Patent Description:
In the field of subsea engineering for the hydrocarbon production industry, it is known to provide flow systems comprising a subsea manifold connected to several flowlines from or to other flow infrastructure, for example from or to subsea wells. A typical subsea manifold has a plurality of spatially distributed connectors for tie-in of the flowlines, which may be jumper flowlines. During the development of subsea hydrocarbon fields, it is often the case that new hydrocarbon discoveries are made and/or further tie-ins to the flow system infrastructure are required. If an existing subsea manifold has no connectors available, new subsea infrastructure may need to be installed to enable the new well to be tied-in and to accommodate any further tie-ins which may be required in the future.

"Case studies in 'flow access module' applications providing multiple life of field solutions using standard Xmas trees and Manifolds" (presentation by Ian Donald at Subsea Expo <NUM>, Aberdeen, U. , Feb <NUM>), discloses a jumper termination apparatus for a subsea jumper flowline, wherein the jumper termination apparatus comprises an access interface. This access interface is vertically orientated and is configured to be connected to a termination apparatus of a second jumper flowline.

There is generally a need for a method and apparatus which addresses one or more of the problems identified above.

It is amongst the aims and objects of the invention to provide a method and/or apparatus for connecting subsea flowlines to a subsea manifold, which obviates or mitigates one or more drawbacks or disadvantages of the prior art.

Other aims and objects will become apparent from the following description.

According to a first aspect of the invention, there is provided a jumper termination head for a subsea jumper flowline, the jumper termination head comprising:.

The access interface may be oriented on an axis inclined to the main axis of the manifold connector, for example in a radial plane.

Alternatively, the access interface may have an axis of orientation which may be horizontal, or which may be inclined at an angle to the horizontal.

The second flow path may be inclined at an angle to the immediately adjacent portion of the jumper flowline.

The jumper flowline may comprise a composite jumper flowline.

The jumper coupling means may comprise a studded connection.

The jumper coupling means may comprise a curved gooseneck section which may be configured to be disposed between the body and the jumper flowline. The gooseneck section may be connected to the body and the jumper flowline by flanged connections.

The access interface may be configured to provide access for a fluid intervention or mechanical intervention operation on the flow system. Fluid intervention operations may be a fluid intervention operation from the group comprising: fluid sampling, fluid pumping, fluid diversion, fluid recovery, fluid injection, fluid circulation, fluid measurement fluid metering, artificial/gas lift, and/or well scale squeeze operations. Mechanical intervention operations may be cleaning and/or pigging operations.

In this context, connected means a physical interaction between two components. The connection may be directly or via an intermediate component. The access interface may be configured to be connected to a second jumper flowline directly. Alternatively, or in addition, the access interface may be configured to be connected to a second jumper flowline via a jumper termination head of the second jumper flowline.

The jumper termination head may comprise a guide funnel, and/or may comprise a cut-away or relief configured to accommodate the lower jumper flowline. The cut-away or relief may be in the guide funnel.

According to a second aspect of the invention, there is provided a method of connecting subsea flowlines to a subsea manifold, the method comprising:
providing a first jumper flowline having a first jumper termination head connected to a subsea manifold connector and comprising a first access interface, wherein the first jumper termination head comprises:.

The further jumper termination head may comprise a further access interface.

The method may also comprise connecting the first jumper termination head to the first subsea manifold connector, for example by an ROV-operated clamping action.

The method may comprise clamping the second jumper termination head to the first subsea manifold connector.

The second jumper termination head may comprise a guide funnel. The method may comprise orienting a cut-away or relief of the guide funnel to accommodate the first jumper flowline.

The further jumper termination head may comprise a guide funnel. The method may comprise orienting a cut-away or relief of the guide funnel to accommodate the second jumper flowline.

The method may comprise performing fluid intervention or mechanical intervention operations on the flow system via the first access interface, and/or the second access interface and/or the further access interface. Fluid intervention operations may be a fluid intervention operation from the group comprising: fluid sampling, fluid pumping, fluid diversion, fluid recovery, fluid injection, fluid circulation, fluid measurement fluid metering, artificial/gas lift, and/or well scale squeeze operations. Mechanical intervention operations may be cleaning and/or pigging operations.

According to a third aspect of the invention, there is provided a flow system for a subsea hydrocarbon production or injection installation, the flow system comprising:.

The subsea manifold may be a collection manifold.

The subsea manifold connector may be a male connector.

The connector coupling means may be a female connector.

The first and/or second jumper flowlines may comprise a composite jumper flowline.

The first and/or second jumper flowlines may be production jumper flowlines which may facilitate production flow from respective subsea wells into the subsea manifold.

The subsea manifold, and the first and/or second jumper flowlines may comprise multiple flow lines or flow bores. The first and/or second jumper termination heads may define a further flow path or flow paths which correspond to the multiple flow lines or flow bores of the subsea manifold and the first and/or second jumper flowlines.

Referring firstly to <FIG>, there is shown, generally at <NUM> a subsea production manifold tie-in system according to the prior art. The system comprises a subsea manifold <NUM>, which in this example is a collection manifold comprising a plurality of proprietary subsea connectors 16a for the connection of production jumper flowlines <NUM> from respective subsea wells. The subsea connectors 16a are male connectors of a proprietary vertical tie-in connection system, of which there are several types in the industry, and the jumper flowlines <NUM> are terminated with a jumper termination head comprising a corresponding female proprietary connector 16b. In this embodiment, the flowline being tied-in is a vertically-deployed jumper flowline <NUM>. <FIG> shows the system prior to the connection being made-up, and <FIG> shows the connection made up such that production flow from the jumper flowline can enter the manifold for onward processing, production, or transportation.

The manifold <NUM> also comprises a number of other connectors 16a, each available to be connected to connectors on additional jumper flowlines from other subsea wells. Subsea manifolds of this type can therefore accommodate a number of jumper flowlines, determined by the number of connectors on the manifold. However, during the development of subsea hydrocarbon fields, it is often the case that new hydrocarbon discoveries are made and/or further tie-ins to the production infrastructure are required. If an existing subsea production manifold has no connectors available, new subsea infrastructure must be installed to enable the new well to be tied-back and to accommodate any further tie-ins which may be required in the future.

Referring now to <FIG>, a subsea production manifold tie-in system is shown generally at <NUM>. The manifold <NUM> is the same as the manifold <NUM> of <FIG>, and comprises a number of connectors 16a for connection of jumper flowlines. However, the connection system between the jumper flowlines and the manifold is modified to provide additional flexibility of operation and/or increased connection capability, as will be described below.

The jumper flowline is terminated in a modified connector assembly <NUM>, comprising female connector 116b and access interface <NUM>. The female connector 116b is similar to the connector 16b, and enables the jumper flowline <NUM> and the manifold to be fluidly coupled to a manifold connector 16a. The access interface <NUM> comprises an additional access bore <NUM> which enables fluid and/or mechanical access to the inlet bore of the connector 16a, even after make-up with the jumper flowline <NUM>. The access bore is at an angle to the immediately adjacent portion of the jumper flowline, and is vertically oriented to enable access from above.

<FIG> shows the connection between the jumper flowline <NUM> and the manifold after it is made up, by engagement of the connector 16a and the connector 116b. The system <NUM> also includes a second jumper flowline <NUM>, terminated in a termination head <NUM> comprising a connector portion <NUM> configured for connection to the access bore <NUM> of the access interface <NUM>. The connector portion <NUM> comprises a guide funnel <NUM> comprising a cut out profile <NUM>, such that the guide funnel can be placed over the access interface <NUM> with the cut-out profile accommodating the installed jumper flowline <NUM>.

Internal to the guide funnel is a bore connection which enables the jumper flowline to be placed in fluid communication with the access bore <NUM>. An external clamp mechanism <NUM>, operable by an ROV, enables the connection to be made up as shown in <FIG>. The system <NUM> therefore comprises a dual jumper connection to a single manifold connector 16a, with the jumper terminations connected to the manifold in a vertically stacked arrangement. The system therefore increases the number of jumper flowlines that may be connected to the manifold, and/or alternatively provides flexible connection locations for jumper flowlines on the manifold. Such a configuration increases the connection capacity of existing subsea flow systems, reducing the requirement for additional subsea infrastructure.

The foregoing shows the vertically-stacked connection of a pair of vertically-deployed conventional steel jumper flowlines onto a single proprietary connector on a subsea manifold. However, it would be appreciated that alternative configurations of jumper system may be used. For example, the access interface may be oriented on an axis inclined to the main axis of the manifold connector, for example in a radial plane. The principles of the invention may be applied to horizontal manifold connectors or inclined manifold connectors, and/or the access interface may have an axis of orientation which is vertical, horizontal, or inclined.

Alternative embodiments of the invention may use alternative materials for the jumper system, and/or alternative geometries or configurations of the connection system in order to facilitate the connection of two jumper flowlines to a single manifold connector.

<FIG> is an example of a jumper connection system, generally depicted at <NUM>, having a jumper termination head and jumper arrangement, where the jumper flowline <NUM> is a composite jumper flowline provided with a studded inlet connection <NUM> to a body supporting the access interface <NUM>. As previously, the access interface <NUM> is arranged above a female connector <NUM> with an external clamp <NUM>, and is designed to connect onto a corresponding proprietary connector of the manifold. By using a composite material for the jumper flowline <NUM>, the overall weight of the jumper flowline and connector system may be reduced, compared to the weight of a conventional steel jumper flowline. This reduces the static load on the connector and manifold. In addition, the increased flexibility of the composite jumper flowline compared with the conventional steel jumper flowline may reduce the dynamic load on the connector and manifold.

<FIG> is a side view of a further alternative jumper connection system. In this connectoin system, the connector and jumper flowline system, generally shown at <NUM>, comprises a composite jumper flowline <NUM> connected to a block supporting an access interface <NUM> above connector <NUM> with an external clamp <NUM>. In this system, the composite jumper flowline forms a flanged connection <NUM> with a rigid, curved gooseneck section <NUM> disposed between the block and the jumper flowline. The system <NUM> offers the load reduction benefits of the system <NUM>, and the gooseneck portion may provide an improved position of the composite jumper flowline, and further reduce the static and/or dynamic loads on the connector and manifold.

The load reduction benefits described above maybe significant in some applications of the invention to mitigate the effect of increased loads due to additional connectors connecting at a single point on the manifold. Alternatively, or in addition, the load reduction benefits may enable landing and/or installation of additional equipment on the manifold before its load bearing capacity is exceeded.

Although the foregoing shows a pair of vertically stacked jumper connectors, it will be appreciated that three or more jumper flowlines may be connected onto a single manifold connector, for example by vertical stacking of third and further jumper termination heads. According to the invention, this can be implemented by providing a second jumper termination head with a second access interface, configured for the connection of a further jumper termination head. Third and further jumper termination heads maybe similarly configured to enable continuing connection (e.g. by stacking) of jumper flowlines on a single manifold connector. In such implementations of the invention, reducing the static or dynamic loads by the use of composite jumper flowlines and/or flowline geometries may be beneficial.

The access interface of a jumper termination head may be used to provide access for a fluid intervention or mechanical intervention operation. Such fluid intervention operations may be selected from (but are not limited to) fluid sampling, fluid pumping, fluid diversion, fluid recovery, fluid injection, fluid circulation, fluid measurement fluid metering, artificial/gas lift, and/or well scale squeeze operations. Mechanical intervention operations include but are not restricted to cleaning and/or pigging operations.

The jumper termination head may be a modified jumper termination head, modified to include the access interface and a flow path connecting the access interface to the subsea manifold connector or a flow path between the subsea manifold connector and the jumper flowline coupling. Alternatively, the system may be provided with an adaptor hub which is configured to be connected between the jumper flowline and the subsea manifold connector (for example between the jumper termination head and the subsea manifold connector, or between the jumper termination head), and which provides the access interface.

The jumper termination head, or jumper termination head assembly, may comprise multiple flow lines or flow bores extending therethrough, to correspond to multiple flow lines or flow bores present in the flow system. For example, a connector on the subsea manifold may incorporate production flow lines and injection or artificial lift flow lines, and the jumper may be similarly configured. The jumper flowline connection system may comprise a set of parallel flow lines configured for connection of the respective lines between the subsea tree and the jumper, and at least one of the parallel flow lines may be provided with an access interface for another flow stream directed in or out of the flow system (e.g. production fluid being brought in from another subsea tree), or as an access interface for fluid or mechanical intervention as described above.

The invention facilitates connection of multiple flowlines, for example by daisy-chaining flowlines, into flow systems with a limited number of connection locations, reducing the requirement to add subsea flow infrastructure.

Claim 1:
A jumper termination head (<NUM>) for a subsea jumper flowline, the jumper termination head comprising:
a body;
a jumper coupling means configured to couple the body to a jumper flowline (<NUM>); and
an interface coupling means (<NUM>) configured to couple the body to a vertically oriented access interface (<NUM>, <NUM>, <NUM>) of a lower jumper termination head (<NUM>) of a lower jumper flowline (<NUM>, <NUM>, <NUM>) in a vertically stacked arrangement;
wherein the lower jumper termination head comprises a body coupled to a subsea manifold connector (16a) and the body defines a first flow path from the coupled jumper flowline to the coupled subsea manifold connector, and a second flow path from the vertically orientated access interface to the subsea manifold connector;
wherein the jumper termination head (<NUM>) is configured to be coupled to the vertically orientated access interface (<NUM>, <NUM>, <NUM>) of the lower jumper termination head from above in the vertically stacked arrangement;
wherein the jumper termination head (<NUM>) comprises an upper access interface;
wherein the body of the jumper termination head (<NUM>) defines a first flow path from the coupled jumper flowline (<NUM>) to the interface coupling means, and defines a second flow path from the upper access interface to the interface coupling means;
and wherein the upper access interface enables the connection of a further jumper flowline, and/or enables fluid intervention or mechanical intervention operations on the flow system via the upper access interface and the vertically orientated access interface (<NUM>, <NUM>, <NUM>) of the lower jumper termination head.