Abstract: A model for predicting fracturing in shale can minimize surface disruption, protect groundwater, maximize efficiency of hydraulic fracturing, and manage fluids used in unconventional gas development. The model provides a more comprehensive understanding of the geological, geophysical, and geomechanical properties of shales and imbeds these properties in geomechanical computer simulations to predict both the reservoir performance from the fracturing, and the associated microseismic events generated by fracturing. Since the geological and geophysical properties can be estimated from surface seismic, well logs, and geologic concepts with regional context; the performance of the fracturing can be predicted and optimized. Since the microseismic events can be predicted with the model, the simulations can be verified and the model can be updated to be consistent with the observed microseismic.

Abstract: A model for predicting fracturing in shale can minimize surface disruption, protect groundwater, maximize efficiency of hydraulic fracturing, and manage fluids used in unconventional gas development. The model provides a more comprehensive understanding of the geological, geophysical, and geomechanical properties of shales and imbeds these properties in geomechanical computer simulations to predict both the reservoir performance from the fracturing, and the associated microseismic events generated by fracturing. Since the geological and geophysical properties can be estimated from surface seismic, well logs, and geologic concepts with regional context; the performance of the fracturing can be predicted and optimized. Since the microseismic events can be predicted with the model, the simulations can be verified and the model can be updated to be consistent with the observed microseismic.

Abstract: A method for evaluating measured electromagnetic (EM) data relating to a subsurface region, comprising the steps of: (a) specifying alternative models of the region in terms of input parameters with uncertainty; (b) receiving the measured EM data and an estimated error; and (c) carrying out a Bayesian inversion on the measured data using each of the alternative models to attribute a probability to each model on the basis of the measured data and estimated error. The method allows physical measurements with error to be translated into fundamental parameters which can be used to assess business risk and uncertainty for making decisions, and also provides for parameters and models which can typically be directly estimated by a geoscientist on a coarse spatial grid to be used as an input, and validated using the measured data with error.

Abstract: A method for evaluating measured electromagnetic (EM) data relating to a subsurface region, comprising the steps of: (a) specifying at least one model of the region in terms of fundamental parameters with uncertainty, using a fundamental inversion grid; (b) receiving the measured EM data and an estimated error; (c) translating the fundamental parameters of the model to meta parameters of the region and to a computational grid suitable for forward modelling and comparison to the measured EM data, using relationships with uncertainty; and (d) carrying out a Bayesian inversion using the measured data and estimated error to produce an output comprising fundamental parameters of the region on the fundamental inversion grid with uncertainty.

Abstract: 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.

Abstract: A method for determining impedance coefficients of a seismic trace comprises determining reflection coefficients of the seismic trace, for example using a sparse spike inversion, integrating the reflection coefficients with respect to time to obtain impedance coefficients, and filtering the impedance coefficients by applying a low-cut window filter. The window size and/or shape may be defined by a variable parameter which may be either specified by a user or optimized on the basis of a lateral variability parameter calculated for different values of the window parameter.

Abstract: A method for improving prediction of the viability of potential petroleum reservoirs, utilises a rock physics model appropriate for porous media, in which some of the solid material is “floating” or not involved in load support, and predicts permeability on the basis of compressional wave velocity vs. density trends, which may be determined by wireline log. In a further aspect, by introducing the concept of the capture fraction of smaller grains, another constraint is added to the model, which enables an improved estimate of permeability to be determined on the basis of seismic reflectivity measurements alone.

Abstract: A method, apparatus, and article of manufacture provide the ability to determine effects of resuspending gravity currents in a computer system. A slope of a geophysical terrain is determined. A stream function-vorticity description of a fluid motion of a gravity current travelling adjacent to the geophysical terrain is determined. An erosional flux of particles from the geophysical terrain into the gravity current is determined. The particles are incorporated into the gravity current. A description of the gravity current including the incorporated particles is then output (e.g., to a display device).

Abstract: A method for determining impedance coefficients of a seismic trace comprises determining reflection coefficients of the seismic trace, for example using a sparse spike inversion, integrating the reflection coefficients with respect to time to obtain impedance coefficients, and filtering the impedance coefficients by applying a low-cut window filter. The window size and/or shape may be defined by a variable parameter which may be either specified by a user or optimised on the basis of a lateral variability parameter calculated for different values of the window parameter.

Abstract: A method for improving prediction of the viability of potential petroleum reservoirs, utilises a rock physics model appropriate for porous media, in which some of the solid material is “floating” or not involved in load support, and predicts permeability on the basis of compressional wave velocity vs. density trends, which may be determined by wireline log. In a further aspect, by introducing the concept of the capture fraction of smaller grains, another constraint is added to the model, which enables an improved estimate of permeability to be determined on the basis of seismic reflectivity measurements alone.

Abstract: 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.