Patent application number | Description | Published |
20080281667 | Method and Apparatus to Automatically Recover Well Geometry from Low Frequency Electromagnetic Signal Measurements - A technique that is usable with a well includes providing a model so predict measurements that are received by receivers due to transmission by sources baaed on estimated positions of the receivers relative to sources. The estimated positions each have at least two dimensions. At least some of the receivers and the sources are located in the well. On a computer, the estimated positions are automatically refined based on a comparison of the predicted measurements and actual measurements that are obtained by the receivers. | 11-13-2008 |
20090005992 | Method and System for Removing Effects of Conductive Casings and Wellbore and Surface Heterogeneity in Electromagnetic Imaging Surveys - Characterizing a reservoir with electromagnetic imaging surveys includes normalizing measured voltage data by transmitter moment, sorting the normalized voltage data into common receiver profiles, densely resampling transmitter locations using common positions for the receiver profiles, coarsely resampling the data at discreet transmitter locations, defining a starting model for inversion, weighting the data by a factor, converting the normalized voltage data to ratios, calculating a conductivity image using a ratio inversion method, and verifying that an inversion has converged and the image is geologically reasonable. The image can then be displayed. The invention can be used for cross-well, surface-to-borehole, and borehole-to-surface measurements by which the effects of steel casing are reduced. | 01-01-2009 |
20090005993 | Characterizing an Earth Subterranean Structure by Iteratively Performing Inversion Based on a Function - To characterize an earth subterranean structure using a measurement assembly including electromagnetic (EM) receivers and one or more EM sources, measured voltage data collected by EM receivers in response to transmission by one or more EM sources is received. Based on a model, predicted EM data is computed. Inversion is iteratively performed according to a function that computes a difference between the measured voltage data and a product of a term containing the predicted EM data and a term containing distortion data that accounts at least for distortion effect by an environment of the measurement assembly. The inversion is iteratively performed to solve for parameters of the model and the distortion data. | 01-01-2009 |
20090150124 | MODEL BASED WORKFLOW FOR INTERPRETING DEEP-READING ELECTROMAGNETIC DATA - One embodiment of the invention involves a method for determining whether an electromagnetic survey will be able to distinguish between different subsurface conditions in an area that includes developing a three-dimensional electromagnetic property model of the area, and simulating an electromagnetic response of a field electromagnetic data acquisition system using the three-dimensional electromagnetic property model to determine if expected differences in an electromagnetic response of a electromagnetic data acquisition system are within detectability limits of the system. Another embodiment involves a model-based method of inverting electromagnetic data associated with a subsurface area that includes developing a three-dimensional electromagnetic property model of the area, and restricting changes that may be made to the model during the electromagnetic data inversion process. Other related embodiments of the inventive method are also described and claimed. | 06-11-2009 |
20090157316 | METHOD AND SYSTEM FOR REMOVING EFFECTS OF CONDUCTIVE CASINGS AND WELLBORE AND SURFACE HETEROGENEITY IN ELECTROMAGNETIC IMAGING SURVEYS - Characterizing a reservoir with electromagnetic imaging surveys includes normalizing measured voltage data by transmitter moment, sorting the normalized voltage data into common receiver profiles, densely resampling transmitter locations using common positions for the receiver profiles, coarsely resampling the data at discreet transmitter locations, defining a starting model for inversion, weighting the data by a factor, converting the normalized voltage data to ratios, calculating a conductivity image using a ratio inversion method, and verifying that an inversion has converged and the image is geologically reasonable. The image can then be displayed. The invention can be used for cross-well, surface-to-borehole, borehole-to-surface, and single-well (borehole-to-borehole) measurements by which the effects of steel casing are reduced. | 06-18-2009 |
20090157320 | CHARACTERIZING AN EARTH SUBTERRANEAN STRUCTURE BY ITERATIVELY PERFORMING INVERSION BASED ON A FUNCTION - To characterize an earth subterranean structure using a measurement assembly including electromagnetic (EM) receivers and one or more EM sources, measured voltage data collected by EM receivers in response to transmission by one or more EM sources is received. Based on a model, predicted EM data is computed. Inversion is iteratively performed according to a function that computes a difference between the measured voltage data and a product of a term containing the predicted EM data and a term containing distortion data that accounts at least for distortion effect by an environment of the measurement assembly. The inversion is iteratively performed to solve for parameters of the model and the distortion data. | 06-18-2009 |
20100305863 | Characterizing an Earth Subterranean Structure by Iteratively Performing Inversion Based on a Function - To characterize an earth subterranean structure using a measurement assembly including electromagnetic (EM) receivers and one or more EM sources, measured voltage data collected by EM receivers in response to transmission by one or more EM sources is received. Based on a model, predicted EM data is computed. Inversion is iteratively performed according to a function that computes a difference between the measured voltage data and a product of a term containing the predicted EM data and a term containing distortion data that accounts at least for distortion effect by an environment of the measurement assembly. The inversion is iteratively performed to solve for parameters of the model and the distortion data. | 12-02-2010 |
20120191353 | MODEL BASED WORKFLOW FOR INTERPRETING DEEP-READING ELECTROMAGNETIC DATA - One embodiment of the invention involves a model-based method of inverting electromagnetic data associated with a subsurface area that includes developing a three-dimensional electromagnetic property model of the area, and restricting changes that may be made to the model during the electromagnetic data inversion process. Other related embodiments of the inventive method are also described and claimed. | 07-26-2012 |
20140200808 | Phase-Based Electromagnetic Surveys For Geological Formations - An electromagnetic (EM) data acquisition method for a geological formation may include operating EM measurement devices to determine phase and amplitude data from the geological formation. The EM measurement devices may include at least one first EM measurement device within a borehole in the geological formation, and at least one second EM measurement device at a surface of the geological formation. The method may further include processing the phase data independent from the amplitude data to generate a geological constituent map of the geological formation, and identifying different geological constituents in the geological constituent map based upon the measured amplitude data. | 07-17-2014 |
20140239957 | Using Low Frequency For Detecting Formation Structures Filled With Magnetic Fluid - A method for mapping a subterranean formation having an electrically conductive wellbore casing therein may include using a low frequency electromagnetic (EM) transmitter and EM receiver operating at a low frequency of less than or equal to 10 Hertz to perform a first EM survey of the subterranean formation, and with either the low frequency EM transmitter or EM receiver within the electrically conductive well-bore casing. The method may further include injecting a magnetic fluid into the subterranean formation, and using the low frequency EM transmitter and EM receiver to perform a second EM survey of the subterranean formation after injecting the magnetic fluid. | 08-28-2014 |
20140350857 | Method Of Mapping A Subterranean Formation Based Upon Wellbore Position And Seismic Data And Related System - A method of mapping a subterranean formation having at least one wellbore therein may include operating an electromagnetic (EM) signal source and an EM receiver to generate wellbore position data. The method may also include operating a seismic signal source and a seismic receiver to generate seismic data, and generating subterranean formation data based upon the wellbore position data and the seismic data. | 11-27-2014 |