Patent EA-002701-B1 (EA)
Title: Method and system for towing multiple streamers
Inventor: NIELSEN EINAR
IPC: G01V1/38
Filed: 1998-07-21
Abstract: 1. A method for towing seismic equipment behind a marine seismic data equipment handling vessel along a data acquisition path, wherein the equipment comprises, a deflector, attached to a deflector line, which is attached to the equipment handling vessel, the method comprising: attaching a deflector line pulling vessel to the deflector line; spacing the deflector line pulling vessel parallel to the data acquisition path; and pulling the deflector line, with a set of seismic data equipment attached thereto, with both the equipment handling vessel and the deflector line pulling vessel. 2. A method as in claim 1 wherein said attaching a deflector line pulling vessel to the deflector line comprises: attaching a tow line to the deflector line pulling vessel; attaching a detachable connector to the tow line, wherein the detachable connector has a first end and a second end, the first end being detachable from the second end, and wherein the first end is connected to the tow line; attaching the second end of the detachable connector to the deflector line. 3. A method as in claim 2 further comprising attaching a float to the first end of the detachable connector. 4. A method as in claim 2 or 3 further comprising attaching a float to the second end of the detachable connector. 5. A method as in claim 2 further comprising towing a detachable connector behind the deflector line pulling vessel, wherein an acoustic signal transponder activates said detachable connector. 6. A method as in claim 1 wherein said attaching a deflector line pulling vessel to the deflector line comprises: attaching a tow line to the deflector line pulling vessel; attaching a first detachable connector to the tow line, wherein the first detachable connector has a first end and a second end, the first end being detachable from the second end, and wherein the first end is connected to the deflector line; attaching the second end of the first detachable connector to a first end of an intermediate line; attaching a second end of the intermediate line to a first end of a second detachable connector, wherein the second detachable connector also comprises a second end which is detachable from the first end of the second detachable connector; and attaching the second end of the second detachable connector to the tow line. 7. A method as in claim 6 wherein said first detachable connector comprises a release device. 8. A method as in claim 1 wherein said attaching a deflector line pulling vessel to the deflector line comprises attaching the deflector line pulling vessel to the deflector line between the deflector and an outermost attachment of a streamer. 9. A method as in claim 1 further comprising controlling the deflector line pulling vessel from the equipment handling vessel. 10. A system for towing seismic equipment behind a marine seismic data equipment handling vessel along a data acquisition path, the system comprising: a deflector attached to a deflector line; an equipment handling vessel attached to the deflector line; and a deflector line pulling vessel attached to the deflector line, wherein the marine seismic data equipment is attached to the deflector line. 11. A system as in claim 11 further comprising: a tow line attached to the deflector line pulling vessel; a detachable connector attached to the tow line, wherein the detachable connector has a first end and a second end, the first end being detachable from the second end, wherein the first end is connected to the tow line, and the second end of the detachable connector is attached to the deflector line. 12. A system as in claim 11 further comprising a float attached to the first end of the detachable connector. 13. A system as in claim 11 or 12 further comprising a float attached to the second end of the detachable connector. 14. A system as in claim 11 wherein said detachable connector comprises a release device. 15. A system as in claim 13 further comprising an acoustic transponder towed behind the deflector line pulling vessel, wherein said release device is responsive to said acoustic transponder. 16. A system as in claim 10 further comprising: a tow line attached to the deflector line pulling vessel; a first detachable connector attached to the tow line, wherein the detachable connector has a first end and a second end, the first end being detachable from the second end, wherein the first end is connected to the deflector line, the second end of the detachable connector is attached to a first end of an intermediate line; a second end of the intermediate line attached to a first end of a second detachable connector,  wherein the second detachable connector also comprises a second end which is detachable from the first end of the second detachable connector and wherein the second end of the second detachable connector is attached to the tow line. 17. A system as in claim 11 wherein said deflector line pulling vessel is attached to the deflector line between the deflector and an outermost attachment of a streamer. 18. A towing harness for use with a seismic streamer equipment handling vessel and a supplementary vessel, the harness comprising: an equipment handling vessel spur; a deflector spur connected to said equipment handling spur; and a supplementary vessel spur connected to said equipment handling spur and said deflector spur. 19. A harness as in claim 18 wherein: said supplementary vessel spur comprises a detachable connector having a first end and a second end; the first end of the detachable connector is detachable from the second end of the detachable connector, the first end of the detachable connector is connected to a vessel portion of the supplementary vessel spur; and the second end of the detachable connector is connected to a deflector portion of the supplementary vessel spur. 20. A harness as in claim 19 wherein said detachable connector comprises an acoustic release. 21. A harness as in claim 19 wherein said detachable connector comprises a mechanical release. 22. A harness as in claim 19 further comprising a float attached to said first end of the detachable connector. 23. A harness as in claim 19 further comprising a float attached to said second end of the detachable connector. 24. A harness as in claim 19 further comprising a supplementary detachable connector located in the vessel portion of the supplementary vessel spur.