Diverse bubble size generation

• US 8,276,889 B2
• Filed: 03/15/2012
• Issued: 10/02/2012
• Est. Priority Date: 07/06/2006
• Status: Active Grant

• Current Assignee: Exxonmobil Upstream Research Company (Exxon Mobil Corporation)
• Original Assignee: Exxonmobil Upstream Research Company (Exxon Mobil Corporation)
• Inventors: Norris, Michael W., Heiney, Steven E., Ross, Warren S., Johnson, Marvin L.
• Primary Examiner(s): BUSHEY, CHARLES S
• Application Number:
  US13/421,234
• Publication Number:
  US 20120168972A1
• Time in Patent Office: 201 Days
• Field of Search: 261/122.1, 261/123, 261/124, 261/120, 367/15, 367/24, 702/13, 702/14, 702/17
• US Class Current: 261/120
• CPC Class Codes: G01V 1/3808 Seismic data acquisition, e.g. survey design

Abstract

Method and apparatus for producing a bubble curtain with a diversity of bubble diameters for purposes such as modifying the characteristics of a seismic source used in marine seismic surveys. Bubble generating elements are used that combine porous wall material with discrete holes (91) to create a curtain of diverse-sized bubbles (92).

Claims

1. A bubble generator for making a bubble curtain to suppress surface-related multiple reflections in marine seismic surveys, comprising:

(a) a frame;

(b) a plurality of bubble diffuser elements attached to the frame, said diffuser elements enclosing hollow chambers with walls designed to leak pressure by virtue of a combination of porous wall material and one or more discrete holes; and

(c) a tube connected to the chamber in every diffuser element, said tube being adapted to be connected to a pressurized source of gaseous fluid;

wherein the bubble generator is adapted to be towed through water.

2. The bubble generator of claim 1, wherein all wall material enclosing the hollow chambers is porous wall material that contains one or more discrete holes.

3. The bubble generator of claim 1, wherein the discrete holes are perforations in the wall material.

4. The bubble generator of claim 1, wherein the discrete holes are made using a punch, drill or laser beam.

5. The bubble generator of claim 1, wherein the discrete holes are greater than about 300 microns in effective diameter.

6. The bubble generator of claim 5, wherein the discrete holes are between about 1,000 and 2,000 microns in effective diameter.

7. The bubble generator of claim 1, wherein pores in the porous wall material have effective diameter less than about 400 microns.

8. The bubble generator of claim 1, wherein pores in the porous wall material have effective diameter between about 50 microns and about 200 microns.

9. The bubble generator of claim 1, further comprising a nozzle connected to a discrete hole for at least one of the discrete holes.

10. The bubble generator of claim 1, further comprising one or more surface floats attached by connecting lines to the bubble generator.