IES83841Y1 - A pipeline apparatus - Google Patents

Abstract

ABSTRACT An autonomous pipeline apparatus (100) for use in detecting buckles or deformations of a pipeline (1 1) during a pipe lay operation. The pipeline apparatus (100) comprising a vessel having a first end, a second end and an elongate body intermediate the first and second ends, the body of the Vessel having an interior and exterior surface. Hydraulic means (5) are positioned within the body of the vessel. The vessel has an attachment piece (7) at the first end and a retaining mechanism (9) positioned along the exterior surface of the elongate body, the retaining mechanism (9) being operable by the hydraulic means (5) to engage with the interior surface of the pipeline and by a battery powered motor (13) for propelling the autonomous pipeline apparatus (100) along the inside of the pipeline (1 l). The attachment piece optionally being a gauging plate (7) or an isolation plug (400). The gauging plate (7) being used to determine if the pipeline is damage free after being laid.

Description

P10528.IES A PIPELINE APPARATUS The present invention relates to an apparatus for pipelines and in particular to an autonomous pipeline apparatus with attachments.

Offshore oil and gas products are brought to shore via subsea transportation systems which are primarily composed of long lengths of pipe known as pipelines. Various pipe lay operations are conducted to install pipelines on the seabed.

One such operation uses pipe lay barges which crab along the seabed on anchors. Lengths of pipe are welded together to construct pipelines on the barge. The pipeline is laid on the seabed as the barge crabs its way forward. Typical examples of lay barges are Seamac, Castoro 6, Castoro 10, and Tog Mor.

For deeper water, or areas of the seabed that are congested due to the presence of other pipeline networks, lay barges using anchor systems cannot be used. Instead dynamically positioned lay vessels, such as Solitaire, Lorelay and Saipem 7000 which do not require anchors are used.

Other methods of installing pipelines include preparing the pipelines on land and then transferring the prepared pipeline to the desired off-shore location.

One example of this type of operation involves pre-fabricating a collection of various sized pipelines and umbilicals together and containing them within an outer casing on shore. The pipelines and umbilicals together in the outer casing area known as a bundle, examples of bundle operations include Wick or Orkanger. The bundles are pulled into shallow water prior to being towed to the off-shore location. In shallow waters the bundle is suspended under two tug boats and ballasted by chain weights. The bundle is transported to its pre- determined location by towing offshore using a Controlled Depth Towing Method (CDTM).

Alternatively, the pipeline can be laid from a reel pipelay vessel such as Deep Blue, Skandi Navica l6, Seaway Falcon 16 and Seaway Kestrel l4. Rigid steel pipe up to 18 inches in diameter and 20mm wall thickness can be laid from these types of vessel. The rigid steel pipe is spooled onto the vessels reel at the shore—side pipe base. The vessel then sails to the predetermined off-shore location and the pipe is spooled off the reel through tensioners where it is straightened, before it is over-boarded and laid on the seabed.

If the pipeline length required is longer than the amount on the reel, the lay vessel will return to port, there, additional pipe is spooled onto the reel. The vessel then sails back to the location where the initial pipeline end is recovered. The two pieces of pipe are welded together thereby extending the pipeline. Additional lengths of pipe are added as required.

Generally pipe lay operations are performed by a separate company to the oil or gas company. The pipe lay contractor must deliver a pipeline to the oil or gas company without any buckles or deformations.

Traditionally, on completion of a pipe lay operation, a pipeline tool (a pig) containing a sectored gauging plate is pushed from the start up head of the pipeline with fluid. The gauging plate is sized to approximately 95% of the pipeline internal diameter. When the gauging pig is received at the end of the pipeline, its sectored gauge plate is checked to ensure that it contains no nicks, deformations or bends. If the gauge plate is damage free, the pipeline is accepted as being free of buckles or dents, by the pipeline integrity assessor from the oil or gas company. If the pipeline has buckles or dents the assessor will not accept the pipeline for the oil or gas company, until the impediments are removed.

Removal of a buckle or dent from a laid pipeline may involve enormous time, expense, and risk. The pipeline may have to be recovered to remove the buckled section, this can prove to be extraordinarily difficult especially if the entire pipeline is flooded. Alternatively, the buckled pieces may be cut out and a hyperbarically welded piece is positioned as a replacement.

A number of different solutions have been proposed to provide a more efficient real time method of detecting buckles or dents described for each of the pipe lay operations. During pipe lay from a lay barge or dynamically positioned vessel, a gauging plate can be towed on a fixed line behind and attached to a line up clamp. This gauge plate and its associated strain gauge provide real-time positive indication of pipe buckle, and the damaged pipe can be recovered immediately, resulting in low risk and reduced loss of pipe and time.

Prior to pulling bundles into shallow water the pipeline sections within the bundle are pigged and gauged to ensure that they are buckle free. The protecting outer casing on the bundle then assures the integrity of the encapsulated pipelines within the bundle.

On some vessels it is also possible to detect a break in the pipeline causing water to flood into the pipeline. This is known as a wet buckle. The technology used is known as an "Exit Monitoring System", which constantly reads lay tension. A wet buckle results in an instantaneous increase in weight of pipe from loss of buoyancy hence an increase in the lay tension, this is what the monitoring system records.

Currently there is no method of gauging whilst laying a pipeline to ensure that a rigid reeled pipeline, is buckle free, without filling the pipeline with either liquid or gas.

Furthermore it is not possible to isolate a pipe during pipe lay from a rigid reel vessel, especially if the pipe has a wet buckle. Currently if such an event was to occur loss of the pipeline would be inevitable.

It is an object of the present invention to seek to alleviate the above disadvantages.

Accordingly, the present invention provides an autonomous pipeline apparatus, comprising a vessel having a first end, a second end, an elongate body intermediate the first and second ends, the body of the vessel having an interior and exterior surface, a hydraulic means within the vessel, the vessel having an attachment piece at the first end and a retaining mechanism positioned along the exterior surface of the elongate body, the retaining mechanism being operable by the hydraulic means to engage with the interior surface of the pipeline and a battery powered motor for propelling the autonomous apparatus along the inside of the pipeline.

Advantageously the attachment piece comprises any one of a gauging plate, callipers or isolation plug.

Preferably the autonomous apparatus further comprises a control system.

Ideally a location detector is also provided on the autonomous apparatus.

Conveniently the retaining system comprises either a plurality of rubber wheels or a rubber wheel and track combination. This enables the autonomous apparatus to grip the interior surface of the pipeline and travel therein whilst maintaining traction.

Ideally the retaining system comprises a plurality of rubber wheels when the autonomous apparatus is used within a straight pipeline without any alterations in the internal pipeline dimensions.

Alternatively the retaining system comprises a rubber wheel and track system when the autonomous apparatus is used within a pipeline that has tee pieces or other appurtenances fitted which alter the internal pipeline diameter.

Preferably the battery driven motor comprises a plurality of battery driven high torque electric motors on an open differential Ideally power is provided by lithium ion batteries however any suitable power supply known to a person skilled in the art can be used.

Preferably there are four high torque electric motors however the invention is not limited to this number of electric motors. Advantageously the electric motors provide propulsion to the vessel of the autonomous apparatus enabling the apparatus to move at a continuous speed within the pipeline. Conveniently the gauging apparatus moves at a speed of 500 meters per hour (25 feet per minute).

Advantageously the autonomous apparatus can travel through pipelines which are at an inclination of up to 90°. Conveniently the hydraulic system provides an outward radial force to the pipelines interior surface causing the retaining system to engage with the interior surface. Simultaneously the electric motors provide a torque to the retiaing system enabling the gauging apparatus to move up the pipeline. The torque applied is dependent on the outward radial force and the diameter of the wheels of the retaining system.

Advantageously the motor speed and torque are easily adjusted using speed reducers and/or adjusting the size of the wheels of the gripping system. Conveniently if the diameter of the wheels of the gripping system is increased a larger torque is needed, however there are fewer motor rotations as the autonomous apparatus moves more quickly through the pipeline.

Preferably the control system has means for communicating with a remote unit. Ideally the control system starts and stops the electric motors by responding to signals from the remote unit using an isotope wand principle. Preferably the remote unit is fitted with a radioactive source such as Cesium 137. Ideally movement of the remote unit is detecting using a scintillating detectors tuned for frequency recognition of specific radioactive isotopes disposed in the control system. Preferably if the remote unit approaches in a first direction, for example from left to right, the scintillating detectors detect the direction of the movement, the control system switches the autonomous apparatus on and the autonomous apparatus moves in the pipeline. Conveniently if the remote unit moves in a second direction which is opposite to the first direction, the control system switches the autonomous apparatus off and movement stops.

Ideally the control system is housed in a pod on the autonomous apparatus.

Ideally the location detector comprises a radioactive source. Conveniently the radioactive source of the location detector is different to the radioactive source of the remote unit, therefore it does not interfere with the control system. Preferably the location detector is used to detect the autonomous apparatus in the event of failure of the control system.

Advantageously the autonomous apparatus is made from light weight materials so that the cumulative weight of the apparatus is less than the wheel co—efficient of the function forcing the apparatus to move within the pipeline. Ideally the materials used include aluminium 6082 or 6A14V (please define) The materials are not limited any appropriate material known to a person skilled in the art can be used.

Advantageously the apparatus of the invention is readily adapted to fit pipelines with different internal diameters.

Advantageously in a first embodiment of the apparatus of the invention, the vessel is fitted with a gauge plate attachment.

Advantageously the gauge plate comprises a sectored gauge plate which is sized to meet specific customer requirements. Preferably the gauge plate is made from light weight aluminium, for example aluminium 6082.

Advantageously in a second embodiment of the apparatus of the invention, the vessel is fitted with an isolation plug attachment. Conveniently the isolation plug attachment comprises a cylindrical vessel with sensors, locking grips and sealing members and a plate member wherein the locking grips and sealing members encircle the cylindrical vessel wherein a hydraulic pump operates the piston and wherein the plate member incorporates a master dump valve.

Preferably the actions of the piston and the sensors are communicable through the pipeline to the control system of the vessel using extremely low frequency magnetic waves. Ideally the magnetic waves are detectable and transmittable using an aerial array cluster.

Conveniently when the sensors detect the presence of water, the piston is activated and the locking members and sealing members engage to block and isolate the pipeline.

Advantageously in a third embodiment of the apparatus of the invention, the vessel is fitted with a calliper attachment.

Ideally when any one of the attachment pieces are attached to the vessel, the apparatus is installed into the head of the pipeline prior to the pipeline being laid. Once the apparatus is installed the head of the pipeline is overboarded at the desired location, the apparatus is then activated. Ideally the apparatus moves through the pipelines at the same speed as the pipeline is laid. Conveniently the apparatus is positioned beneath the surface of the water where it is easily located by the remote unit. Ideally the apparatus is located between the splashzone and touchdown areas of the sea, where the splashzone is defined to be the turbulent area of water at the surface of the sea where the pipeline enters the sea and the touchdown area is defined to be the calmer area at the seabed where the pipeline rests or on which the pipeline rests prior to it’s burial or trenching. If the pipeline buckles, the apparatus stops as it cannot pass through the buckled area. The remote unit detects that the apparatus has stopped. The buckled section is recovered to the surface for inspection and repair after which pipe laying continues.

If the pipeline has a wet buckle and the isolation plug is attached to the vessel, the isolation plug sensors detect the ingress of the water and seal the pipeline. Conveniently the pipeline is sealed between 0 to 2.9 seconds. Advantageously the pipeline is then recovered to the surface for repair. Conveniently the isolation plug attachment can be deactivated by activating a master dump valve on the isolation plug.

Alternatively if either the gauge plate or the callipers are attached to the vessel and if the apparatus reaches the end of the pipeline on completion of pipe lay without a damaged gauge plate or callipers the pipeline has been laid without damage and is free from impediments. Therefore the pipeline can be laid and tested to be buckle free without filling the pipeline with either liquid or gas.

Conveniently if the apparatus has a mechanical failure during the operation the apparatus can be removed from the pipeline using a chased pigging tool.

The invention will now be described more particularly with reference to the accompanying drawings, which show by way of example only, two embodiments of an autonomous pipeline apparatus of the invention.

In the drawings: - Figure 1 is a cross sectional plan view of a first embodiment of the apparatus of the invention with a gauge plate attachment; Figure la is a cross sectional perspective View from a first side of the embodiment of the apparatus of the invention with a gauge plate attachment; Figure lb is a cross sectional perspective view from a second side of the embodiment of the apparatus of the invention with a gauge plate attachment; Figure 2 is a cross sectional plan view of the first embodiment of the apparatus of the invention in position in an angled pipeline with a gauge plate attachment; Figure 3 is a cross sectional plan view of the first embodiment of the invention in position in a vertical pipeline with a gauge plate attachment; Figure 4 is a plan view of a second embodiment of the apparatus of the invention with an isolation plug attachment; Figure 5 is a plan view of a the second embodiment of the apparatus of the invention with an isolation plug attachment in an unactivated state in a pipeline; and Figure 6 is a plan view of the second embodiment of the apparatus of the invention with an isolation plug attachment in a activated state in the pipeline.

Referring initially to Figures 1 to 3 there is shown a first embodiment of an autonomous apparatus 100 with a gauge plate attachment 7. The apparatus 100 uses onboard lithium ion batteries 1 to drive four high torque electric motors 13 on open differential, which provide propulsion to wheels/tracks 9 to move the apparatus inside a pipeline 11 at a continuous speed of approximately 500 metres per hour (25 feet per minute).

The autonomous apparatus 100 has a hydraulic system 5 which pushes the rubber wheels/tracks (Figures 1, la, lb and 2, 9) of rubber wheels (Figure 3, 109) onto the pipe wall 11 regardless of the orientation of the apparatus 100. The hydraulic system 5, and rubber wheel/track system (Figures 1, la, 1b and 2, 9) or rubber wheels (Figure 3, 109) therefore enable the apparatus 100, to travel up inside steel pipelines 11 maintaining traction and without slipping. The pipeline 11 can be positioned at any angle between 0° to 90° relative to a horizontal axis. The wheel/tracks 9, 109 encircle the vessel so that wheel/tracks 9, 109 are in contact with the interior circumferential surface of the pipeline The apparatus 100, is configured so that the cumulative weight of the apparatus 100, is less than the tyre/track co-efficient of friction forcing it onto the pipeline wall 11, enabling the apparatus to progress up the pipeline wall at an inclination of up to 90°.

The gauge plate 7, can be sized to meet customer requirements for 95% of the pipeline internal diameter, or as per the pipe lay specification in use.

The control system 3 switching is activated and de-activated by scintillating detectors (not shown) which start and stop the motor 13 The gauging apparatus 100, scintillating detector control switching system works on the Isotope wand principle. The scintillating detectors are tuned to 662 KeV (the resonating frequency for Cesium 137). The remote unit (not shown) located outside the pipeline, is fitted with a Cesium 137 source. When the remote unit approaches left to right, the scintillating detectors detect this and the motor 13 inside the pipeline 11 switches on, and drives the apparatus 100. When the remote unit approaches right to left, the motor 13 switches off and stops the apparatus 100.

The apparatus 100, 200 is also fitted with a radioactive source Figure 3, 15. This is Iridium 192 which resonates a t(3l7 and 468 KeV) which are different KeV frequencies and thus does not affect the on/off control system of the scintillating detectors. The purpose of this Iridium 192 source is to detect the location of the apparatus 100, under failure conditions.

The Iridium 192 source on the apparatus 100, is detectable by the remote unit which is fitted with a scintillating detector tuned to 317 and 468 KeV.

The control pod 3, on the apparatus 100, has dedicated suitable software to reliably control all functions of the movement of the apparatus 100.

The scintillating detectors mounted on the remote unit are tuned to enable the remote unit to quickly detect the presence of the apparatus 100, inside the pipeline against normal background radiation.

In use the apparatus 100, is installed inside the pipeline ll lay down head, prior to the lay down head being installed. The apparatus 100, is activated to crawl through the pipeline 11, as the lay down head is overboarded, so that the apparatus 100, takes up a position beyond the splash zone where its location can be easily identified by the remote unit.

The apparatus 100, maintains the same speed as the pipe lay, and should the pipe lay be too slow, the apparatus 100, is stopped. The velocity of the apparatus 100, is always configured to meet maximum vessel pipe lay speeds.

If a buckle is detected by the gauge plate 7, then the apparatus 100 will stop, as it cannot pass. If the remote unit detects that the apparatus 100 has stopped, then the remote unit investigates. The buckled section is recovered to surface, for inspection and/if required repair.

If the apparatus 100 reaches the end of the pipeline 11 on completion of pipe lay, without a damaged gauge plate 7 the line has been laid unbuckled.

In the event that the apparatus 100 has a mechanical breakdown during its gauging operation, then the apparatus 100 is pigged out of the line, by using a chaser pig.

Referring to Figures 4 to 6 there is shown a second embodiment of the autonomous apparatus 300 with an isolation plug attachment 400. The autonomous apparatus 300 operates as previously described, however the tracking system 140 comprises a plurality of wheels 110 attached to the vessel of the autonomous apparatus 300 by means of spring 111. Furthermore in this second embodiment of the autonomous apparatus 300 the control system is housed in a control pod 203 intermediate the autonomous apparatus 300 and the isolation plug 400.

The isolation plug attachment 400 comprises a closed hydraulic system (not shown), sensors 134, a packer seal 132, a grip bearing ring 133, a grip segment 131 and wheels 130a, 130b. The closed hydraulic system is centrally situated within the isolation plug attachment 400. Figures 5 and 6 provide views of the isolation plug attachment 400 in an unset and fully set configuration within the interior of an angled pipe. In Figure 5 the isolation plug attachment 400 is in an unset configuration when sensors 134 detect the presence of water a signal is sent to the control system using extra low frequency technology, the piston within the closed hydraulic system is activated. The grip segment 131 which encircles the hydraulic system is forced into contact with the interior circumferential surface of the pipe wall 11. Further activation of the piston causes the packer seal 132 into contact with the interior circumferential of the pipe wall 11.

The buckled section is recovered to surface, for inspection and/if required repair. The isolation plug is disengaged by releasing the master dump valve (not shown). In the event that the apparatus 300 has a mechanical breakdown during its isolation operation, then as before the apparatus 300 is pigged out of the line, by using a chaser pig.

It will of course be understood that the present invention is not limited to the specific details herein described which are given by way of example only, and that various alternations and modifications may be made without departing from the scope of the invention.

MACLACHLAN & DONALDSON Applicants’ Agents Merrion Square Dublin 2

Claims (5)

CLAIMS:

1. An autonomous pipeline apparatus, comprising a vessel having a first end, a second end, an elongate body intermediate the first and second ends, the body of the vessel having an interior and exterior surface, a hydraulic means within the body of the vessel, the vessel having an attachment piece at the first end and a retaining mechanism positioned along the exterior surface of the elongate body, the retaining mechanism being operable by the hydraulic means to engage with the interior surface of the pipeline and by a battery powered motor for propelling the autonomous pipeline apparatus along the inside of the pipeline.

2. An autonomous pipeline apparatus as claimed in Claim 1, wherein the retaining mechanism includes either a plurality of wheels to engage with the interior surface of the pipeline or a wheel and track combination to engage with the interior surface of the pipeline; the battery powered motor comprising a plurality of battery powered high torque electric motors; the pipeline apparatus further comprising a control system; the control system further comprising a remote unit and means for communicating with the remote unit whereby the control system starts and stops the electric motors by responding to signals from the remote unit; the control system and remote unit communicating by means of an isotope wand means; the remote unit being fitted with a first radioactive source; the first radioactive source being Cesium 137; movement of the remote unit being detected using one or more scintillating detectors disposed in the control system; and the pipeline apparatus further comprising a location detector; the location detector comprising a second radioactive source; the second radioactive source being Iridium 192.

3. An autonomous pipeline apparatus as claimed in any one of the preceding claims wherein the attachment piece comprises any one of either a gauging plate, a callipers, or an isolation plug; the gauging plate comprising a sectored gauge plate; the isolation plug comprising a cylindrical vessel with sensors, locking grips, sealing members and a plate member wherein the locking grips and sealing members encircle the cylindrical vessel, wherein a hydraulic pump operates the piston and wherein the plate member incorporates a master dump valve; the actions of the piston and the sensors being communicable to the control system on the autonomous pipeline apparatus using extremely low frequency magnetic waves; the low frequency magnetic waves being detectable and transmittable 20 using an aerial array cluster; the locking members and sealing members engaging to block and isolate the pipeline when the sensors detect the presence of water and the piston is activated.

4. An autonomous pipeline apparatus as claimed in any one of the preceding claims, wherein the hydraulic means provides an outward radial force to the pipelines interior surface causing the retaining mechanism to engage with the interior surface, simultaneously the electric motors provide a torque to the retaining mechanism enabling the pipeline apparatus to move at a constant speed within the pipeline and optionally wherein the autonomous pipeline apparatus travels through pipelines which are at an inclination of up to 90° relative to the surface of the water and optionally wherein the pipeline apparatus can be removed from the pipeline using a chaser pigging tool in the event of mechanical failure.

5. An autonomous pipeline apparatus substantially in accordance with any of the embodiments as herein described with reference to and as shown in the accompanying drawings. MACLACHLAN & DONALDSON Applicants’ Agents