Apparatus and methods for controlling position of marine seismic sources

Abstract

Apparatus and methods are described for remotely controlling position of marine seismic equipment. One apparatus comprises a source connected to a tow member; and an adjustment mechanism connected to the source and the tow member, the adjustment mechanism adapted to actively manipulate an angle of attack of the source. It is emphasized that this abstract is provided to comply with the rules requiring an abstract, which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

1 . An apparatus comprising: 
 a seismic source array connected to a source tow member; and    an adjustment mechanism connected to the source array and the source tow member, the adjustment mechanism adapted to actively manipulate an angle of attack of the source array.    
   
   
       2 . The apparatus of  claim 1  wherein the adjustment mechanism is connected to the source array at one or more tow points located on the source array.  
   
   
       3 . (canceled)  
   
   
       4 . The apparatus of  claim 1 , wherein the source array comprises a float and one or more source members attached to the float.  
   
   
       5 . The apparatus of  claim 4 , wherein the adjustment mechanism comprises a deflecting member able to create lift by changing its angle of attack, wherein the angle of attack of the deflecting member may be the same or different than the angle of attack of the source array.  
   
   
       6 . The apparatus of  claim 5 , wherein the adjustment mechanism further comprises a rigid moment-transfer member having first and second portions, the first portion connected to the source tow member, the second portion connected to a tow point on the deflecting member through a swivel joint.  
   
   
       7 . The apparatus of  claim 6 , wherein the adjustment mechanism further comprises an actuator mounted on the deflecting member near the tow point and adapted to actuate the rigid moment-transfer member.  
   
   
       8 . The apparatus of  claim 1 , further comprising a local controller mounted on the source array, the local controller adapted to receive a signal from a remote controller comprising a desired angle of attack, inform the adjustment mechanism of the desired angle of attack, and signal an actuator to move the adjustment mechanism accordingly.  
   
   
       9 . The apparatus of  claim 8 , wherein the adjustment mechanism further comprises a sensor able to measure the angle of attack.  
   
   
       10 . The apparatus of  claim 6  wherein the deflecting member is selected from a low aspect ratio member and a high aspect ratio member.  
   
   
       11 . (canceled)  
   
   
       12 . The apparatus of  claim 10  wherein the deflecting member is positioned at a position selected from (1) suspended between the float and one or more of the source members and (2) rigidly attached to the float.  
   
   
       13 - 16 . (canceled)  
   
   
       17 . The apparatus of  claim 1  wherein the adjustment mechanism includes a towing harness.  
   
   
       18 . The apparatus of  claim 6  wherein the rigid moment-transfer member is selected from solid members, telescope members, I-beam members and hollow members.  
   
   
       19 . The apparatus of  claim 18  wherein the solid member is selected from cylindrical members and parallelepiped members.  
   
   
       20 - 27 . (canceled)  
   
   
       28 . The apparatus of  claim 1  further comprising: 
 the adjustment mechanism comprising a deflecting member, a bridle system, and an actuator mounted on the deflecting member and operatively connected with the bridle system.    
   
   
       29 . The apparatus of  claim 28  wherein the actuator is positioned on the deflecting member approximately at a mid-section of the deflecting member.  
   
   
       30 . The apparatus of  claim 28  further comprising a local controller mounted on the apparatus, the local controller adapted to receive a signal from a remote controller and send a signal to a motor and the actuator.  
   
   
       31 . The apparatus of  claim 28  wherein the bridle system is remotely adjustable.  
   
   
       32 . The apparatus of  claim 28  wherein the bridle system comprises a front bridle leg attached to a front end of the deflecting member, and an aft bridle leg operatively coupled to the actuator.  
   
   
       33 . The apparatus of  claim 28  wherein the bridle system comprises a frame that is connected to a front end of the deflecting member via a swivel joint, the deflecting member adapted to pivot about the swivel joint, the frame also attached to an aft bridle leg operatively coupled to the actuator.  
   
   
       34 - 36 . (canceled)  
   
   
       37 . The apparatus of  claim 28  wherein the actuator is selected from linear and rotatable actuators.  
   
   
       38 - 39 . (canceled)  
   
   
       40 . The apparatus of  claim 1  further comprising: 
 the adjustment mechanism comprising a deflecting member, a frame, and an actuator mounted on the deflecting member and operatively connected with the frame.    
   
   
       41 . The apparatus of  claim 40  wherein the actuator comprises two linear actuators.  
   
   
       42 . The apparatus of  claim 41  wherein the two linear actuators are remotely controllable.  
   
   
       43 . The apparatus of  claim 42  wherein the adjustment mechanism is devoid of a bridle system.  
   
   
       44 . A system comprising: 
 a tow vessel; and    the source tow member of the apparatus of  claim 1  connected to the tow vessel.    
   
   
       45 . The system of  claim 44  wherein the adjustment mechanism has or has not a direct mechanical connection with the tow vessel.  
   
   
       46 . The system of  claim 45  wherein the direct mechanical connection comprises a passive, strength-taking tow member and an umbilical.  
   
   
       47 . The system of  claim 44  wherein the adjustment mechanism comprises a deflector, the deflector comprising a principal wing-shaped body shaped to produce in use a lateral force which urges the source laterally with respect to the direction of movement of the tow vessel, a boom extending rearward from the principal wing-shaped body, and an auxiliary wing-shaped body, smaller than the principal wing-shaped body, secured to an end of the boom remote from the principal wing-shaped body and shaped so as to produce in use a lateral force in a general direction opposite to that produced by the principal wing-shaped body, and comprising a remotely operable means for adjusting an angle between the boom and the auxiliary wing-shaped body to vary the lateral force produced by the principal wing-shaped body.  
   
   
       48 . The system of  claim 44  wherein the adjustment mechanism comprises a deflector, the deflector comprising a principal wing-shaped body shaped to produce in use a lateral force which urges the source laterally with respect to the direction of movement of the tow vessel, a boom extending rearward from the principal wing-shaped body, and an auxiliary wing-shaped body, smaller than the principal wing-shaped body, secured to an end of the boom remote from the principal wing-shaped body and shaped so as to produce in use a lateral force in a general direction opposite to that produced by the principal wing-shaped body, and comprising a remotely operable means for adjusting an angle between the boom and the principal wing-shaped body to vary the lateral force produced by the principal wing-shaped body.  
   
   
       49 . The system of  claim 44  wherein the adjustment mechanism comprises a deflector, the deflector comprising a plurality of passive hydrofoils suspended between a pair of plates, and at least one active hydrofoil mounted aft of the passive hydrofoils.  
   
   
       50 - 63 . (canceled)  
   
   
       64 . A seismic deflector comprising a plurality of passive hydrofoils suspended between a pair of plates, and at least one active hydrofoil mounted aft of the passive hydrofoils.  
   
   
       65 . The deflector of  claim 64  wherein the active hydrofoil is adapted to be moved and change an angle of attack of the deflector.  
   
   
       66 . The deflector of  claim 65  wherein the active hydrofoil is adapted to be moved using an actuator.  
   
   
       67 . The deflector of  claim 66  wherein the actuator is adapted to be actuated using a local controller and through remote communication between the local controller and a tow vessel.  
   
   
       68 . A method comprising actively controlling an angle of attack of a marine seismic source using the apparatus of  claim 1 .  
   
   
       69 - 98 . (canceled)