OFFSHORE SEISMIC MONITORING SYSTEM AND METHOD

1 . A system for monitoring a reservoir underwater, the system comprising:

plural nodes, each having a seismic sensor for detecting seismic waves;

a remote operated vehicle (ROV) configured to deploy or retrieve the plural nodes to seabed; and

an autonomous underwater vehicle (AUV) configured to monitor and exchange data with the plural nodes,

wherein at least one node of the plural nodes has a head that houses the seismic sensor and the head is configured to burrow in the seabed, up to a predetermined depth, and

the head remains in electrical contact through a connector with a base of the at least one node and the head houses the seismic sensor.

2 . The system of claim 1 , wherein the base of the at least one node further comprises:

a power supply unit;

a seismic data acquisition unit electrically connected to the seismic sensor;

a controller configured to coordinate the burial of the head;

a power supply interface configured to receive power from the ROV or AUV; and

a data and control interface configured to exchange data with the ROV or AUV.

3 . The system of claim 2 , wherein the head further comprises:

a reel for wounding connector; and

an actuator configured to advance a motion of the head into the seabed.

4 . The system of claim 3 , further comprising:

a seismic source configured to generate seismic waves.

5 . The system of claim 1 , further comprising:

a cage configured to store part of the plural nodes, wherein the cage is configured to be deployed from a vessel on the seabed.

6 . The system of claim 5 , wherein the ROV has a robotic arm with which fetches the at least one node from the cage and deploys it on the seabed.

7 . The system of claim 6 , wherein the ROV is programmed to deploy the plural nodes on a grid.

8 . The system of claim 5 , wherein the AUV detects that a node has a depleted power supply unit.

9 . The system of claim 8 , wherein the ROV has a robotic arm with which fetches a charged power supply unit from the cage and replaces the depleted power supply unit of the node with the charged power supply.

10 . The system of claim 1 , wherein the AUV detects a status of the plural nodes.

11 . The system of claim 10 , wherein the status includes at least one of a power status, head status, seismic recording status, and location information of the node.

12 . The system of claim 1 , further comprising:

a support vessel that stores the cage when not deployed and provides control to the ROV.

13 . The system of claim 12 , further comprising:

a source vessel that tows a seismic source that is configured to generate seismic waves.

14 . A method for monitoring a reservoir underwater, the method comprising:

using a remote operated vehicle (ROV) to deploy or retrieve plural nodes to seabed;

deploying an autonomous underwater vehicle (AUV) to monitor and exchange data with the plural nodes;

generating seismic waves with a seismic source;

recording with the plural nodes the seismic waves; and

transferring data indicative of the seismic waves to a processing facility for generating a final image of the reservoir,

wherein at least one node of the plural nodes has a head that houses the seismic sensor and the head is configured to burrow in the seabed, up to a predetermined depth, and

the head remains in electrical contact through a connector with a base of the at least one node during the seismic survey.

15 . The method of claim 14 , further comprising:

sending the AUV to each node to collect the seismic data; and

transferring the seismic data from the AUV to surface.

16 . The method of claim 14 , further comprising:

deploying a cage on the seabed, the cage being configured to store nodes and replacing power units for the nodes.

17 . The method of claim 16 , further comprising:

sending the AUV to each node to collect status information;

informing the ROV when a power unit of a node is found to be depleted; and

replacing the depleted power unit of the node with a charged power unit from the cage.

18 . The method of claim 17 , further comprising:

replacing, using the ROV, a faulty node with a new node from the cage when the AUV detects the faulty node.

19 . A system for monitoring a reservoir underwater, the system comprising:

plural nodes, each having a seismic sensor for detecting seismic waves;

a remote operated vehicle (ROV) configured to deploy or retrieve the plural nodes to seabed;

an autonomous underwater vehicle (AUV) configured to monitor and exchange data with the plural nodes;

a vessel configured to provide support for the AUV and the ROV; and

a cage that is deployed from the vessel to the seabed and configured to store part of the plural nodes,

wherein at least one node of the plural nodes has a head that houses the seismic sensor and the head is configured to burrow in the seabed, up to a predetermined depth.

20 . The system of claim 19 , wherein the base of the at least one node further comprises:

a power supply unit,

a seismic data acquisition unit electrically connected to the seismic sensor,

a controller configured to coordinate the burial of the head,

a power supply interface configured to receive power from the ROV or AUV, and

a data and control interface configured to exchange data with the ROV or AUV; and

wherein the head further comprises:

a reel for wounding connector,

an actuator configured to advance a motion of the head into the seabed, and

a seismic source configured to generate seismic waves.