Claims
- 1. A method for generating an image of earth formations penetrated by a wellbore, comprising:
generating an initial model of the earth formations using formation resistivity measured by a direct current signal; calculating a response to the initial model of an instrument used to make the direct current resistivity measurements; comparing the calculated response to the measurements of resistivity; adjusting the model and repeating the calculating and comparing until a difference between the calculated response and measurements reaches a minimum; refining the adjusted model based on resistivity measurements made using an electromagnetic measuring instrument; and constraining the refined model using acoustic measurement parameters.
- 2. The method of claim 1 wherein the electromagnetic resistivity measurements comprise time domain electromagnetic measurements.
- 3. The method of claim 1 wherein the electromagnetic resistivity measurements comprise frequency domain electromagnetic measurements.
- 4. The method of claim 1 wherein the acoustic velocity measurements comprise seismic travel time measurements.
- 5. An instrument for well loggin a subsurface formation penetrated by a wellbore, comprising:
a central unit comprising a communication system for communicating with surface equipment; at least one of a three-component instrument which is adapted to transmit or sense a magnetic field and at least one electric field transmitter, disposed within said central unit; at least two electrode assemblies positioned on said central unit, said electrode assemblies having a plurality of electrode contacts positioned thereon so that said contacts are usable as either a ring electrode or as discrete electrodes; a seismic sensor positioned on said central unit; a least one auxiliary unit spaced apart on said tool from said central unit; at least one of a three-component instrument which is adapted to either transmit or sense a magnetic field and an electric field transmitter disposed within said auxiliary unit; at least two electrode assemblies positioned on said auxiliary unit, said electrode assemblies having a plurality of electrode contacts positioned thereon so that said contacts are usable as either a ring electrode or as discrete electrodes; a seismic sensor positioned on said auxiliary unit; and a control system on said central unit for controlling operation of said tool.
- 6. The tool of claim 5 wherein at least one of said seismic sensors comprises a three component geophone and a hydrophone.
- 7. The tool of claim 5 wherein at least one of said seismic sensors comprises a four component geophone having sensors oriented so as to be substantially equally sensitive to noise in all directions.
- 8. The tool of claim 5 wherein at least one of said seismic sensors comprises a hydrophone and a four component geophone having sensors oriented at substantially 54 degree angles from each other.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of U.S. application Ser. No. 09/938,355 filed on Aug. 23, 2001. This patent application may be related to the following Disclosures:
[0002] 1. Disclosure Document No. 461,019, Integrated Borehole System for Reservoir Detection and Monitoring, by Kurt-Martin Strack, Aug. 24, 1999
[0003] 2. Disclosure Document No. 462,894, Method of Predicting Conductivity Anomalies Ahead of the it Using an Integrated Seismic/Electromagnetic System, by Kurt-Martin Strack, Sep. 27, 1999
[0004] 3. Disclosure Document No. 462,893, Integrated Modeling System for 3D Seismic Data Using Reservoir Data as Constraints, by Kurt-Martin Strack, Sep. 27, 1999
[0005] 4. Disclosure Document No. 481,380, Improving Pore Pressure Prediction Using Log Inversion and Modeling, by Kurt-Martin Strack, Oct. 18, 2000
[0006] 5. Disclosure Document No. 495,407, Surface and Borehole Integrated Electromagnetic Apparatus to Determine Reservoir Fluid Properties, by Kurt-Martin Strack, Jun. 16, 2000
Continuations (1)
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Number |
Date |
Country |
Parent |
09938355 |
Aug 2001 |
US |
Child |
10401216 |
Mar 2003 |
US |