Abstract: The present invention, in certain embodiments, discloses a method for acquiring marine seismic data using a seismic acquisition system where shot points are determined and shot records recorded. A time at which the source vessel will be substantially at a shot point position is predicted and the seismic source is activated at the shot point. The shot is recorded and the next location for recording a shot is determined. If the source vessel has passed the determined next shot point position, the seismic source is activated and a shot is recorded. If the source vessel has not reached the next shot point, a time delay is implemented until the shot point is reached. The method allows for efficient acquisition of seismic data under varying field conditions by resembling a distance based shot point determination method unless a time based acquisition method becomes more appropriate due to field conditions or other operational considerations.

Abstract: A method of compensating for seismic receiver motion in a marine seismic survey wherein at least one receiver is towed behind a moving seismic vessel comprises producing an acoustic energy wave at a seismic source, and recording the reflection arrival time t2 of the acoustic energy wave at the one receiver. The offset x between the source and the one receiver is determined. The normal moveout velocity V for the acoustic energy, and the velocity VB of the seismic vessel are also estimated. A corrected reflection arrival time t1 , of the acoustic energy wave is then determined by applying a time correction to the recorded reflection arrival time t2. The time correction is a function of the offset x, the normal moveout velocity V, and the velocity VB of the seismic vessel. The method is applicable to a plurality of receivers, whether the receivers are arranged in a single sensor acquisition system or hardwired to form receiver groups.

Abstract: The present invention, in certain embodiments, discloses a method for acquiring marine seismic data using a seismic acquisition system where shot points are determined and shot records recorded. A time at which the source vessel will be substantially at a shot point position is predicted and the seismic source is activated at the shot point. The shot is recorded and the next location for recording a shot is determined. If the source vessel has passed the determined next shot point position, the seismic source is activated and a shot is recorded. If the source vessel has not reached the next shot point, a time delay is implemented until the shot point is reached. The method allows for efficient acquisition of seismic data under varying field conditions by resembling a distance based shot point determination method unless a time based acquisition method becomes more appropriate due to field conditions or other operational considerations.

Abstract: A method of compensating for seismic receiver motion in a marine seismic survey wherein at least one receiver is towed behind a moving seismic vessel comprises producing an acoustic energy wave at a seismic source, and recording the reflection arrival time t2 of the acoustic energy wave at the one receiver. The offset x between the source and the one receiver is determined. The normal moveout velocity V for the acoustic energy, and the velocity VB of the seismic vessel, are also estimated. A corrected reflection arrival time t1 of the acoustic energy wave is then determined by applying a time correction to the recorded reflection arrival time t2. The time correction is a function of the offset x, the normal moveout velocity V, and the velocity VB of the seismic vessel. The method is applicable to a plurality of receivers, whether the receivers are arranged in a single sensor acquisition system or hardwired to form receiver groups.

Abstract: A separator device (3) provided with a cyclone chamber (11, 79) for separating solid and/or liquid particles from a gas flow. The cyclone chamber (11, 79) has an upper wall (49) in which an outlet opening (15) is present, and a substantially rotationally symmetrical side wall (47, 81) in which an inlet opening (13) is present adjacent the upper wall (49). A discharge opening (17, 85) for the separated solid and/or liquid particles is present at a side (55, 83) of the cyclone chamber (11, 79) remote from the upper wall (49). According to the invention, a rotatable annular centrifugal unit (61, 87) is arranged in the cyclone chamber (11, 79) around the outlet opening (15) near the upper wall (49), by means of which unit a short-circuit flow running directly from the inlet opening (13) to the outlet opening (15) in the cyclone chamber (11, 79) is prevented. The efficiency of the separator device (3) is considerably improved thereby.