting or losing processing time in case of failures. A Data Distribution Service (DDS) standard is implemented in High Performance Computing (HPC) and grid computing platforms, to avoid the shortcomings of current Message Passing Interface (MPI) communication between computing modules, and provide quality of service (QoS) for such applications. QoS properties of the processing can be controlled.

Abstract: A method of developing a petroleum reservoir, wherein a facies map representative of the reservoir is constructed from petrophysical property maps. A grid cell visiting order is defined by selecting the visiting order that first passes through the cells where the facies are the most discriminated. Then, in each cell i, according to the visiting order, and for various facies values k, the likelihood defined by the probability of obtaining in cell i the values of observed petrophysical properties is calculated, knowing that the facies in cell i is facies k, and knowing on the one hand already identified facies values V*<i and, the values of the petrophysical properties of the previously visited cells. The facies value that maximizes the likelihood in cell i is associated with each cell i of the grid.

Abstract: Method for predicting the effect of microbes injected into an oil-bearing reservoir which is capable of being represented by a first computer-generated grid including a first plurality of grid blocks. Measurement data representing the effect of injecting the microbes into a multiple coreflood apparatus is received. The multiple coreflood apparatus has material samples indicative of a rock formation associated with the oil-bearing reservoir, the samples being capable of being represented by a second computer-generated grid having a second plurality of grid blocks, the samples being representative of different regions of the reservoir and being connected such that microbes injected into the first sample are able to flow to the second sample. Data received is input into a computer-implemented reservoir model which simulates the effect of microbe injected in relation to the second grid. The reservoir model generates data indicating the effect of injecting the microbes into the multiple coreflood apparatus.

Abstract: A method of developing a petroleum reservoir from a flow model constrained by production data and seismic data is disclosed. It is used to define a development scheme and to start or continue the reservoir development. Production data and seismic data associated with a fine grid are acquired during the development of the reservoir. Production data, as well as pressure and saturation values, are simulated in each cell of the flow model. A pressure value and a saturation value are assigned to each cell of the fine grid. A pressure equation is therefore solved locally on the fine grid and the saturations are calculated by writing the continuity of the phase flows between neighboring lithofacies, the conservation of the pore volume and the conservation of the phase volume. The maps obtained are then used to simulate seismic data.

Abstract: Disclosed is a process for characterising the evolution of a reservoir over a time lapse comprising the steps of: providing a base and a plurality of monitor surveys of the reservoir, each having a set of seismic traces at different times; deriving an optimal regularization weight-map from a combination of at least three surveys; and using the optimal regularization weights to invert and obtain an improved time lapse seismic image between pairs of seismic surveys.