Abstract: A method of performing a seismic survey of a hydrocarbon reservoir in the earth formations beneath a body of water includes deploying a seismic cable from a drum carried by a remotely operated vehicle on the seabed. The cable is deployed into a lined trench, which is formed either concurrently with cable deployment or during a previous survey, to ensure good repeatability of successive surveys of the reservoir, in order to enable changes in characteristics of the reservoir, eg due to depletion, to be monitored.

Abstract: A method of performing a seismic survey of earth formations beneath a body of water is disclosed. The method includes: (a) deploying a seismic cable having a plurality of seismic sensors distributed therealong in close proxmity to elongate locating means provided at the bottom of the body of water; (b) operating an acoustic source in the body of water to produce seismic signals which enter the formations; (c) detecting seismic signals which return from the formations with said sensors; and (d) removing the seismic cable from the bottom of the body of water.

Abstract: A housing for a seismic sensing element (3) for use on the earth's surface comprises connecting means (5) for connecting the housing (3) to a support cable (2) so as to allow relative movement between the sensor housing (3) and the cable (2). This de-couples the sensor housing from the support cable, and improves the fidelity of the sensor.

Abstract: A method of performing a seismic of a hydrocarbon reservoir in the earth formations beneath a body of water includes deploying a seismic cable from a drum carried by a remotely operated vehicle on the seabed. The cable is deployed into a lined trench, which is formed either concurrently with cable deployment or during a previous survey, to ensure good repeatability of successive surveys of the reservoir, in order to enable changes in characteristics of the reservoir, eg due to depletion, to be monitored.