Patent application number | Description | Published |
20080290874 | APPLICATIONS OF WIDEBAND EM MEASUREMENTS FOR DETERMINING RESERVOIR FORMATION PROPERTIES - A method for determining reservoir formation properties that consists of exciting the reservoir formation with an electromagnetic exciting field, measuring an electromagnetic signal produced by the electromagnetic exciting field in the reservoir formation, extracting from the measured electromagnetic signal a spectral complex resistivity as a function of frequency, fitting the spectral complex resistivity with an induced polarization model and deducing the reservoir formation properties from the fitting with the induced polarization model. | 11-27-2008 |
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 |
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 |
20100185393 | ESTIMATING PETROPHYSICAL PARAMETERS AND INVASION PROFILE USING JOINT INDUCTION AND PRESSURE DATA INVERSION APPROACH - Methods and related systems are described relating to an inversion approach for interpreting the geophysical electromagnetic data. The inversion can be constrained by using a multiphase fluid flow simulator (incorporating pressure data if available) which simulates the fluid flow process and calculates the spatial distribution of the water saturation and the salt concentration, which are in turn transformed into the formation conductivity using a resistivity-saturation formula. In this way, the inverted invasion profile is consistent with the fluid flow physics and moreover accounts for gravity segregation effects. Jointly with the pressure data, the inversion estimates a parametric one-dimensional distribution of permeability and porosity. The fluid flow volume is directly inverted from the fluid-flow-constrained inversion of the electromagnetic data. The approach is not limited by the traditional interpretation of the formation test, which is based on a single-phase model without taking into account invasion or assuming that the fluid, for example mud-filtrate, has been cleaned up from the formation testing zone. The joint inversion of the electromagnetic and pressure data provides for a more reliable interpretation of formation permeability. One advantage of the approaches described herein, is its possible generalization to three-dimensional geometries, for example dipping beds and highly deviated wells. | 07-22-2010 |
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 |
20110231098 | MULTILEVEL WORKFLOW METHOD TO EXTRACT RESISTIVITY ANISOTROPY DATA FROM 3D INDUCTION MEASUREMENTS - A method is provided for determining formation resistivity, anisotropy and dip from wellbore measurements includes moving a well logging instrument through subsurface formations. The instrument includes longitudinal magnetic dipoles and at least one of tilted and transverse magnetic dipoles. Formation layer boundaries and horizontal resistivities of the formation layers are determined from longitudinal magnetic dipole measurements. Vertical resistivities of the formation layers are determined by inversion of anisotropy sensitive measurements. Improved vertical resistivities of the formation layers and dips are determined by inverting symmetrized and anti-symmetrized measurements. Improved vertical resistivities, improved boundaries and improved dips are determined by inversion of the all dipole measurements. Improved horizontal resistivities, further improved layer boundaries and further improved dips are determined by inversion of all dipole measurements. | 09-22-2011 |
20110246140 | DATA SET INVERSION USING SOURCE-RECEIVER COMPRESSION - Source-receiver compression is used to help design surveys and mitigate the computational costs of data set inversion. The source-receiver compression is based on data redundancy and sensitivity. More particularly, a compressed source array is produced for minimum redundancy and maximum sensitivity to reservoir model parameters. The synthesized transmitter array has a reduced number of sources, thereby reducing the number of forward model simulations needed to carry out the inversion. Furthermore, the data collected at the receivers employed in the survey can be compressed. This has the implication of reducing the computational cost of constructing the Jacobian matrix and inverting the corresponding Hessian matrix. | 10-06-2011 |
20120041738 | Method For Upscaling A Reservoir Model Using Deep Reading Measurements - A method of upscaling for reservoir simulation is disclosed, comprising: inverting a set of deep reading measurements constrained by upscaled multi-well data, and, in response to the inverting step, upscaling for reservoir simulation. | 02-16-2012 |
20120119744 | SYSTEM AND METHOD FOR IMAGING PROPERTIES OF SUBTERRANEAN FORMATIONS - A system and method for imaging properties of subterranean formations in a wellbore is provided. The system comprises a formation sensor for collecting currents injected into the subterranean formations, the formation sensor positionable on a downhole tool deployable into the wellbore. The system comprises a controller for controlling the formation sensor and a formation imaging unit. The formation imaging unit comprises a current management unit for collecting data from the currents injected into the subterranean formations, the currents having at least two different frequencies. The formation imaging unit comprises a drilling mud data unit for determining at least one drilling mud parameter, a formation data unit for determining at least one formation parameter from the collected data, and an inversion unit for determining at least one formation property by inverting the at least one formation parameter. | 05-17-2012 |