SYSTEM AND METHOD FOR ELEVATED SOURCE TO BOREHOLE ELECTROMAGNETIC SURVEY

• US 20100225322A1
• Filed: 01/29/2010
• Published: 09/09/2010
• Est. Priority Date: 01/29/2009
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: DePavia, Luis, Nichols, Edward, Wilt, Michael, Kramer, Garrett, Morrison, H. Frank
• Granted Patent: US 10,024,995 B2
• Time in Patent Office: Days
• US Class Current: 324/339
• CPC Class Codes: G01V 3/15 specially adapted for use during transport, e.g. by a person, vehicle or boat
• CPC Class Codes: G01V 3/16 specially adapted for use from aircraft G01V3/165 - G01V3/175 take precedence
• CPC Class Codes: G01V 3/30 operating with electromagnetic waves

Abstract

Methods and systems are provided to determine a property of an earth formation, comprising a mobile transmitter disposed at a predetermined elevated height above a surface of the earth formation, and one or more receivers moveably disposed in a wellbore penetrating the earth formation. Electromagnetic energy is transmitted from the mobile transmitter into the formation from a plurality of locations; and at the one or more receivers a signal is measured. Using the signal received by the one or more receivers, a property of the formation, such as resistivity, can be determined and mapped.

Claims

1. ) A method to determine a property of an earth formation, comprising:

providing a mobile transmitter disposed at a predetermined elevated height above a surface of the earth formation;

providing one or more receivers moveably disposed in a wellbore penetrating the earth formation;

transmitting electromagnetic energy from the mobile transmitter into the formation from a plurality of locations;

receiving a signal from the formation with the one or more receivers;

using the signal received by the one or more receivers to determine the property of the formation.

2. ) The method of claim 1, further comprising:

providing a plurality of receivers located on or near the earth'"'"'s surface and configured in an array; and

using the signal received by the one or more receivers in the wellbore and the plurality receivers on or near the earth'"'"'s surface to determine the property of the formation.

3. ) The method of claim 1, wherein the property is resistivity.

4. ) The method of claim 1, wherein the mobile transmitter disposed at a predetermined elevated height above a surface of the earth formation is affixed to a moveable surface vehicle.

5. ) The method of claim 4, wherein the moveable surface vehicle comprises a boat, a truck, tractor, or automobile, or railcar.

6. ) The method of claim 1, wherein the transmitter disposed at a predetermined elevated height above a surface of the earth formation is towed by a moveable airborne vehicle.

7. ) The method of claim 1, further comprising moving the mobile transmitter is in a predetermined pattern.

8. ) The method of claim 7, wherein the predetermined pattern is defined by one selected from the group of 1) multi-azimuthal walk-away lines, 2) a spiral, and 3) a plurality of predetermined heights above the surface of the earth formation.

9. ) The method of claim 1, wherein the receivers comprise electrode sensors, electric field sensors, magnetic field sensors, seismic sensors, or a combination of those sensors.

10. ) The method of claim 1, wherein the receivers are sensitive to electromagnetic energy and/or seismic energy.

11. ) The method of claim 1, further comprising:

providing one or more additional receivers disposed at a predetermined elevated height above a surface of the earth formation; and

using the signal received by the one or more receivers in the wellbore, the receivers disposed at a predetermined elevated height, and the receivers on or near the earth'"'"'s surface to determine the property of the formation.

12. ) The method of claim 1, wherein the predetermined height is selected based on one selected from a group including 1) a given depth of investigation and 2) a given volume of investigation about the wellbore.

15. ) The system of claim 12, further comprising:

a plurality of receivers located on or near the earth'"'"'s surface and configured in an array;

wherein the computer means for inverting the signals is further adapted to use the signals received by the plurality receivers on or near the earth'"'"'s surface with the signals received by the plurality of receivers disposed in the wellbore to determine the property of the formation.

16. ) The system of claim 15, further comprising:

a plurality of additional receivers disposed at a predetermined elevated height above a surface of the earth formation; and

wherein the computer means for inverting the signals is further adapted to use the signals received by the one or more receivers in the wellbore, the receivers disposed at a predetermined elevated height, and the receivers on or near the earth'"'"'s surface to determine the property of the formation.

17. ) The system of claim 12, further comprising a clock means for synchronizing the receivers and transmitter.

18. ) The system of claim 12, wherein the predetermined height is selected based on one selected from a group including 1) a given depth of investigation and 2) a given volume of investigation about the wellbore.

19. ) The system of claim 12, wherein the mobile transmitter disposed at a predetermined elevated height above a surface of the earth formation is affixed to a moveable surface vehicle.

20. ) The system of claim 19, wherein the moveable surface vehicle comprises a boat, a truck, tractor, or automobile, or railcar.

21. ) The system of claim 12, wherein the transmitter disposed at a predetermined elevated height above a surface of the earth formation is towed by a moveable airborne vehicle.

22. ) The system of claim 19, wherein the moveable surface vehicle is adapted to move the mobile transmitter in a predetermined pattern, and the predetermined pattern is defined by one selected from the group of 1) multi-azimuthal walk-away lines, 2) a spiral, and 3) a plurality of predetermined heights above the surface of the earth formation.

23. ) The system of claim 21, wherein the moveable airborne vehicle is adapted to move the mobile transmitter in a predetermined pattern, and the predetermined pattern is defined by one selected from the group of 1) multi-azimuthal walk-away lines, 2) a spiral, and 3) a plurality of predetermined heights above the surface of the earth formation.

13. ) The method of claim 13, wherein the predetermined height is in the range of one to five hundred meters.

14. ) A system to determine a property of an earth formation, comprising:

a mobile transmitter disposed at a predetermined elevated height above a surface of the earth formation wherein the mobile transmitter is adapted to transmit electromagnetic energy into the formation;

a plurality of receivers moveably disposed in a wellbore penetrating the earth formation wherein the receivers are each adapted to receive a signal from the formation; and

a computer means for inverting the signals received by the plurality of receivers to determine the property of the formation.

24. ) A system for reservoir evaluation using mobile transmitters with in-borehole measurements, comprising:

an elevated transmitter broadcasting an electromagnetic (EM) signal in either time or frequency domain through the earth from a plurality of locations;

one or more downhole electromagnetic receivers that detect the EM signal broadcasted by the elevated transmitter; and

computer means for formation resistivity imaging from the well outwards into the reservoir based on EM coupling from an array of measurements taken by the electromagnetic receivers of the EM signal.

25. ) A system for reservoir evaluation using mobile transmitters with in-borehole measurements, comprising:

an elevated transmitter towed by a mobile surface vehicle broadcasting an EM signal in either time or frequency domain through the earth;

one or more downhole electromagnetic receivers that detect the EM signal broadcasted by the elevated, towed transmitter; and

computer means for formation resistivity imaging from the well outwards into the reservoir based on EM coupling from an array of measurements taken by the electromagnetic receivers of the EM signal.

26. ) A method for reservoir evaluation using mobile transmitters with in-borehole measurements, comprising:

positioning an elevated transmitter above the Earth'"'"'s surface;

broadcasting an EM signal in either time or frequency domain through the Earth;

providing an array of downhole electromagnetic receivers in a wellbore;

measuring the broadcast EM signal at each of the downhole electromagnetic receivers;

moving the transmitter to a number of locations;

repeating the step of measuring the broadcast EM signal at each of the downhole electromagnetic receivers; and

imaging the formation resistivity of an area about the wellbore EM coupling from plurality of measurements taken by the electromagnetic receivers of the EM signal.