Method of obtaining improved geophysical information about earth formations

• US 6,209,640 B1
• Filed: 03/22/2000
• Issued: 04/03/2001
• Est. Priority Date: 02/09/1995
• Status: Expired due to Term

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Reimers, Nils, Leggett, James V. III, Tubel, Paulo S., Harrell, John W.
• Primary Examiner(s): SCHOEPPEL, ROGER J
• Application Number:
  US09/532,466
• Time in Patent Office: 377 Days
• Field of Search: 166/250.01, 166/254.1, 166/65.1, 166/113, 166/64, 367/31, 367/37, 367/911, 181/101, 181/112, 181/122
• US Class Current: 166/254.1
• CPC Class Codes: E21B 33/1275 inflated by down-hole pumping means operated by a down-hole drive
• CPC Class Codes: E21B 37/06 using chemical means for preventing or limiting , e.g. eliminating, the deposition of paraffins or like substances
• CPC Class Codes: E21B 41/0035 Apparatus or methods for multilateral well technology, e.g. for the completion of or workover on wells with one or more lateral branches
• CPC Class Codes: E21B 41/02 in situ inhibition of corrosion in boreholes or wells
• CPC Class Codes: E21B 43/12 Methods or apparatus for controlling the flow of the obtained fluid to or in wells E21B43/25 takes precedence; valve arrangements E21B34/00
• CPC Class Codes: E21B 43/16 Enhanced recovery methods for obtaining hydrocarbons
• CPC Class Codes: E21B 43/20 Displacing by water
• CPC Class Codes: E21B 43/25 Methods for stimulating production by vibrating earth formations E21B43/003
• CPC Class Codes: E21B 47/017 Protecting measuring instruments
• CPC Class Codes: E21B 47/06 Measuring temperature or pressure
• CPC Class Codes: E21B 47/07 Temperature
• CPC Class Codes: E21B 47/107 using acoustic means
• CPC Class Codes: E21B 47/11 using tracers; using radioactivity
• CPC Class Codes: E21B 47/113 using electrical indications; using light radiations
• CPC Class Codes: E21B 47/135 using light waves, e.g. infrared or ultraviolet waves
• CPC Class Codes: E21B 49/00 Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
• CPC Class Codes: E21B 49/006 Measuring wall stresses in the borehole
• CPC Class Codes: E21B 49/008 by injection test; by analysing pressure variations in an injection or production test, e.g. for estimating the skin factor measuring pressure E21B47/06
• CPC Class Codes: E21B 49/08 Obtaining fluid samples or testing fluids, in boreholes or wells
• CPC Class Codes: G01D 5/268 using optical fibres G01D5/28 - G01D5/38 take precedence
• CPC Class Codes: G01N 21/31 : Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry G01N21/72 takes precedence
• CPC Class Codes: G01V 1/24 : Recording seismic data
• CPC Class Codes: G01V 1/40 : specially adapted for well-logging
• CPC Class Codes: G01V 1/42 : using generators in one well and receivers elsewhere or vice versa G01V1/52 takes precedence
• CPC Class Codes: G01V 1/46 : Data acquisition
• CPC Class Codes: G01V 1/52 : Structural details
• CPC Class Codes: G01V 7/08 : using balances
• CPC Class Codes: G01V 7/16 : specially adapted for use on moving platforms, e.g. ship, aircraft
• CPC Class Codes: G01V 8/02 : Prospecting

Abstract

The present invention provides a method for forming wellbores. In one method, one or more wellbores are drilled along preplanned paths based in part upon seismic surveys performed from the surface. An acoustic transmitter conveyed in such wellbores transmits acoustic signals at a one or more frequencies within a range of frequencies at a plurality of spaced locations. A plurality of substantially serially spaced receivers in the wellbores and/or at surface receive signals reflected by the subsurface formations. The sensors may be permanently installed in the boreholes and could be fiber optic devices. The receiver signals are processed by conventional geophysical processing methods to obtain information about the subsurface formations. This information is utilized to update any prior seismographs to obtain higher resolution seismographs. The improved seismographs are then used to determine the profiles of the production wellbores to be drilled. Borehole seismic imaging may then be used to further improve the seismographs and to plan future wellbores. Crosswell tomography may be utilized to further update the seismographs to manage the reservoirs. The permanently installed sensors may also be used to monitor the progress of fracturing in nearby wells and thereby provide the necessary information for controlling fracturing operations.

Claims

1. A method of obtaining geophysical information about subsurface formations, comprising:

(a) forming a survey wellbore along a predetermined wellbore path proximate to a producing formation, a portion of said survey wellbore substantially parallel to a producing reservoir and distant from the surface of the earth;

(b) permanently installing a plurality of spaced apart sensors in the first wellbore;

(c) generating seismic pulses into the earth'"'"'s subsurface formations;

(d) detecting by the plurality of spaced apart sensors seismic waves propagated in earth formations by the generated seismic pulses and generating signals responsive to such detected seismic waves; and

(e) processing the generated signals to obtain geophysical information about the subsurface formations.

2. The method of claim 1 further comprising combining the obtained geophysical information about the subsurface formations with other data to obtain enhanced geophysical information about the earth'"'"'s subsurface formations.

3. The method of claim 1, wherein the enhanced geophysical information is one of (i) a seismograph of the earth'"'"'s subsurface formations, (ii) an acoustic velocity of a subsurface formation, (iii) distance between the survey wellbore and a bed boundary, and (iv) distance between at least two subsurface bed boundaries.

4. The method of claim 3, wherein the seismograph is a 4-D map of the subsurface formations.

5. The method of claim 1, wherein the seismic pulses are generated by a source placed at a location that is one of (i) within the survey wellbore, (ii) at the surface, (iii) an offshore location, and (iv) a secondary wellbore.

6. The method of claim 1 further comprising:

(i) placing a second plurality of spaced apart seismic receivers outside the survey wellbore;

(ii) detecting seismic waves propagated in earth formations by the generated seismic pulses using the second plurality of receivers and generating signals responsive to such detected seismic waves; and

(iii) combining the signals from the first and second pluralities of receivers to obtain the geophysical information.

7. The method of claim 1 further comprising forming at least one wellbore in the hydrocarbon-bearing formation whose wellpath is at least partially determined from the obtained geophysical information.

8. The method of claim 1 further comprising:

(i) subsequently conducting seismic surveys to obtain secondary information about the subsurface formation, and

(ii) combining the obtained geophysical information and the secondary geophysical information to obtain an enhanced map of the subsurface formations.

9. The method of claim 1 further comprising producing a cross-well seismograph from the detected seismic waves.

10. The method of claim 1 wherein the seismic receivers are chosen from the set consisting of:

(i) geophones, (ii) accelerometers, (iii) hydrophones, and, (iv) fiber optic sensors.

11. A method of obtaining geophysical information about subsurface formations, comprising:

(a) forming a first wellbore along a predetermined wellbore path;

(b) generating a first plurality of seismic pulses into the earth'"'"'s subsurface formations at a plurality of spaced apart positions in the first wellbore by means of permanently installed transmitters therein;

(c) detecting by a plurality of seismic receivers seismic waves propagated in earth formations by the first plurality of seismic pulses and generating a first plurality of signals responsive to such detected seismic waves; and

(d) processing the first plurality of signals to obtain geophysical information about the subsurface formations.

12. The method of claim 11 further comprising combining the obtained geophysical information about the subsurface formations with other data to obtain enhanced geophysical information about the earth'"'"'s subsurface formations.

13. The method of claim 12, wherein the enhanced geophysical information is one of (i) a seismograph of the earth'"'"'s subsurface formations, (ii) an acoustic velocity of a subsurface formation, (iii) distance between the survey wellbore and a bed boundary, and (iv) distance between at least two subsurface bed boundaries.

14. The method of claim 13, wherein the seismograph is a 4-D map of the subsurface formations.

15. The method of claim 11, wherein the plurality of seismic receivers are placed at a location that is one of (i) within the survey wellbore, (ii) at the surface, (iii) an offshore location, and (iv) a secondary wellbore.

16. The method of claim 11 further comprising:

(i) generating seismic waves from a second plurality of spaced apart seismic transmitters outside the survey wellbore;

(ii) using the plurality of seismic receivers for detecting seismic waves propagated in earth formations by the second plurality of transmitters and generating a second plurality of signals responsive to such detected seismic waves; and

(iii) combining the first and second plurality signals obtain the geophysical information.

17. The method of claim 11 further comprising forming at least one wellbore in the hydrocarbon-bearing formation whose wellpath is at least partially determined from the obtained geophysical information.

18. The method of claim 11 further comprising:

(i) subsequently conducting seismic surveys to obtain secondary information about the subsurface formation, and

(ii) combining the obtained geophysical information and the secondary geophysical information to obtain an enhanced map of the subsurface formations.

19. The method of claim 11 further comprising producing a cross-well seismograph from the detected seismic waves.

20. The method of claim 11, wherein the seismic receivers are chosen from the set consisting of:

(i) geophones, (ii) accelerometers, (iii) hydrophones, and, (iv) fiber optic sensors.

21. A method of obtaining geophysical information about subsurface formations, comprising:

(a) forming a survey wellbore along a predetermined wellpath formed as a sidebore from a production wellbore;

(b) generating seismic pulses into the earth'"'"'s subsurface formations;

(c) using a plurality of permanently installed seismic receivers in said survey wellbore for detecting seismic waves propagated in said subsurface formations by the generated seismic pulses and generating signals responsive to such detected seismic waves; and

(d) processing the generated signals to obtain geophysical information about said subsurface formations.

22. A method of obtaining geophysical information about subsurface formations, comprising:

(a) forming a survey wellbore along a predetermined wellpath formed as a sidebore from a production wellbore;

(b) generating seismic pulses into the earth'"'"'s subsurface formations using a plurality of permanently installed seismic transmitters in said survey wellbore;

(c) using a plurality seismic receivers for detecting seismic waves propagated in said subsurface formations by the generated seismic pulses and generating signals responsive to such detected seismic waves; and

(d) processing the generated signals to obtain geophysical information about said subsurface formations.