Patent Application
20150110564
The invention relates to the field of structures, such as offshore structures, associated apparatus and methods. In particular, though not exclusively, the invention relates to offshore structures, such as wind turbine structures, for example, piles for offshore wind turbines, and associated apparatus and methods.
During installation of an offshore wind farm, supporting piles are driven into the seabed in order to support each tower, nacelle and turbine. These piles are generally transported to the desired location, and then hammered into position using a pile hammer, which mechanically connects with the upper region of the pile.
There is an increasing concern that the noise emitted during this hammering process is harmful to the environment, and in particular the subsea environment.
In addition, unfavourable or adverse weather conditions can reduce the opportunities and time windows when such piles and other offshore apparatus can be deployed. In some regions, such as Northern Europe, the cost and risks associated with deploying such piles, and other offshore apparatus, can be higher due to such variable and seasonal weather conditions, which may give rise to pitching, rolling, etc., of any deployment vessels. Such movement may not only be detrimental to the success of the project, but also potentially hazardous to equipment and persons.
The problems associated with such variable and seasonal conditions can be exacerbated when deploying such structures in deeper waters (e.g. 40, 50 or 60 meters, or more), which may be further away from shore.
Furthermore, transporting piles, and/or other such offshore equipment, to and from offshore sites can also be expensive due to the need to store a significant amount of equipment on a vessel (e.g. on the deck of a vessel). Any reduction in the space requirements of such equipment can help reduce costs.
It will also be appreciated that in some cases, the water depth in which such piles (or other such supports) are located can very from site to site. For example, some offshore sites may be based in water depths of 10 metres or less, while others may be in water depths of 50 metres or more, which can cause problems when choosing the appropriate piles, supports, equipment and other tools needed for each site.
The problems associated with installing supporting piles, or like, may also be present when constructing other structures offshore, including bridges, harbours, coastal walks, oil and gas structures, or the like.
There is a need to address some or all of these background issues.
It should be noted that this background merely serves to set the scene to allow a skilled reader to better appreciate the following description. Therefore, none of the above discussion should necessarily be taken as pertaining to known prior art, or common general knowledge in this field.
According to a first aspect of the invention there is provided a guide apparatus, such as a guide apparatus for an offshore pile, or the like.
The apparatus may be configured to provide an acoustic, or pressure, barrier between a pile and a surrounding body of water, during deployment of a pile (e.g. locating a pile in the seabed). The acoustic barrier may provide an acoustic impedance mismatch between the pile and surrounding water (e.g. a barrier to acoustically decouple a pile from the water). The acoustic barrier may be configured to dampen (e.g. absorb, or at least attenuate) pressure waves that would otherwise be communicated from a pile to surrounding water.
The apparatus may be configured such that the acoustic barrier surrounds (or at least substantially surrounds) some, or all, of a pile, when being deployed. The barrier may be configured so as to surround, or substantially surround, the length of a pile.
The apparatus may comprise one or more pumps configured to displace fluid from a gap (e.g. an annular gap) between the guide apparatus and an offshore pile (e.g. to dewater the gap, such as dewater and provide a gas gap). The acoustic barrier may comprise a dewatered gap. The apparatus may be configured such that the offshore pile is located within the guide apparatus (e.g. fully or partially within guide apparatus).
The apparatus may comprise one or more seals configured to seal the guide apparatus with a pile located with the apparatus. The one or more seals may be configured to prevent fluid entering the gap (e.g. from a body of water to the gap).
The guide apparatus may be configured to allow a pile to be located within the apparatus (e.g. centrally within, such as concentrically within, the apparatus). The guide apparatus may comprise one or more centralisers. The centralisers may be configured to hold, and/or guide, a pile in a particular orientation with the guide apparatus, such as concentrically with the apparatus. The centraliser may be configured as actuatable arms, such as hydraulic arms. The arms may be configured to extend and/or retract in order to hold/guide a located pile. The arms may be configured to acoustically decouple a pile from the apparatus.
The centralisers may comprise radial members, such as a radially extended cones or vanes. The radial members may define an aperture to allow for positioning and/or maintaining of a pile within the guide apparatus.
The guide apparatus may comprise a guide cone on an upper region thereof. The guide cone may be configured to allow for, and assist with, a pile to be located with the apparatus (e.g. lowered and located within the apparatus).
The guide apparatus may be considered to comprise a guide portion. The guide apparatus may comprise a piling template. In use, the piling template may be configured to be positioned on a water floor (e.g. seabed, or the like). The piling template may be configured to stabilise the apparatus on a water floor. In some case, for example when the apparatus comprises a guide portion, the template may provide, or be configured to provide, a ballast for such a guide portion.
The guide portion may be configured to locate, and be positioned with, the template to allow for guiding of a pile to the water floor. The apparatus may be configured such that, in use, the guide apparatus (e.g. guide portion) extends above, and out of, the water. The guide portion may be configured as a sleeve.
In examples comprising one or more seals, one, some or all of those seal(s) may be positioned at a lower region of the guide apparatus (e.g. at a lower region of the guide portion). The seal(s) may be annular (e.g. one or more tyre seals). The seal(s) may be inflatable and/or deflatable. The seal(s) may be configured to allow a located pile to translate with respect to the seal. In such cases, the seal may still provide sealing. In similar words, the seals may be configured to seal the apparatus with the pile, yet not grip that pile to an extent that would significantly inhibit movement of that pile when being deployed, such as hammered into the seabed.
The guide apparatus may comprise a constriction, such as a region of reduced annular diameter. The constriction may be associated with one or more of the seals (e.g. at a region near, adjacent, etc. the seal(s)). The constriction may assist with locating a pile with the apparatus. The constriction may allow for a minimal gap (e.g. about 50 cm, about 25 cm, about 10 cm, about 5 cm, or about 1 cm) to exist between a seal and a located pile (e.g. prior to inflation).
The apparatus (e.g. the acoustic barrier) may comprise a dampening structure or material. The dampening structure or material may be configured to provide a difference in acoustic impedance between the apparatus (e.g. the guide portion) and surrounding water. The dampening structure or material may be provided as a coating, which may be provided on the inner and/or outer of the apparatus (e.g. in the inner and/or outer of the guide portion). The dampening structure or material may comprise a substrate having a plurality of gas-filled compartments or pockets (e.g. bladders). The dampening structure or material may be configured as a jacket (e.g. a wrapable jacket) for the guide apparatus, or guide portion.
The piling template may comprise one or more guide sockets. Each guide socket may be configured to allow for location of a guide portion with the piling template. The guide socket(s) may be configured to align, or position, a pile being deployed with a desired location to be deployed.
The guide apparatus may be configured to allow for movement of the guide portion between one or more of the guide sockets. For example, the apparatus may be configured to allow for raising and lowering of the apparatus/guide portion. In such cases, the apparatus may be configured to move the guide portion from a first position, associated with a first guide socket, to a second position associated with a second guide socket. In such examples, the apparatus may be configured to ensure that the guide portion is aligned with the first socket when in the first position and also aligned with the second socket when in the second position.
The guide sockets may be separated or spaced from one another, such as radially and/or circumferentially separated, on the piling template. The apparatus may be configured to move the guide portion in an arcuate manner between first and second position. The apparatus may be configured to move the guide portion between further positions/sockets (e.g. three, four, five and more). The piling template may comprise one or more stabilisers, to stabilise and/or orientate the apparatus with a water floor.
The, or each, stabiliser may have a stowed configuration and a deployed configuration. When deployed, the stabilisers may permit the apparatus to remain stable on, for example, a seabed. In the deployed configuration, the stabiliser may have been rotatably moved from a stowed configuration. Each stabiliser may be configured to be able to be locked, or retained, in the deployed configuration.
The sockets and/or guide portion may be able to be moved relative to the stabilisers (e.g. so that they can be more suitably vertically aligned in cases of an uneven seabed). The apparatus may comprise a main frame, which connects the guide portion and/or sockets, and which is configured to be moveable with respect to the stabilisers. The movement may be controllable. The apparatus may comprise a gimbling system to effect movement, which may be a controllable gimbling system.
The guide portion may be separable to allow a pile to be positioned within the guide portion. The guide portion may comprise an open configuration, and a closed configuration. The guide portion may be opened and closed, for example, along a lengthwise body axis (i.e. so as to allow the insertion of a pile from the side of the apparatus, rather than being lowered into the apparatus).
The guide portion may comprise two or more segmented portions (e.g. circumferentially segmented), at least one of which may be movable so as to open and close around a pile. The apparatus may comprise three segmented portions.
The guide portion may comprise a separable frame, configured to open to allow insertion and/or removal of a pile (or other driven structure) from the apparatus.
When in a closed configuration, the guide portion may surround a pile being deployed.
The apparatus may be configured to allow the guide portion to couple, or mate, with some or all of the sockets. The apparatus may comprise complementary mating elements, such as a lip and groove, to allow the guide portion to couple/mate with a particular socket (e.g. when the guide portion has been closed).
The guide portion may be configured such that, when moved to closed configuration the segments couple with a complimentary element of the socket (or other feature on the template).
The guide portion may comprise an acoustic dampening structure (e.g. material). The dampening structure may be provided on an inner and/or outer surface of the guide portion. In some example, the dampening structure may be provided at least on an inner surface thereof. For example, the apparatus may comprise dampening material configured to provide a difference in acoustic impedance between the inner annulus of the guide portion, and surrounding water (e.g. without the use a pump/seal).
The dampening structure may be configured to attenuate acoustic transmission from a pile to a body of water. In examples that use an opening/closing guide portion, then the dampening structure may be configured to attenuate acoustic transmission when the guide portion is in a closed configuration around a pile.
The guide portion may be configured such that the dampening structure abuts against a pile when located. For example, after closing the guide portion, the apparatus may be configured such that the dampening structure interfaces against a pile. In some cases, the process of closing the guide portion may be considered to urge water from an inner annulus of the guide portion (e.g. forcing water out of the annulus).
An intended interface surface of the dampening structure may be configured for reduced friction (e.g. using bristles on the interface surface, or a lubricious material, or the like). An intended interface surface of the dampening structure may be configured to allow for translating vertical movement of the pile within the guide portion (e.g. using rollers, or the like, on the interface surface).
The dampening structure may comprise one or more gas-filled pockets, or the like, or closed-cell foam, or the like.
Some or all of the dampening structure may be compressible against a pile in order to couple to a pile. Such a configuration may also assist in removing water from around a located pile.
The dampening structure may comprise a plurality of gas-fillable compartments, pockets or bladders. The bladders may be inflatable and/or deflatable. The guide portion may be configured with a plurality of bladders, which may be spaced both circumferentially and/or lengthwise along the inside of the guide portion. Some or all of the bladders may be configured in rings, or the like.
Some or all of the bladders may additionally comprise an outer friction surface or sleeve, having an interface surface to allow reduced friction contact with a pile (e.g. comprising bristles, or the like).
The apparatus may be configured to provide gas bubbles between a pile and the guide portion (e.g. between the dampening structure and a pile). The apparatus may be configured such that gas bubbles are adhered or retained to or with the outer friction surface (e.g. between the bristles of the outer friction surface).
In some examples, the dampening structure need not couple (e.g. touch) to a located pile, but may merely be provided (e.g. inflate) so as establish an impedance barrier (e.g. a gas jacket) around a pile, and any water remaining between a located pile and the dampening structure.
According to a second aspect of the invention, there is provided guide apparatus for an offshore pile, the apparatus comprising a dampening structure or material.
The dampening material may be configured to provide a difference in acoustic impedance between the apparatus and surrounding water (e.g. an acoustic barrier). The dampening material may be provided as a coating, layer, or the like, which may be provided on the inner and/or outer of the apparatus (e.g. in the inner and/or outer of the guide portion). The dampening material may comprise a substrate having a plurality of gas-filled compartments or pockets. The dampening material may be configured as a coat (e.g. a wrapable coat for the guide apparatus, or portion).
The dampening material/structure may comprise a plurality of gas-fillable compartments, pockets or bladders. The bladders may be inflatable and deflatable. The guide portion may be configured with a plurality of bladders, spaced both circumferentially as well as lengthwise along the inside of the guide portion. The bladders may additionally comprise an outer friction sleeve, having an interface surface to allow reduced friction contact with a pile (e.g. comprising bristles, or the like).
The apparatus may comprise one or more dampening segments as the dampening structure. Each dampening segment may be configured to surround (e.g. fully surround) a pile, or the like. The dampening segments may be attached, joined or bonded together to provide the effective height of the apparatus (e.g. bonded together at a segment joints). The dampening segments may be considered to be discrete segments.
In some examples, the dampening segments may be configured to be coupled and decoupled to vary the effective height of the apparatus (e.g. couple together at a segment joints). The apparatus may be configured such that dampening segments can be added together and/or removed so as to vary an effective height of the apparatus.
Each of the segments (e.g. the apparatus) may be configured to be opened and closed and so as to surround a pile, or the like (e.g. opened and closed lengthwise so as to surround a pile). The segments may be fixable in the closed configuration (e.g. using fasteners, such as hook and hoop fasteners, zips, lacing, or the like). The segments may be fixable at an inner side and/or an outer side of the segment.
Each of the segments may be inflatable (e.g. gas inflatable). The segments, when inflated, may adopt a surrounding configuration. The segments, when inflated, may bias the dampening segment to the closed configuration. The segments, when inflated, may urge a length-wise opening of the segment/apparatus together so as to provide the closed configuration.
The, or each, segment may comprise a specific material, structure or fabric, having a particular orientation across the segment. The material may be permeable to fluid (e.g. air) and may be orientated radially to an axial centre line of the apparatus. The material may be considered to be a thread type fabric (e.g. a drop-stitch type fabric) orientated appropriately such that threads are provided radial to the centre line. The segment may be considered to have inner material or structure that acts perpendicularly to some or all the surface of the segment so as to provide a desired configuration of segment. This may also provide an essentially rigid surface, when inflated.
The segments, when deflated, may adopt (or be permitted to adopt) a stowable configuration (e.g. for storage on a vessel of the like). The segments, when deflated, may be stackable (e.g. adopt a substantially planar configuration so as to permit stacking one on top of the other).
Some or all of the dampening segments may be inflatable independent of other segments. For example, some or all of the segments may be permitted to be inflated to different pressures. Some or all of the dampening segments may comprise relief values, configured release pressure above a particular threshold (e.g. one or more pressure relief value).
Each segment may comprise a plurality of panels, which may be considered to be inflatable panels, configured to extend and surround a pile. Each segment may be configured in a substantially polygon configuration (e.g. box cross-section). In some examples, each section may comprise four panels.
Some or all of the segments may be of the same or similar effective height (e.g. 1 metre, 2 metres, 5 metres, 10 metres, or the like).
Some or all of the segments may have rigging sections, configured to attach the segment to support rigging. The rigging sections may be provided with webbing, extending from a segment.
The apparatus may comprise anchor points, provided at a lower section of at least one segment. The anchor points may be configured to couple the apparatus to a water floor (e.g. sea bed). The anchor points may permit the attachment of ballast weight, or the like (e.g. ballast configured to overcome any resultant or reactant uplift from an inflated series of segments).
The apparatus may comprise any of the features of the first aspect.
According to a third aspect of the invention there is provided guide apparatus for an offshore pile, the apparatus comprising a guide portion and a piling template.
The piling template may have two or more guide sockets for locating the guide portion with the piling template. The apparatus may be configured to allow for moving the guide portion between the sockets, so as to allow for positioning of two or more offshore piles.
The piling template may be configured to stabilise the guide portion, and/or may provide ballast for the guide portion.
The guide portion may be separable to allow a pile to be positioned within the guide portion. The guide portion may comprise an open configuration, and a closed configuration. The guide portion may be opened and closed, for example, along a lengthwise body axis (i.e. so as to allow the insertion of a pile from the side of the apparatus, rather than being lowered into the apparatus).
The guide portion may comprise two or more segmented portions (e.g. circumferentially segmented), at least one of which may be movable so as to open and close around a pile. The apparatus may comprise three segmented portions.
The guide portion may comprise a separable frame, configured to open to allow insertion and/or removal of a pile (or other driven structure) from the apparatus.
When in a closed configuration, the guide portion may surround a pile being deployed.
The apparatus may comprise any of the features of the first or second aspect.
According to a fourth aspect there is provided a method for providing, or deploying, a pile at an offshore site.
The method may comprise locating an offshore pile with a guide apparatus. The method may comprise providing an acoustic barrier between the pile and a body of water.
The method may comprise sealing the offshore pile with the guide apparatus. The method may comprise displacing water from a gap between the guide apparatus and the pile.
The method may comprise using a hammer to secure the pile into a water floor. The method may comprise unsealing the offshore pile with the guide apparatus. The method may comprise allowing the gap to fill with fluid. The method may comprise removing (e.g. lifting) the guide apparatus from a secured pile.
The locating of an offshore pile with a guide apparatus may including lowering the pile within the guide apparatus. The method may comprise centralising (e.g. concentrically) the pile with the apparatus.
The method may comprise (e.g. initially comprise) locating a guide portion of the apparatus with a piling template of the apparatus, then locating the offshore pile with the guide apparatus.
The method may comprise inflating a seal (e.g. an annular seal) in order to seal the pile. The method may comprise deflating a seal in order to unseal the pile (e.g. to allow for removal).
The apparatus may comprise a guide portion and a piling template. The piling template may comprise one or more guide sockets. Each guide socket may be configured to allow for location of a guide portion with the piling template. The guide sockets may be separated, such as radially separated, on the piling template.
The method may comprise moving the guide portion between one or more of the guide sockets. The method may comprise raising and lowering of the apparatus/guide portion. The method may comprise raising the guide portion, and moving the guide portion to be positioned above a further guide socket, and then lowering the guide portion. The method may comprise positioned the guide portion above a further guide socket when at least a portion of the guide portion in above water level.
According to a fifth aspect of the invention, there is provided a method of reducing the acoustic emissions during positioning of an offshore pile, comprising using guide apparatus comprising a dampening structure or material.
The dampening structure or material may be considered to be an acoustic barrier. The dampening material may be configured to provide a difference in acoustic impedance between the apparatus and surrounding water. The dampening material may be provided as a coating, layer, or the like, which may be provided on the inner and/or outer of the apparatus (e.g. in the inner and/or outer of the guide portion). The dampening material may comprise substrate having a plurality of gas-filled compartments or pockets. The dampening material may be configured as a coat (e.g. a wrapable coat for the guide apparatus, or portion).
The method may comprise opening the guide portion to allow location of pile within the apparatus, and then closing the guide portion around the pile. The method may comprise inflating a plurality of bladders, which may be spaced both circumferentially and/or lengthwise along the inside of the guide portion.
The method may comprise using one or more dampening segments as the dampening structure. Each dampening segment may be configured to surround (e.g. fully surround) a pile, or the like.
The method may comprise providing a first dampening segment to surround a pile, or the like, and then adding (e.g. bonding) a second dampening segment to the first dampening segment so as to increase the effective height of the dampening structure. The method may comprise removing dampening segments (e.g. after a pile has been located).
The method may comprise coupling and decoupling dampening segments so as to vary the effective height of the apparatus (e.g. couple together at a segment joints).
The method may comprise opening and closing each dampening segment and surrounding a pile, or the like with the dampening segments (e.g. opening and closing lengthwise so as to surround a pile). The method may comprise fixing the segments in the closed configuration (e.g. using fasteners, such as hook and hoop fasteners, zips, lacing, or the like). The method may comprise fixing the segments at an inner side and/or an outer side.
The method may comprise inflating (e.g. inflating with air) each segment. The method may comprise inflating each segment with air and cause the segment to adopt a surrounding configuration. The segments, when inflated, may bias the dampening segment to the closed configuration. The segments, when inflated, may urge a length-wise opening of the segment together so as to provide the closed configuration.
The segments, when deflated, may adopt (or be permitted to adopt) a stowable configuration (e.g. for storage on a vessel of the like). The segments, when deflated, may be stackable (e.g. adopt a substantially planar configuration so as to permit stacking one on top of the other). The method may comprise deflating each segment, and stowing the segment.
The method may comprise inflating each segment to different pressures (e.g. depending on depth). Some or all of the dampening segments may comprise relief values, configured release pressure above a particular threshold (e.g. one or more pressure relief value).
The method may comprise considering the intended water depth, and then bonding a plurality of a segments together to provide an appropriate effective height of apparatus. Some or all of the bonded segments may be of the same or similar effective height (e.g. 1 metre, 2 metres, 5 metres, 10 metres, or the like).
The method may comprise attaching an anchor point of a lower section of a first segment to a water floor, or to a ballast weight, and coupling subsequent segments to the first segment.
According to a sixth aspect of the invention there is provided a method for positioning two or more offshore piles, the method comprising
According to a seventh aspect of the invention there is provided guide apparatus for an offshore pile, the apparatus comprising:
According to an eighth aspect of the invention there is provided a method for providing a pile at an offshore site, the method comprising:
According to a ninth aspect of the invention there is provided apparatus for positioning an offshore pile, the apparatus comprising a guide sleeve or portion configured to receive a pile, and configured, in use, to provide a gas gap between the guide sleeve or portion and a received pile.
The air gap may be provided by using at least one seal, to seal the sleeve to the pile. The gas gap may be provided using at least one pump (e.g. to displace fluid from the gap). The gas may be air.
According to a tenth aspect of the invention there is provided method for positioning an offshore pile, the method comprising:
The method may comprise displacing water from the gap to provide the gas gap. The method may comprise pumping water from the gap to provide a gas gap (e.g. an air gap).
According to an eleventh aspect of the invention there is provided method for positioning an offshore pile, the method comprising:
The method may comprise providing the guide sleeve or portion with dampening material, such that closing the guide sleeve or portion surround or partially surrounds the pile with a dampening structure or material.
The method may comprise inflating a plurality of bladders, which may be spaced both circumferentially and/or lengthwise along the inside of the guide portion. The method may comprise any of the features of any of the above referred-to aspects.
The above summary is intended to be merely exemplary and non-limiting. The invention includes one or more corresponding aspects, embodiments or features in isolation or in various combinations whether or not specifically stated (including claimed) in that combination or in isolation.
For example, any features of the first aspect may equally be features of fourth, fifth, sixth, seventh or ninth aspects, etc., without the need to unnecessarily and list those various embodiments or features.
It will be appreciated that one or more embodiments/aspects may be useful when providing piles, or other such structures, at one or more offshore site(s), which may include installing wind turbine structures at an offshore site, or other offshore structures. Corresponding means for performing one or more of the discussed functions are also within the present disclosure.
A description is now given, by way of example only, with reference to the accompanying drawings, which are:—
a shows a perspective view of exemplary guide apparatus, and an offshore pile, and
a and 4b show an exemplary seal;
a, 5b and 5c further show the apparatus of
a, 6b and 6c show a further example of guide apparatus;
a, 7b and 7c show an example of stabilisers of the apparatus of
a and 17 show an example of the apparatus of
a shows a perspective view of guide apparatus 100, which in this example can be considered to be guide apparatus for positioning/deploying an offshore pile 200.
The apparatus comprises a guide portion 110 and a piling template 120. In use, the piling template 120 is configured to be positioned on a water floor 300 (e.g. seabed, or the like). In this example, the guide portion 110 is configured essentially as a sleeve, through which the pile 200 can be positioned.
Here, the piling template 120 comprises four guide sockets 125. Each guide socket 125 is specifically configured to allow for location of the guide portion 110 with the piling template 120. The guide portion 110 is configured to locate, and be positioned with, the template 120 (or the socket 125 thereof) to allow for guiding of the pile 200 to the water floor 300.
The apparatus 100 is configured to allow for movement (e.g. both rotational movement and vertical movement) of the guide portion 110 so as to allow it to be moved between two of more of the guide sockets 125. In this example, the guide portion 110 can be moved relative the sockets 125 by means of a central pillar 130a and collar 130b. The piling template 120 further comprises stabilisers 140 (in this example, four stabilisers), to stabilise and/or orientate the apparatus 100 with a water floor 300.
The guide apparatus 100 further comprises a guide cone 145 on an upper region thereof. The guide cone 145 is configured to allow for the pile 200 to be lowered and located with the apparatus 100. For example, the cone 145 can assist in locating the pile within the sleeve as it can urge a pile 200 being deployed from a vessel into alignment with the sleeve.
In this particular example, and as is shown in
To allow the pile 200 to be located within the apparatus (e.g. centrally within, such as concentrically within, the guide portion 110), in this particular example the apparatus 100 also comprises arms 150 at the guide portion 110. The arms 150 are configured to hold, and/or guide, the pile 200 in a particular orientation within the guide portion 110. In this example, the arms 150 are positioned at upper and middle regions of the guide portion 110. Here, the arms 150 are configured to be adjustable, and extend and/or retract (e.g. hydraulically) in order to hold/guide the pile 200. Also, in this example, the arms 150 are configured to acoustically decouple the pile 200 from the guide sleeve 110. In other similar words, the arms 150 are configured to mitigate any acoustic transmission between the pile 200 and the apparatus 100. This may be achieved by providing an appropriate impedance mismatch between the arms 150 and the pile 200 and/or guide portion 110.
While, in this example, arms 150 have been used, it will be appreciated that further apparatus, mechanisms, or features may be used to hold/guide the pile 200 within the apparatus. For example, in some cases, guide vanes located on the inner of the guide portion 110 may be used. Such guide vanes may be tapered to allow for a smooth location of the pile 200 in the guide portion 110. Further radial members, such as one or more radially extending cones each having an aperture, may be used.
The apparatus may comprise any combination of arms, vanes or radial members (some or all of which may be configured to mitigate any acoustic transmission between the pile 200 and the apparatus 100) or, even, in some cases, none of these features. Furthermore, any of the arms, vanes or radial members may be provided with the apparatus 100 and/or the pile 200, as will be appreciated.
a and 2b show an example of the apparatus 100 is use. Here, the guide portion 110 has been located with a particular socket 125. The pile 200, which is to be driven into the water floor 300 (e.g. seabed) by means of a hammer 400, has been lowered and located with the apparatus 100. As can be seen, fluid, and in this example water 500 fills a gap 600 between the pile 200 and guide portion 110 of the apparatus 100. In this example, due to the tubular or cylindrical construction of the pile 200 and the guide portion 110, the gap 600 is essentially annular. However, differing configurations may provide differing gaps 600. In addition, water may fill the inner of the pile 200.
In this example, the apparatus 100 comprises at least one pump 160 configured to displace fluid from the gap 600 (e.g. the annular gap 600). Here, the pump is configured to displace water to from the gap to the body of water surrounding the apparatus. The apparatus further comprises at least one seal 170 configured to seal the guide apparatus 100 with the pile 200. The seal 170 is configured to prevent fluid entering the gap 600 (e.g. from a body of water to the gap). In this example, both the seal and the pump are provided at a lower region of the guide portion 100. The pump 160, in this example, is positioned, relatively speaking, above the seal 170. In this particular example, the seal is further configured to acoustically decouple the pile 200 from the guide portion 110, in a similar manner to the arms described above. In other similar words, the seal is additionally configured to mitigate any acoustic transmission from the pile 200.
Due to the configuration of the gap 600, the seal in this example is annular (e.g. a tyre type seal). The seal(s) can be inflated and deflated to allow for sealing the apparatus with the pile 200. Here, the seal 170 is configured such that sealing is effected, but that the pile is still permitted to translate within the guide portion. A lesser radial force is required to seal the pile 200, than to seal and grip fixedly the pile 200. Therefore, sealing can be effected without restricting the, in this case, vertical movement of the pile 200.
In use, after the pile 200 has been located with the apparatus 100, the arms 150 can be actuated in order to position the pile 200 appropriately within the guide portion 110. The seal can be actuated to seal the pile 200 with the guide apparatus 100. The pump can be operated to displace water 500 from a gap 600 between the guide portion 110 and the pile 200, such that there is an acoustic barrier (in this example a gas gap) between the guide portion 110 and the pile 200. In this case, due to guide portion being above the water level, air is permitted to fill the gap 600. Of course, in further embodiments, the gap between the pile and the apparatus 100 (in this example guide portion 110) may be filled with gas by different means, which may not be air (e.g. nitrogen). For example, the apparatus 100 may comprise a seal 170 at an upper region of the guide portion 110, such that gas can be communicated to the annular gap so as to force water from the gap, for example, at a lower region or aperture. In some cases, only an upper seal may be provided.
Irrespective, subsequently the hammer 400 can be used to secure the pile 200 into a water floor. Due to the sealing nature of the seal, which allows movement of the pile 200, the seal is not affected by the hammering of the pile into the water floor 300, and the dewatering is maintained. In some case, when not using an upper seal, water may enter the gap from above (e.g. from splashing or the like) and/or partially thought the seal (when used). In those circumstances, the pump 160 may maintain operation in order to continue to dewater the gap 600.
Due to the gas gap (and in essence the impedance decoupling between the pile 200 and the water 500), which may be an air gap or gas from a gas source, such as compressed gas, any acoustic emission from the pile 200 to the water (e.g. the sea) is attenuated or reflected within the pile 200. In other words, the gas gap serves to prevent, or reduce, the chance that harmful (and powerful) acoustic emissions associated with the driving of the pile are communicated (or communicated to a harmful extent) to the surrounding water. As such, acoustic emissions to surrounding water that is associated with positioning (and hammering) such piles can be reduced or essentially avoided altogether.
Subsequent to the positioning of the pile 200, the seal 170 can be unsealed (e.g. deflated). The guide portion 110 can be removed before or after the seal 170 has been deactivated. If the gap 600 is allowed to fill with water, then this may assist with removing (e.g. lifting) the guide portion 110 from a secured pile 200.
After one pile has been deployed and positioned, the guide portion can be moved to a subsequent socket. In such a way, and irrespective of the use of the acoustic barrier or the like, the guide portion/piling template need only be deployed once in the water, yet is able to be used to deploy and position several different piles. As such, the time taken to accurately position many piles can be reduced. Further, the cost of apparatus for deploying many piles can be minimised.
In some examples, as is shown in
Irrespective of the use of the gas gap, or piling template, etc. providing the dampening material with the guide apparatus, rather than the pile, obviates the need to repeatedly coat each pile 200. Of course, in alternative examples, the pile 200 may be provided additionally of alternatively with a dampening material 800.
In such examples, providing the piling template may help ballast, or weigh down, the guide sleeve to counteract any uplift associated with the buoyancy of the dampening structure/material. Providing ballast weight to the piling template, or support structure, rather than the guide portion can assist with ease of movement of the guide portion (e.g. between sockets).
a and 4b shows a cross section of an example of a further exemplary seal 270 in operation, which by way of example is shown with a pump 160 and is shown at a lower region of the guide portion 110. In
a shows the gap 600 filed with water 500. In
After a pile 200 has been positioned at a particular location, the guide portion 110 may be raised and associated with a further guide socket, by moving the guide portion 100 between the sockets 125, so as to allow for positioning of two or more offshore piles 200, as exemplified in
While the above described examples show a guide portion 110 in use with a piling template, it will be appreciated that in further examples, that piling template need not be used. For example, in some embodiments of the guide apparatus 100, only a guide portion 110 may be used. In those examples, the guide portion 110 may be located on the seabed, or the like, and the seal activated in the manner described above, to allow for positioning of a pile 200. Similarly, it will be appreciated that any number of seals and/or pumps may be used. For example, the guide portion 110 may be compartmentalised by respective seals and pumps to allow for positioning of a pile 200. Additionally, further means for providing an acoustic barrier or gas gap (e.g. an air gap) between the guide portion and the pile are envisaged, and within the scope of the invention.
a, 6b and 6c show a further example of guide apparatus 1000 for use in deploying or locating offshore structures, such as piles, or the like, which may be used to support offshore wind turbine towers.
The guide apparatus 1000 again comprises a guide portion 1100, and piling template 1200, together with guide sockets 1250 (three of which are given in this alternative example) in a similar manner to that described above. It will be appreciated that the use of sockets may be useful in some cases to allow alignment of the pile with a particular intended location from deployment. However, in other examples, the apparatus 1000 may not comprise such sockets, or the like.
Again, the guide portion 1100 is configured to locate, and be positioned with, the template 1200 (or the socket 1250 thereof) to allow for guiding of a pile 200 to the water floor 300, such as the seabed. Similarly, the apparatus 1000 allows for movement of the guide portion 1100 so as to allow it to be moved between two of more of the guide sockets 1250.
Additionally, and although not essential, the piling template 1200 here comprises stabilisers 1400 (three shown in
a, 7b and 7c show the stabilisers 1400 in the deployed configuration, in which they have been rotatably moved from their stowed configuration. Providing a stowed configuration may permit ease of transport to/from an offshore site, for example, ease of stacking on a deck. In addition, providing a stowed configuration may permit the apparatus to be readily lowered to the water floor.
Each stabiliser 1400 is configured to be able to be locked, or retained, in the deployed configuration. Here, support struts 1410 extend from each stabiliser 1400 to a support frame 1420 of the piling template 1200 so as to lock that stabiliser 1400 in the deployed configuration.
Here, the sockets 1250 and guide portion 1100 are able to be moved relative to the stabilisers 1400 so that they can be more suitably vertically aligned (e.g. in cases of an uneven seabed). In other words, the sockets 1250 and guide portion 1100 are able to be moved so as to avoid unwanted inclination of a pile 200. It will be appreciated that such a configuration can assist with deployment of piles, where vertical, or plum, alignment may be desired.
In this case, a main frame 1430 of the apparatus 100, which connects the guide portion 1100 and sockets 1250, is configured to be moveable with respect to the stabilisers 1400. In this example, this is achieved using a gimbling system 1600 (e.g. using controllable hydraulic cylinders, etc. as shown on
Unlike the example given in relation to
The guide portion 1100 opens and closes along a lengthwise body axis 1700 so as to allow the insertion of a pile 200 from the side of the apparatus 1000 (i.e. rather than only being lowered into the apparatus 200). Here, the guide portion 1100 is circumferentially segmented into three portions 1100a, 1100b, 1100c at least two of are movable so as to open and close around a pile 200—see
When using the guide apparatus 1000 of
Permitting the pile 200 to be initially lowered into the body of water, rather than into the guide portion, allows for the body of water to dampen movement of the pile 200 as it is positioned with the apparatus 1000. In other words, the water may inhibit swinging, swaying, etc. of the pile 200 during location of the pile 200 with the apparatus 1000. Such a configuration may be useful when deploying a pile from a vessel subject to marginal or adverse weather conditions, irrespective of whether or not the guide portion 1100 or apparatus is additionally configured to mitigate acoustic emissions
To assist further with deployment, the apparatus 1000 is configured to retain (and in some cases seal) the guide portion 1100 with respect to sockets 1250.
In some examples, the guide apparatus 1000 is configured to dewater the guide portion 1100 in a similar manner to that described above, and so displace water 500 from a gap 600 between the guide portion 110 and the pile 200. In such a manner, an acoustic barrier provided as a gas gap may be obtained between the guide portion 110 and the pile 200 to mitigate the transmission of acoustic emissions.
However, in alternative examples (and as is shown here) the guide portion 1100 may comprise an acoustic dampening structure 1800 (e.g. material) at least an inner surface thereof (e.g. dampening material configured to an acoustic barrier by providing a difference in acoustic impedance between the apparatus (e.g. the guide portion 1100) and a located pile 200, with or without the use a pump/seal.
In some such cases, when the guide portion 1100 is closed around a pile 200, the dampening structure 1800 can attenuate acoustic transmission from the pile 200 to the body of water during hammering of the pile 200 into the seabed. In some examples, the guide portion 1100 may be configured such that the dampening structure 1800 abuts against the pile 200 when located within the guide 1100. In other words, after closing the guide portion 1100, the dampening structure 1800 may interface against a located pile 200. As such, the process of closing the guide portion 1100 may be considered to be urging water from the inner annular of the guide portion 1100. In such a way, the acoustic attenuation may be improved further.
In addition, in some examples in which the guide portion 1100 abuts against the pile, when located, then the weight (and lack of buoyancy) of the pile may be used to assist with lowering of the guide portion together with the pile into position (e.g. onto a socket).
It will be appreciated that in examples in which the dampening structure 1800 abuts against the pile 200, then an intended interface surface 1850 of the structure 1800 may be configured for reduced friction (e.g. using bristles on the interface surface 1850, or a lubricious material, such a PTFE, or the like). In such a manner, the dampening structure 1800 may contact the pile 200, yet not overly inhibit vertical movement of the pile 200 during hammering.
In some examples, the dampening structure may comprise gas-filled pockets, or the like, or closed-cell foam, or the like. In some cases, such dampening structures 1800 may be compressible against the pile 200 in order to couple to the pile 200, as well as remove any water from around the pile 200.
In the example described here, and as is shown in more detail in
Here, the guide portion 1100 is configured with the plurality of bladders 2000, which are spaced both circumferentially as well as lengthwise along the inside of the guide portion 1100. In this example, and as is shown in
a shows one axial length of bladders 2000 that depend along some or all of the length of the guide portion 1100, whereas
In use, after a pile 200 has been located within the guide portion 1100, the guide portion 1100 can close around the pile 220 (e.g. in order to retain the pile 200). Subsequently, each of the bladders 2000 can be inflated so as to couple with the pile 200, and effectively urge water from the inner of the guide portion. As the bladders are gas filled, an effective acoustic barrier (e.g. gas gap) is provided and acoustic transmission from the pile to the body of water is inhibited. It will be appreciated that in the example of using bladders 2000, or the like, then coupling the guide portion 1100 with a socket (e.g. using a lip and groove, as shown in
In some examples, each, some, or all of the bladders are operable independently, or at least in groups. In other words, the volume of each, some or all of the bladders may be controllable. This may assist with locating and centralising of a pile position with the guide portion.
It will further be appreciated that in some cases the bladders 2000 (or other suitable dampening structure 1800) need not couple to a located pile 200, i.e. touch, but may merely be provided (e.g. inflate) so as establish an acoustic barrier, or gas jacket, around the pile, with water remaining between the pile 200 and the dampening structure 1800. In some of those examples, the guide portion may be comprise arms, or the like, similar to those described in relation to
In any event, as before, due to the effective impedance decoupling between the pile 200 and the water 500, any acoustic emission from the pile 200 to the water (e.g. the sea) is attenuated or reflected within the guide portion 1100. In other words, the dampening structure 1800 serves to prevent, or reduce, the chance that harmful (and powerful) acoustic emissions associated with the driving of the pile 200 are communicated (or communicated to a harmful extent) to the surrounding water. As before, acoustic emissions associated with positioning (and hammering) piles can be reduced or essentially avoided altogether.
After fixing of a pile to a water floor, some or all of the bladders can be deflated, and retracted, to avoid damage as the guide portion 1100 is removed from the positioned pile.
Further examples of providing an acoustic barrier comprise configuring the apparatus 100, 1000 so as to inject gas, or gas bubbles, within the annulus of the guide portion (e.g. so as to provide a bubble jacket between a pile 200 and the guide portion, or between the dampening structure and a pile). The bubbles or gas may be injected at a single region (e.g. the lower region of the guide portion), or may be injected at different regions, circumferentially and/or axially. Compressed air may be used. In some cases, the apparatus is configured such that gas bubbles, being provided within the guide portion, are adhered or retained to or with a friction surface (e.g. between the bristles of the outer friction surface). These friction surfaces, configured to trap or retain gas bubbles, may or may not be used with additional dampening material (e.g. the bladders).
In such a manner, alternative or additional acoustic barriers can be provided within the guide portion. A skilled reader will readily be able to implement such further embodiments.
While providing a dampening structure or material on the inner side of the separable guide portion may mitigate that chances of that structure/material being subject to damage (e.g. from objects striking the apparatus), nevertheless, in some further examples, the dampening material/structure, or other such acoustic barrier, may be provided additionally or alternatively on the outer side of the guide portion.
It will also readily be appreciated that while some of the above examples of the guide apparatus 100, 1000 have been illustrated with use of a piling template 120, 1200, or the like, in further examples the guide apparatus 100, 1100 may comprise one or more guide portions 110, 1100 without the use of a piling template 120, 1200, per se. Such guide portions, or sleeves, may be used in isolation (e.g. manoeuvred and surrounding a monopile, or the like), or may be used in conjunction with further apparatus. Similarly, in some examples the piling template may be used without the use of a guide portion. Such embodiments will be evident given the above detailed description.
In addition, while in the above described examples, the dampening structure is described as being inflatable, it will readily be appreciated that in some examples the pockets, or the like, may be permanently gas filled (e.g. closed-cell foam, or the like).
Here, each dampening segment 3010 is configured to surround (e.g. fully surround) a pile, or the like (not shown for clarity). The apparatus 3000 is configured such that multiple dampening segments 3010 are attached so as to provide an effective height, H, of the apparatus 3000. In this particular example, each segment 3010 is 5 metres in height and so, when attached (e.g. bonded together) at a segment joint 3020, the effective height, H, of the apparatus 3000 can be considered to be 10 meters. Of course, in further example, the segments may be of a different height (e.g. 1 metre, 2 metres, etc.).
Although bonded in this example, in some alternative cases the segments 3010 may be coupled together so that segments can be readily added together and/or removed so as to vary the effective height of the apparatus 3000. In such cases, fasteners, such as loop and hook fasteners, zips, or the like may be used. In these cases, piles can be deployed in different water depths without the need for specific apparatus 3000.
In the example given, when locating a pile in water depth of around 9 metres, then two dampening segments 3010 may be used, whereas if a pile then needs to be located in water depth of around 13 metres, then a further segment 3010 may be attached (or bonded) to the first two segments so as to accommodate the change in water depth. Of course, in some examples, the apparatus 3000 can have different segment lengths (e.g. 2×5 meters and 1×2 meters=12 meters effective length). In some cases, as will later be described, the dampening material may be inflatable, and it may be that when deploying in different depths different segments are inflated depending on the depth. In other words, not all of the segments may be inflated.
It will be appreciated that such a modular configuration may be useful so as to avoid having to choose individually appropriate piles, supports, equipment and other tools for each site, and can readily accommodate the different ambient pressure at different depths of water.
In the example shown, the segments 3010 comprise a plurality of panels 3030 that extend around a pile, or the like. In this example, each segment 3010 has four such panels 3030 and so provides essentially a box cross-section, having an outer surface and an inner surface. Of course, in further examples, different numbers of panels 3030 may be provided.
In some examples, one, some or all of the segments 3010 may be configured to be opened and closed and so as to surround a pile, or the like (e.g. opened and closed lengthwise so as to surround a pile), in a similar manner to that described above.
As can be seen, the interface at the opening is specifically configured to such that any water pathway across the opening in minimised. In other words, the opening is configured so that, when closed, the segment nevertheless provides a barrier around the pile (i.e. substantially without having a gap).
While the above segments 3010 may comprise dampening material (e.g. deformable foam, or the like), in other examples, the segments 3010 can be inflatable (e.g. inflatable using compressed air). In those cases, the segments 3010 can be specifically configured such that, when inflated, they adopt the surrounding configuration (e.g. the box cross-section).
The segment can therefore be considered to have inner material 3075 or structure that acts perpendicularly to some or all the surface of the segment 3010 so as to provide a desired configuration of segment 3010, as well as an essentially rigid surface, when inflated.
When deflated, the segment 3010 can also adopt (or be permitted to adopt) a stowable configuration (e.g. for storage on a vessel of the like). In some cases, the deflated segment 3010 can adopt a substantially planar configuration, as is shown in
In examples in which the segments 3010 are openable and closable then the segment may be configured such that, when inflated, the segment 3010 is bias to adopt the closed configuration. In other words, the segments 3010, when inflated, can urge the length-wise opening of the segment 3010 together so as to provide the closed configuration. In some examples, and as is shown in
To assist with deployment of the apparatus 3000, in some example the apparatus 3000 may comprise anchor points 3100, as shown in
In further examples, the apparatus 3000 may comprise rigging sections 3110, configured to attach each segment 3010 to a support rigging 3120, as is shown in
In use, multiple segments 3010 can be inflated and deployed around a pile (e.g. open and closed) depending on the desired depth. The pressure of each dampening segment 3010 may be provided independent of other segments 3010. For example, the segments 3010 may be configured to be pressurised to roughly 0.6 bar above ambient pressure for the intended depth of that segment. In some cases, the some or all of the dampening segments 3010 may comprise relief values 3200, as shown in
After the pile has been located, the apparatus can be removed and deflated and readily stacked for further use.
It will be appreciated that the above described apparatus 3000 may additionally be used with the piling template shown, for example in
Although not described in detail, it will readily be appreciated that the apparatus 1000, 3000 of any of the
While in this specification the term, “offshore”, has been referred to, it will be understood that this term is not to be considered to be limited to at sea, but rather offshore can refer to any region or expanse of water, such as, seas, lochs, lakes, forths, estuaries, etc. Some examples of the apparatus may be useful in water depth of at least 40, 50, 60 metres or even greater. Further, while it has been helpful to describe the above exemplary embodiments in relation to installing supporting piles, or like, for wind turbine assemblies, it will readily be appreciated that the invention is also useable when constructing other structures offshore, including bridges, harbours, coastal walks, oil and gas structures, or the like. In those cases, the above apparatus may be used for securing piles, or other apparatus that are not piles, as such, but nevertheless are secured to a seabed or the like using a hammer, or other such device that would cause unwanted acoustic emissions. A skilled reader will readily be able to implement those alternative embodiments.
The applicant discloses in isolation each individual feature described herein and any combination of two or more such features, to the extent that such features or combinations are capable of being carried out based on the specification as a whole in the light of the common general knowledge of a person skilled in the art, irrespective of whether such features or combinations of features solve any problems disclosed herein, and without limitation to the scope of the claims. The applicant indicates that aspects of the invention may consist of any such individual feature or combination of features. In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1205543.0 | Mar 2012 | GB | national |
| 1217367.0 | Sep 2012 | GB | national |
| 1221241.1 | Nov 2012 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB2013/050870 | 4/2/2013 | WO | 00 |
