Abstract: A method, including: obtaining, with a processor, a seismic image of a subsurface region from a computer memory; predicting, with a processor, a dip of the seismic image of the subsurface region; and removing, with a processor, noise or artifacts from the seismic image of the subsurface region by applying a dip guided Laplacian filter, wherein the removing generates another seismic image of the subsurface region that has noise or artifacts removed relative to the seismic image of the subsurface region.

Abstract: Method for reducing the time needed to perform geophysical inversion by using simultaneous encoded sources in the simulation steps of the inversion process. The geophysical survey data are prepared by encoding (3) a group of source gathers (1), using for each gather a different encoding signature selected from a set (2) of non-equivalent encoding signatures. Then, the encoded gathers are summed (4) by summing all traces corresponding to the same receiver from each gather, resulting in a simultaneous encoded gather. (Alternatively, the geophysical data are acquired from simultaneously encoded sources.) The simulation steps needed for inversion are then calculated using a particular assumed velocity (or other physical property) model (5) and simultaneously activated encoded sources using the same encoding scheme used on the measured data. The result is an updated physical properties model (6) that may be further updated (7) by additional iterations.

Abstract: Method for generating an effective, efficient, and stable absorbing boundary condition in finite-difference calculations, such as model-simulation of predicted seismic data. The top surface and optionally the bottom surface of the computational domain or grid are treated with one or more layers of PML (51), preferably 1D PML, assuming an orthorhombic medium in the PML implementation (52). The side surfaces are handled with one or more ABC layers (53). Further advantages may be realized by tapering earth model symmetry axis on the top and bottom of the model toward the vertical (54). The invention provides a beneficial compromise between reducing artifacts in the image or physical property model and computational efficiency and stability.

Abstract: A method for exploring for hydrocarbons, including: simulating a seismic waveform, using a computer, wherein computations are performed on a computational grid representing a subsurface region, said computational grid using perfectly matched layer (PML) boundary conditions that use an energy dissipation operator to minimize non-physical wave reflections at grid boundaries; wherein, in the simulation, the PML boundary conditions are defined to reduce computational instabilities at a boundary by steps including, representing direction of energy propagation by a Poynting vector, and dissipating energy, with the dissipation operator, in a direction of energy propagation instead of in a phase velocity direction; and using the simulated waveform in performing full waveform inversion or reverse time migration of seismic data, and using a physical property model from the inversion or a subsurface image from the migration to explore for hydrocarbons.

Abstract: An additive for a wellbore treatment fluid comprising a sulfonated asphalt compound comprising particles having a D90 particle size of less than about 215 ?m. A wellbore treatment fluid comprising (i) an oleaginous component and (ii) a sulfonated asphalt wherein the sulfonated asphalt comprises particles having a D90 of less than about 215 ?m.

Abstract: A method, including: obtaining an initial model of a subsurface property; simulating synthetic data from the initial model; obtaining recorded borehole seismic data, wherein the recorded borehole seismic data was obtained with a seismic source or receiver located in a well; and inverting, with a computer, the recorded borehole seismic data by full wavefield inversion, wherein the full wavefield inversion includes comparing the synthetic data to the recorded borehole seismic data, and computing a cost function, obtaining a gradient function from the cost function, wherein the gradient function is related to a change in the objective function with an incremental change in model parameters, using the initial model to compute an illumination function or a resolution function for seismic sources and receivers, and obtaining a conditioned gradient function by conditioning the gradient function with the illumination function or the resolution function.

Abstract: Method for correcting seismic simulations, RTM, and FWI for temporal dispersion due to temporal finite difference methods in which time derivatives are approximated to a specified order of approximation. Computer-simulated seismic data (51) are transformed from time domain to frequency domain (52), and then resampled using a mapping relationship that maps, in the frequency domain, to a frequency at which the time derivative exhibits no temporal dispersion (53), or to a frequency at which the time derivative exhibits a specified different order of temporal dispersion. Alternatively, measured seismic data from a field survey (61) may have temporal dispersion of a given order introduced, by a similar technique, to match the order of approximation used to generate simulated data which are to be compared to the measured data.

Abstract: Method for reconstructing subsurface profiles for seismic velocity or other geophysical properties from recorded seismic data. In one embodiment, a starting model of seismic velocity is assumed (10). The computational domain is divided into two (or more) subdomains by horizontal planes based on an analysis of velocity model (30), and the allowed maximum grid size for each subdomain is determined (50). Auxiliary perfectly matched layers (PML's) are attached to each planar interface between subdomains (80), e.g. two PML's on each side of the interface between the coarse and fine subdomains. Simulated seismic data are computed using the SG-DO technique (100-230). The simulated seismic data are compared to the recorded seismic data, then the residual is calculated (240) and used to update the model (320). The method may be iterated until the model is suitably converged (260).

Abstract: An additive for a wellbore treatment fluid comprising a sulfonated asphalt compound comprising particles having a D90 particle size of less than about 215 ?m. A wellbore treatment fluid comprising (i) an oleaginous component and (ii) a sulfonated asphalt wherein the sulfonated asphalt comprises particles having a D90 of less than about 215 ?m.

Abstract: A method for visualization of electrophysiology information can include storing electroanatomic data in memory, the electroanatomic data representing electrical activity on an anatomic region within a patient's body over a time period. An interval within the time period is selected in response to a user selection. A visual representation of physiological information for the user selected interval can be generated by applying at least one analysis method to the electroanatomic data. The visual representation can spatially represented on a graphical representation of the anatomic region within the patient's body.

Abstract: Method and system for more efficient checkpointing strategy in cross correlating (316) a forward (328) and backward (308) propagated wave such as in migrating (326) or inverting seismic data. The checkpointing strategy includes storing in memory forward simulation data at a checkpointed time step, wherein the stored data are sufficient to do a cross correlation at that time step but not to restart the forward simulation. At other checkpoints, a greater amount of data sufficient to restart the simulation may be stored in memory (314). Methods are disclosed for finding an optimal combination, i.e. one that minimizes computation time (1132), of the two types of checkpoints for a given amount of computer memory (1004), and for locating a checkpoint at an optimal time step (306, 1214, 1310). The optimal checkpointing strategy (1002) also may optimize (1408) on use of fast (1402) vs. slow (1404) storage.

Abstract: Systems and methods can be utilized to visualize physiological data relative to a surface region (e.g., an organ) of a patient. A computer-implemented method can include storing electroanatomic data in memory representing electrical activity for a predetermined surface region of the patient and providing an interactive graphical representation of the predetermined surface region of the patient. A user input is received to define location data corresponding to a user-selected location for at least one virtual electrode on the graphical representation of the predetermined surface region of the patient. A visual representation of physiological data for the predetermined surface region of the patient is generated based on the location data and the electroanatomic data.

Abstract: A wellbore treatment fluid comprising one or more high-density weighting materials selected from the group consisting of tungsten-containing materials, bismuth-containing materials, and tin-containing materials.

Abstract: A method for visualization of electrophysiology information can include storing electroanatomic data in memory, the electroanatomic data representing electrical activity on an anatomic region within a patient's body over a time period. An interval within the time period is selected in response to a user selection. A visual representation of physiological information for the user selected interval can be generated by applying at least one analysis method to the electroanatomic data. The visual representation can spatially represented on a graphical representation of the anatomic region within the patient's body.

Abstract: Method for converting seismic data to obtain a subsurface model of, for example, bulk modulus or density. The gradient of an objective function is computed (103) using the seismic data (101) and a background subsurface medium model (102). The source and receiver illuminations are computed in the background model (104). The seismic resolution volume is computed using the velocities of the background model (105). The gradient is converted into the difference subsurface model parameters (106) using the source and receiver illumination, seismic resolution volume, and the background subsurface model. These same factors may be used to compensate seismic data migrated by reverse time migration, which can then be related to a subsurface bulk modulus model. For iterative inversion, the difference subsurface model parameters (106) are used as preconditioned gradients (107).

Abstract: Method for reducing the time needed to perform geophysical inversion by using simultaneous encoded sources in the simulation steps of the inversion process. The geophysical survey data are prepared by encoding (3) a group of source gathers (1), using for each gather a different encoding signature selected from a set (2) of non-equivalent encoding signatures. Then, the encoded gathers are summed (4) by summing all traces corresponding to the same receiver from each gather, resulting in a simultaneous encoded gather. (Alternatively, the geophysical data are acquired from simultaneously encoded sources.) The simulation steps needed for inversion are then calculated using a particular assumed velocity (or other physical property) model (5) and simultaneously activated encoded sources using the same encoding scheme used on the measured data. The result is an updated physical properties model (6) that may be further updated (7) by additional iterations.

Abstract: A method for visualization of electrophysiology information can include storing electroanatomic data (14) in memory, the electroanatomic data representing electrical activity on a surface of an organ over a time period. An interval within the time period is selected in response to a user selection (28). Responsive to the user selection of the interval, a visual representation (26) of physiological information for the user selected interval is generated by applying at least one method to the electroanatomic data (14). The visual representation (26) is spatially represented on a graphical representation of a predetermined region of the surface of the organ.

Abstract: Method for reducing the time needed to perform geophysical inversion by using simultaneous encoded sources in the simulation steps of the inversion process. The geophysical survey data are prepared by encoding (3) a group of source gathers (1), using for each gather a different encoding signature selected from a set (2) of non-equivalent encoding signatures. Then, the encoded gathers are summed (4) by summing all traces corresponding to the same receiver from each gather, resulting in a simultaneous encoded gather. (Alternatively, the geophysical data are acquired from simultaneously encoded sources.) The simulation steps needed for inversion are then calculated using a particular assumed velocity (or other physical property) model (5) and simultaneously activated encoded sources using the same encoding scheme used on the measured data. The result is an updated physical properties model (6) that may be further updated (7) by additional iterations.

Abstract: An improved method for reducing the accuracy requirements on the starting model when performing multi-scale inversion of seismic data (65) by local objective function optimization (64). The different scales of inversion are brought about by incorporating a low-pass filter into the objective function (61), and then decreasing the amount of high-frequency data that is filtered out from one scale to the next. Moreover, the filter is designed to be time varying, wherein the filter's low-pass cutoff frequency decreases with increasing traveltime of the seismic data being filtered (62). The filter may be designed using Pratt's criterion for eliminating local minima, and performing averages (or other statistical measure) of the period and the traveltime error only with respect to source and receiver location but not traveltime (63).