Method and System for Adjusting Vessel Turn Time with Tension Feedback
AssigneePGS Geophysical AS
InventorsJan Erik Stokkeland, Mattias Dan Christian Oscarsson, Rune Tønnessen
Life of this patent
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Abstract
Disclosed are methods and systems for using tension feedback from steerable deflectors to adjust vessel turn time. In one example, a maximum tension for a second steerable first towed on a first side of the survey vessel may be determined. A radius of a turn of the vessel at a preselected speed may further be selected such that the tension on the first steerable deflector is less than the maximum tension. The vessel may be turned while moving at the preselected speed, wherein the turning of the vessel has the selected radius. Tension may be measured on the first steerable deflector during the step of turning the vessel.
Claims22
A method for adjusting vessel turn time with tension feedback in a geophysical survey, comprising:
- determining a maximum tension for a first steerable deflector towed from the survey vessel;
- selecting a radius of a turn of the vessel at a preselected speed such that the tension on the first steerable deflector is less than the maximum tension;
- turning the vessel while moving at the preselected speed, wherein the turning of the vessel has the selected radius;
- and
- measuring tension on the first steerable deflector during the step of turning the vessel.
A method for reducing vessel turn time with tension feedback in a geophysical survey, comprising:
- towing a plurality of sensor streamers from a survey vessel in a body of water;
- adjusting an angle of attack of one or more steerable deflectors as the survey vessel heads into a turn such that a spread of equipment towed by the survey vessel is shifted into the turn;
- turning the survey vessel;
- and
- measuring tension on the one or more steerable deflectors during the step of turning the vessel.
A marine geophysical survey system comprising:
- a survey vessel;
- a plurality of laterally spaced apart sensor streamers towed by the survey vessel;
- steerable deflectors towed by the survey vessel for maintaining lateral separation of the sensor streamers;
- deflector lead-in lines, wherein each of the deflector lead-in lines is coupled at one end to the survey vessel and at the other end to a corresponding one of the steerable deflectors;
- a spreader line extending at least partially between the steerable deflectors, wherein the spreader lines is coupled to a forward end of the sensor streamers;
- tension measurement systems, wherein each of the tension measurement systems is configure to measure tension on a corresponding one of the steerable deflectors;
- and
- a control system configured to (i) determine a turn radius for the survey vessel such that the tension on each of the deflectors does not exceed a predetermined minimum tension and/or is less than a predetermined maximum tension, (ii) receive the measured tension from the tension measurement systems during a turn of the survey vessel, and (iii) at least one of adjusting angle of attack for the steerable deflectors, adjusting vessel speed, or adjusting the turn radius.
Dependencies are inferred from the claim text.