Methods and apparatus for emergency rig monitoring

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METHODS AND APPARATUS FOR
EMERGENCY RIG MONITORING

FIELD OF THE INVENTION

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Embodiments of the invention generally relate to methods and apparatus for monitoring offshore structures and vessels. More particularly, the invention relates to methods and apparatus for monitoring offshore hydrocarbon rigs and communicating rig data to a location remote from the rig. 1°

BACKGROUND OF THE INVENTION

Exploration for and production of hydrocarbon based energy deposits has often required that people and equip- 15 ment operate in challenging and potentially hazardous environments around the world. As hydrocarbon deposits become more difficult to find, more exploration and production activities are occurring in bodies of water including oceans and seas. Offshore hydrocarbon exploration and 20 production requires that expensive rigs or vessels be semipermanently located in bodies of water. Many bodies of water are subject to dramatic and sudden changes in weather. More notorious examples of such changes include storms such as tropical storms, typhoons, and hurricanes. 25

Offshore rigs are usually supported structurally from the sea floor (e.g. jack-up rigs and island rigs) or are supported by buoyant structures (e.g. semi-submersibles, spars, ships). Some hybrid designs exist. Most rigs are moored to the sea 3Q floor by anchors and mooring lines in order to resist lateral rig movement. Such rigs are usually manned either around the clock or intermittently in order to monitor and maintain rig systems and operations.

When a storm approaches an offshore rig the safety of the 35 rig crew becomes a primary issue. The condition and location of the rig are also at issue. As a storm approaches the rig crew is evacuated either by boat or helicopter and the rig is left unmanned or partially unmanned. Events that occur as the storm draws near to and impacts the rig go largely 4Q unmonitored. If standard rig communications go down before an evacuation can occur, the situation for the rig crew becomes critical. If the rig is evacuated before a storm arrives then the condition and location of the rig become unknown until some time after the storm has passed. 45

If the storm has damaged critical rig systems including mooring lines, such damage can not be detected until after the storm has passed. In many cases a rig that has been hit or almost hit by a storm can not even be readily located because the mooring lines have been broken and the rig has 50 drifted. Rigs have been blown off location by hundreds of miles in some instances. Such drifting rigs create a hazard separate from that of the storm in that the rig may actually impact another vessel or structure. An ability to locate a drifting rig and advance warning of the status and course of 55 such a rig is needed. So that design insight may be gained for the future, an ability to analyze events leading up to the loss of a rig at sea is also needed.

Methods for tracking things such as automobiles, boats and airplanes have been devised. Devices such as Lo-Jack 60 (registered) have been marketed for tracking stolen automobiles. When activated, that device sends a radio signal that can be received by a tracking device. Such a device does not provide exact automobile location; rather it provides location information relative to the tracking receiver. The Lo- 65 Jack device is described in U.S. Pat. Nos. 4,908,629, 4,818, 998, and 4,177,466.

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A system and method for monitoring a boat are subjects of U.S. Pat. No. 6,469,641. That patent discloses tracking a stolen boat and monitoring certain security and operational parameters related to the boat such as unauthorized entry, bilge pump function, battery charge, and boat location. Such a system for monitoring of a boat does not address parameters relevant to a rig or its environment.

While there are many different types of tracking and monitoring systems including some for marine vessels, none address issues and parameters that are of specific interest regarding an offshore hydrocarbon rig.

Accordingly, there is a need for an invention that facilitates the monitoring of parameters related to an offshore rig and the communication of information related to the offshore rig to a remote location where concerned persons are able to access such information. Such an invention should preferably operate in inclement weather and through periods of rig power interruption.

SUMMARY OF THE INVENTION

The invention generally relates to methods and apparatus for monitoring an offshore rig. The rig monitoring systems and methods of use can relay information regarding the rig such as location, attitude (e.g. tilt, oscillation), and local water and weather conditions. The rig monitoring systems and methods can also facilitate emergency communication for rig personnel. Access to the information can be remotely initiated and the systems can be configured to automatically respond to such initiation. The rig monitoring systems are equipped with a self-sustainable power supply for operation under conditions where external power sources are unavailable. Such rig monitoring systems and methods are particularly useful on rigs that are located in waters subject to rapid and severe changes in local weather such as storms.

A method for preparing a rig for adverse climatic conditions is included herein and comprises:

receiving notification of an approaching adverse climatic condition;

ceasing rig activities related to at least one of hydrocarbon

exploration and production; securing equipment on the rig; evacuating the rig;

monitoring the adverse climatic condition; monitoring at least one rig parameter; and communicating data related to the rig parameter to a remote location.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of the invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

FIG. 1 shows a schematic representation of a rig monitoring system (1).

FIG. 2 shows a rig icon (7) plotted on a geographic map (8).

FIG. 3 shows a zoom in of map (8) focusing on the rig icon (7) and including a storm (20) and storm track (21).

FIG. 4 shows an embedded data set (10) associated with the user interactive rig icon (7) plotted on the map (8).

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FIG. 5 shows an example data set in tabular form. FIG. 6 shows a method for at least temporarily ceasing rig operations.

DETAILED DESCRIPTION OF THE 5
PREFERRED EMBODIMENT

One embodiment hereof comprises a method for remotely monitoring a parameter on at least one offshore hydrocarbon rig. Hydrocarbon rigs contemplated herein include drilling io rigs, production platforms, processing terminals, floating storage vessels, pipeline switching or access terminals and other facilities positioned offshore for use in the hydrocarbon production and delivery process. Such hydrocarbon rigs mat be jacked up, semi-submersible, or floating and may be 15 anchored to the sea floor with mooring lines or dynamically positioned or any suitable combination thereof.

Referring to FIG. 1 the embodiment includes providing a rig monitoring system (1) comprising at least one data acquisition system (2) having at least one parameter sensor 20 (3) and at least one power supply (4) configured to operate independently of an external power source. Further provided is at least one remote data access member (5). The parameter sensor (3) is positioned so that it monitors at least one parameter related to the offshore hydrocarbon rig. Data is 25 acquired from the parameter sensor (3) and then communicated to a remote location having a remote access member (5).

So that the data acquisition system (2) may operate in the event of other power outage, the power supply (4) comprises 30 a self-sustaining energy source such as a capacitor, solar panel, fuel cell, battery or combination thereof or any other suitable source or combination of sources. In an embodiment including a battery, an eight day battery pack is preferred. The eight day minimum energy source life may 35 result from a suitable combination of a chosen energy source with any or all of operating bandwidth, low power consumption system components, programmed system sleep modes, and preset sample rate. Regardless of the self-sustaining energy source used, the design of the data acquisition system 40 (2) is such that relatively low power levels are required for operation. During normal operation of external power supplies such as rig power, the power supply (4) may be charged.

Monitored parameters are those relevant to the operation, 45 condition and/or location of the rig during times of evacuation, partial evacuation, or failure of normal rig communication systems and may include longitude and latitude of the rig, roll, pitch of the rig, wave height and frequency, wind speed, wind direction, mooring line tension, rig generator 50 data and any other desirable parameter or any combination thereof. A sample data table is shown in FIG. 5. The data acquisition system (2) may support a plurality of parameter sensors (3). The plural sensors (3) may be redundant so that data may be verified or they may measure multiple param- 55 eters or they may do both. Sensors (3) may comprise inclinometers (tilt sensors), anemometers, current meters, thermometers, pressure sensors, load cells or any other suitable sensors (3) or combinations thereof.

Acquired data may be stored in a memory or other signal 60 bearing medium of the data acquisition system (2) or of a remote location (6) or both. In one alternative at least one stored data is time stamped with a date and/or time corresponding to the time at which the data was generated. Examples of data that have been date and time stamped (12) 65 are shown in FIG. 5. At least a portion of such data may be used either remotely or by a processor of the data acquisition

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system (2) to determine secondary data. Such secondary data comprises information that is relevant to the condition and/or location of the rig and in the event that the rig is moving may include rig speed and rig course. Examples of secondary data are shown in FIGS. 2, 3, and 4. FIG. 2 shows a rig location icon (7) plotted relative to a geographical map (8). Such a derived plot exemplifies some secondary data. FIG. 4 shows a geographic location plot or map (8) with a data set (10) linked to a user interactive rig icon (7). Examples of secondary data included in the data set (10) are Course Over Ground ("COG") (13) and Speed Over Ground ("SOG") (14). Optionally the data set of FIG. 5 may be linked to an interactive feature such as a rig icon (7). Optionally any data set may be linked to any interactive feature. Other interactive features may include a storm icon (20) and a storm track (21) shown in FIG. 3. Storm characteristic and tracking data may be linked to a storm icon (20) or a storm course plot icon (21) and displayed when the icon is activated. Storm data may be integrated with rig data to derive storm distance from and projected time until arrival at the rig. Such secondary data may also include a rig status summary indicator such as a warning. The warning indicates that a certain parameter has reached a critical value. An example of a parameter that may merit a warning is mooring line tension. A mooring line load cell (an example of a parameter sensor (3)) is disposed adjacent a mooring line so that it may measure line tension. When the line tension reaches a critical value such as yield point or actual failure a warning may be generated. Other critical values that may merit a warning include rig course collision (with another object) predicted, rig tilt exceeds acceptable angle, wind speed in excess of rig design rating, and wave height in excess of rig design rating. Such a warning may be visible or audible or both and is detectable by a user at the remote access member.

The remote data access member (5) is used from a location remote to the rig to access data acquired by the monitoring system (1). The member (5) may be an internet server, personal computing device, or data storage system located onshore or on another offshore facility or vessel and includes or is connected to a wireless communication system. The remote data access member (5) may comprise a node (15) in a network such as an internet. The remote data access member can selectively or continuously be communicatively connected to the rig monitoring system (1) preferably via a communication port (16). In one alternative the remote data access member (5) is a personal computing device such as a laptop computer. In such an alternative the personal computing device is used to access the communication port (16b) by direct analog phone line dial up. That phone line is then connected to the communication port (16a) and the data acquisition system (2) and data is automatically sent to the personal computing device in response to the call. In another alternative the remote data access member (5) comprises a plurality of remote data access members thereby allowing multiple to users to access data from one or more rigs from multiple remote locations (6).

The data acquisition system (2) has a communication port (16a) wherein the port (16a) is configured to send and receive signals to and from the remote location (5). In one alternative the port (16a) is co-located with the rig and is part of the data acquisition system (2) or is at a fixed location relative to the data acquisition system (2). The communication port (16a) may be configured to send signals to and receive signals from multiple remote locations. In one alternative the port (16a) may only send signals at a predetermined frequency or continuously.