Abstract: The present invention is a method of generating a geologic model which incorporates a local spatial trend in rock property continuity. Initially, a candidate geologic model is generated by assigning a rock-property value to each block of a model grid. Next, local spectra which characterize the desired local spatial trend in rock property continuity are specified. These local spectra are used to frequency scale the rock-property values of the candidate geologic model. The scaled rock-property values are then combined to generate a scaled geologic model that incorporates the local spatial trend in rock property continuity.

Abstract: A process for constructing a three-dimensional geologic model of a subsurface earth volume wherein resolution scales of multiple diverse data types, including seismic data, are accounted for by generating multiple frequency passband models and combining them together to form the complete geologic model. Preferably, a model is generated for each of a low-frequency passband, a mid-frequency passband, and a high-frequency passband. When integrating seismic data into the modeling process, the seismic-frequency passband constitutes the mid-frequency passband model. The process further contemplates updating tentative frequency-passband models through optimization of assigned rock property values in each tentative model according to specified geological criteria. Such optimization is carried out by perturbation of the rock property values in a manner wherein the frequency content of each model is maintained.

Abstract: The present invention is a method of generating a model of a random field which has directionally varying continuity. First, a tentative model for the random field is specified. Second, connected strings of nodes within the model are identified. Third, a spectral simulation on each of the strings of nodes is performed to determine updated values for the random field. Finally, the tentative model is updated with the data values from the spectral simulations.

Abstract: The present invention is a method of generating a model of a random field which has directionally varying continuity. First, a tentative model for the random field is specified. Second, connected strings of nodes within the model are identified. Third, a spectral simulation on each of the strings of nodes is performed to determine updated values for the random field. Finally, the tentative model is updated with the data values from the spectral simulations.

Abstract: The present invention is a method of generating a geologic model which incorporates a local spatial trend in rock property continuity. Initially, a candidate geologic model is generated by assigning a rock-property value to each block of a model grid. Next, local spectra which characterize the desired local spatial trend in rock property continuity are specified. These local spectra are used to frequency scale the rock-property values of the candidate geologic model. The scaled rock-property values are then combined to generate a scaled geologic model that incorporates the local spatial trend in rock property continuity.

Abstract: A process for constructing a three-dimensional geologic model of a subsurface earth volume wherein resolution scales of multiple diverse data types, including seismic data, are accounted for by generating multiple frequency passband models and combining them together to form the complete geologic model. Preferably, a model is generated for each of a low-frequency passband, a mid-frequency passband, and a high-frequency passband. When integrating seismic data into the modeling process, the seismic-frequency passband constitutes the mid-frequency passband model. The process further contemplates updating tentative frequency-passband models through optimization of assigned rock property values in each tentative model according to specified geological criteria. Such optimization is carried out by perturbation of the rock property values in a manner wherein the frequency content of each model is maintained.

Abstract: A method for analyzing seismic intervals and predicting subsurface petrophysical properties through the use of a new set of attributes known as Linear Shape Attributes (LSAs). The Linear Shapes form an orthogonal basis set derived directly from the seismic data traces for the interval in question. Collectively, the LSAs capture substantially all of the useful information contained in the input data set. The input data set may include all or a selected portion of the seismic data traces for the prospect. Petrophysical information obtained from well logs and/or pseudo-well logs may be used to calibrate the LSAs. The calibrated LSAs may then be used for a variety of purposes, such as predicting subsurface petrophysical properties at other locations or determining the location of a new well.

Abstract: A method for restoring to filtered seismic data at least some of the ramdom background noise associated with the data in its form prior to filtering. The method includes the steps of filtering seismic data in a two-dimensional filter; generating a noise signal representing the random background noise associated with the data; filtering the noise signal in an inverse filter corresponding to the two-dimensional filter; and adding the inverse-filtered first signal to the filtered seismic data. In one embodiment, the noise signal is generated by filtering a copy of the data in a least-mean-squares adaptive filter to remove substantially all coherent energy therefrom. In another embodiment, the noise signal is an independently generated white noise signal having beginning and end times matching those of the seismic data. This white noise signal is the bandpass filtered to cause its frequency content to match that of the seismic data.