VIBRATORY SOURCE FOR NON-VERTICAL BOREHOLES AND METHOD

• US 20180038972A1
• Filed: 12/15/2015
• Published: 02/08/2018
• Est. Priority Date: 03/27/2015
• Status: Active Grant

• Current Assignee: Cgg Services Sas (CGG)
• Original Assignee: Cgg Services Sas (CGG)
• Inventors: GRESILLON, Franois-Xavier, FORGUES, Eric
• Granted Patent: US 10,641,913 B2
• Time in Patent Office: Days
• 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: G01V 1/143 using mechanical driving means , e.g. motor driven shaftG01V1/104, G01V1/133 take precedence
• CPC Class Codes: G01V 1/145 by deforming or displacing surfaces , e.g. by mechanically driven vibroseis™
• CPC Class Codes: G01V 1/159 using piezoelectric or magnetostrictive driving means generating mechanical vibrations by using piezoelectric or magnetostrictive effect in general, B06B1/06, B06B1/08
• CPC Class Codes: G01V 1/52 Structural details

Abstract

A reaction mass seismic survey source that is located in an underground casing. The seismic source includes a non-planar base plate; a reaction mass located on the non-planar base plate; and a flextensional element housed in a recess of the reaction mass and configured to vibrate the non-planar base plate when actuated, to generate seismic waves underground.

Claims

1. A reaction mass seismic source that is located in an underground casing, the seismic source comprising:

a non-planar base plate;

a reaction mass located on the non-planar base plate; and

a flextensional element located between the reaction mass and the base plate and configured to vibrate the non-planar base plate when actuated, to generate seismic waves underground.

2. The seismic source of claim 1, further comprising:

a guidance piston located between the flextensional element and the base plate.

3. The seismic source of claim 1, wherein the flextensional element comprises:

a piezoelectric element that changes its size when actuated by a voltage; and

an elastic element located around the piezoelectric element and configured to change its shape when the piezoelectric element is actuated.

4. The seismic source of claim 1, further comprising:

support devices located between the reaction mass and the base plate and configured to support a weight of the reaction mass such that the flextensional element is protected from the weight of the reaction mass.

5. The seismic source of claim 1, wherein a weight of the non-planar base plate is between 200 and 400 kg.

6. The seismic source of claim 1, wherein the flextensional element includes between one and ten flextensional elements.

7. The seismic source of claim 1, further comprising:

a coupling element configured to be in a retracted state when the seismic source travels through the underground casing and to press against a wall of the casing when the seismic source is in a shooting location.

8. The seismic source of claim 1, wherein a center of mass of the source is lower than a geometric center so that the base plate remains below the reaction mass when the source travels through the casing.

9. The seismic source of claim 1, wherein the seismic source travels through a non-vertical casing to a desired position and shoots from a non-vertical position.

10. A reaction mass seismic source that is located in an underground casing, the seismic source comprising:

plural individual source elements connected to each other, a source element comprising;

a non-planar base plate;

a reaction mass located on the non-planar base plate; and

a flextensional element housed in a recess of the reaction mass and configured to vibrate the non-planar base plate when actuated to generate seismic waves.

11. The seismic source of claim 10, wherein the flextensional element comprises:

a piezoelectric element that changes its size when actuated by a voltage; and

an elastic element located around the piezoelectric element and configured to change its shape when the piezoelectric element is actuated.

12. The seismic source of claim 10, wherein the source element further comprises:

support devices located between the reaction mass and the base plate and configured to support a weight of the reaction mass such that the reaction mass does not touch the base plate.

13. The seismic source of claim 10, wherein flextensional element includes between one and ten flextensional elements.

14. The seismic source of claim 10, wherein the source element further comprises:

a coupling element configured to be in a retracted state when the seismic source element travels through the underground casing and to press against a wall of the casing when the seismic source element is in a shooting location.

15. The seismic source of claim 10, wherein a center of mass of each of the seismic source elements is lower than a geometric center so that the base plate is below the reaction mass.

16. The seismic source of claim 10, wherein the seismic source elements travel through a non-vertical casing to desired positions and shoot from non-vertical positions.

17. A method for generating seismic waves in a non-vertical borehole, the method comprising:

positioning a source element in a non-vertical borehole;

extending a coupling element to push a non-planar base plate of the source element against a wall of the borehole;

actuating a flextensional element located inside a reaction mass of the source element; and

generating the seismic waves by vibrating the non-planar base plate with the flextensional element.

18. The method of claim 17, further comprising:

supporting the reaction mass with a support device so that the reaction mass does not touch the non-planar base plate.

19. The method of claim 17, wherein the coupling element is attached to the non-planar base plate and extends through the reaction mass.

20. The method of claim 17, further comprising:

retracting the coupling element within the reaction mass; and

moving the source element to a new position within the non-vertical borehole.