Node deployment system

Abstract

A seismic node deployment system and method are provided, comprising a deployment device below a surface vessel and having a deployment chute, a connector on the deployment device for a messenger cable, a connector for a remotely operated vehicle (ROV) attached to the deployment chute, a receptacle on the deployment device to receive electrical power from the ROV, a release mechanism on the deployment device to release nodes at desired locations on the seabed, a control unit to allow for communication of commands and to operate the release mechanism; a messenger cable extending from the vessel and connected to a locating rod extending from the deployment device, and releasable deployment latches attached to the seismic nodes and connectable to the messenger cable.

Description

Node Deployment System Atty. Docket No. P-2212 38368-0007Customer No. 174715O F T H E P AT E N T C O O P E RAT I O N T R E AT YTITLE OF THE INVENTIONNode Deployment SystemINVENTORSChristopher Mancini, Tomball, TX (US)Ryan Custer, Tomball, TX (US)Ross Peters, Tomball, TX (US)Eric Hardin, Tomball, TX (US)APPLICANTCaltex Oil Tools, LLC, Tomball, TX (US)BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates in part to devices and methods used in subsea oil and gas exploration activities, and more particularly to such devices and methods which include deployment of seismic nodes on the seabed to record seismic data in support of oil and gas exploration.

[0003] 2. Background and Prior Art

[0004] Oil and Gas exploration relies on seismic surveys to provide high-quality data used to create subsurface imaging. Various seismic methods have been performed to date, with seabed sensors positioned at known locations to detect and record seismic signals.

[0005] On-bottom nodes (OBN) are one such method to capture this seismic survey data. By placing hundreds, often thousands of nodes in pre-determined spacing; either in rows or in a grid pattern on the sea floor using a Remotely Operated Vehicle (ROV), these nodes capture reflected waves in an orderly grid to provide clean, high-fidelity data without gaps in coverage. These nodes- 1 -PD.56102591.3Node Deployment System Atty. Docket No. P-2212 38368-0007Customer No. 174715 typically contain a battery, clock, geophone / seismic sensing technology and other devices. These nodes also improve repeatability, comparing surveys years apart to see how reservoir fluids have moved during field development to help Oil & Gas operators determine where to add wells and how to optimize facilities. Furthermore, on-bottom nodes allow data capture and reporting from the same locations unlike conventional seismic streamers, allowing for higher consistency in data collection.

[0006] In shallow water, these nodes are typically attached to a cable at defined spacing and deployed from the vessel directly to the seabed. This provides the desired seabed spacing and a cost- effective deployment method. For deeper water depths, these nodes are typically deployed to the seabed using a ROV, with the node placed on the seabed using the ROV manipulator and positional placement based on the ROV heading. With seabed surveys typically requiring several thousand nodes to be positioned in a specific array, this method is time-consuming and expensive to implement. Furthermore, data clarity and accuracy are critical, so as well as improving sensor technology, increasing the number of seabed sensing devices and improving the relative location of these sensors provides improved visibility and understanding of the subsurface images created.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with file following drawings, wherein like reference numerals denote like elements.

[0008] Figure 1 illustrates a system overview of the On-Bottom-Node deployment

[0009] Figure 2 illustrates an example of one type of on-bottom node, showing a type of construction and typical dimensions.

[0010] Figure 3 illustrates a deployment latch attachment to be added to the nodes to allow them to be deployed from the surface vessel to the deployment device.

[0011] Figure 4a illustrates a side view of the node deployment device, with the ROV connected via a service line and providing guidance to direct the node placement positioning. The nodes are- 2 -PD.56102591.3Node Deployment System Atty. Docket No. P-2212 38368-0007Customer No. 174715 shown in varying stages of deployment, one shown exiting the deployment tool chute, and another arriving at the top of the tool having travelled down the messenger cable.

[0012] Figure 4b illustrates an isometric view of the same embodiment as Figure 4a.

[0013] Figure 4c illustrates a front view of the same embodiment as Figure 4a.

[0014] Figure 5 illustrates the top end of the deployment device. The nodes are being deployed down the messenger cable from the vessel at surface and are awaiting entry into the device. The ROY service line is shown connected to the deployment device. This is used to disconnect the node from the messenger cable as it enters the deployment device.

[0015] Figure 6 illustrates several nodes stacked up at the top of the deployment device, waiting to be deployed from the deployment device once at the desired location.

[0016] Figure 7 illustrates two views at the upper end of the deployment device. The upper view shows that the node is still connected and retained at the top of the device by the messenger wire. The lower view shows the retaining ring has been opened and the node is free to descend into the deployment chute and exit the device.

[0017] Figure 8 illustrates the lower end of the deployment chute where the node is positioned at the desired location on the seabed.DETAILED DESCRIPTION OF THE INVENTION

[0018] Before the subject invention is further described, it is to be understood that the invention is not limited to the particular embodiments of the invention described below, as variations of the particular embodiments may be made and still fall within the scope of the appended claims. It is also to be understood that the terminology employed is for the purpose of describing particular embodiments and is not intended to be limiting. Instead, the scope of the present invention will be established by the appended claims.

[0019] In this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Unless otherwise specified herein, all- 3 -PD.56102591.3Node Deployment System Atty. Docket No. P-2212 38368-0007Customer No. 174715 materials of construction are preferably steel resistant to the corrosive effects common in oil and gas production environments.

[0020] Turning now to the figures, the present disclosure relates generally to a system and method for deployment of on-bottom nodes on the seabed as part of an offshore seismic survey. Figure 1 illustrates a possible system arrangement for using a ROV 1 to assist with the guidance and power supply for a node deployment device 2. This system coordinates the survey vessel 3 and onboard operations, the acoustic signal from the nodes, and / or the ROV positioning system and a deployment device 2 to efficiently automate the release of the seismic nodes 10 within their defined location and tolerances in a more time efficient method than currently performed.

[0021] The survey vessel 3 will deploy the node deployment device 2 and lower the device until just above the sea floor 5. A buoyancy block 6 may be connected to the deployment device 2 via a buoyancy connector device 14 to provide slack in the messenger cable 7 extending from the vessel 3, which ensures the nodes 10 stack and are deployed properly. The cable 7 is used to deploy the nodes 10 subsea. A latch mechanism 8, as shown in Figure 3, is attached to the nodes 10 and opened so that they can be latched on to the messenger cable 7. The cable 7 then delivers nodes 10 from the surface vessel 3 to the deployment device 2 on the seafloor 5, as shown in Figures 1 and 5. Several nodes 10 can be sent down the cable 7 by gravity, allowing the nodes 10 to stack at the top of the deployment device 2 and be ready for deployment once the ROV 1 is at the correct location, as shown in Figure 6. A release mechanism 11, such as an electric actuator, is attached to the top of the deployment device 2, as shown in Figure 5, and is activated by signals from the ROV 1. A profiled locating rod 12, as shown in Figure 7, has a bottom end that is attached to the deployment device 2 and a top end that is attached to the end of the cable 7. The locating rod 12 ensures the next node 10 to be deployed is positioned correctly against the deployment device 2, directly above the deployment chute 13, and directly below the release mechanism 11.

[0022] A wet-mate electrical receptacle 15 and a subsea control unit 16 are mounted on the deployment device 2 to provide a means for a ROV 1 to supply power and communications to the device, as shown in Figure 5. The deployment device 2 includes an attached guide frame 17, as shown in Figure 5, to allow the ROV 1 to position the deployment device 2 in each prescribed location according to the seismic survey plan. Once the ROV 1 is connected to the deployment device 2 at the attached guide frame 17, the ROV 1 can move the deployment device 2 to each- 4 -PD.56102591.3Node Deployment System Atty. Docket No. P-2212 38368-0007Customer No. 174715 defined location where a node 10 shall be deployed. The ROV 1 positioning system or an acoustic signal from each node 10 may be used to determine the correct drop location. Once on location, the ROV 1 will activate the release mechanism 11, opening the latch mechanism 8 on the node 10 that is to be deployed, releasing the node 10 from the cable 7. The node 10 then falls into the deployment chute 13, which guides the node 10 as shown in Figure 8 and drops each node 10 at its designated location.

[0023] Further enhancements may be made to the proposed system to increase the automation and autonomous nature of these operations. The control system will enable the nodes 10 to be positioned automatically at each of the predefined survey co-ordinates for each node 10. An Autonomous Underwater Vehicle (AUX7) may be used to deploy the nodes 10 cooperating with an automated dispensing device on the vessel 3 to replenish a node 10 after each time a node 10 is located on the seabed 5.

[0024] Another enhancement is to perform node deployment operations independently from the survey vessel 3, using one or multiple AUV’s to deploy the nodes 10, reducing the initial installation costs, and enabling the nodes 10 to remain long term on the seabed 5 without recovery.This will allow oil and gas operators to perform long-term monitoring ot sub-surface hydrocarbon movement as the subsea field matures. AUV’s may be used to capture seismic data from each node 10 after a survey and relay this to a surface data center, and these AUV’s may also re-charge the node batteries.PD.56102591.3

Claims

Node Deployment System Atty. Docket No. P-2212 38368-0007Customer No. 174715CLAIMSThe invention claimed is:

1. A system for deploying seismic nodes comprising:(a) A deployment device comprising: i. A deployment chute; ii. A connector for a messenger cable; iii. A connector for a remotely operated vehicle (ROV) attached to the deployment chute; iv. A receptacle to receive electrical power; v. A release mechanism; vi. A control unit to allow for communication of directions and to operate the release mechanism;(b) A messenger cable connected to foe top of the frame apparatus; and(c) Releasable deployment latches attached to foe seismic nodes.

2. A method for deploying seismic nodes comprising:(a) Attaching releasable deployment latches to the seismic nodes;(b) Attaching the seismic nodes to a cable through the releasable latch;(c) Allowing the seismic nodes to move down foe cable and to a deployment apparatus, which further positions a seismic node for deployment through a rod positioning foe seismic node directly under a release mechanism;(d) Moving and positioning the deployment apparatus to desired locations through a ROV that is connected to foe deployment apparatus and is receiving directional communications;(e) Communicating to foe ROV once foe ROV has moved foe deployment apparatus to foe desired location to activate foe deployment latch release mechanism;(f) Releasing foe seismic node into a deployment chute;(g) Funneling foe seismic node through a deployment chute;(li) Dropping the seismic node out of a deployment chute at the desired location.

3. A system as in claim 1, wherein: a. The deployment apparatus includes a connector for a buoyancy device.- 6 -PD.56102591.3Node Deployment System Atty. Docket No. P-2212 38368-0007 Customer No. 1747154. A method as in claim 2 wherein: a. A buoyancy block is connected to the deployment device, giving slack to the messenger cable to allow for better positioning of the seismic nodes.- 7 -PD.56102591.3

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