CN1119259C

CN1119259C - Ship for offshore operations with vertical openings

Info

Publication number: CN1119259C
Application number: CN99804596A
Authority: CN
Inventors: K·赛弗森; A·斯梅达尔
Original assignee: Hitec AS
Current assignee: Hitec AS
Priority date: 1998-02-05
Filing date: 1999-02-03
Publication date: 2003-08-27
Anticipated expiration: 2019-02-03
Also published as: NO980498D0; ES2211054T3; DE69912244T2; RU2243128C2; PL342664A1; AU2862599A; NO980498L; NO308348B1; PT1053171E; EP1053171A1; AU747520B2; BR9910888A; CA2319487A1; KR20010040670A; CN1295523A; DE69912244D1; EP1053171B1; WO1999039971A1; JP2002502761A

Abstract

A ship for use in offshore operations, with one or more vertical openings (moonpools) in the hull, wherein the deck and/or hull bottom areas between or substantially between and/or otherwise adjacent the openings, are displaced relative to the rest of the deck and/or hull bottom areas of the ship to a position closer to the ship's transverse neutral axis. The area between the rest ot the other deck- and hull bottom areas and substantially the displaced area or areas is gradually stepped. Alternatively, the area between the displaced deck- and/or hull bottom area or areas at the openings in the ship and the rest of the deck- and/or hull bottom areas can be stepped in one or more steps, or be shaped as an approximately linear or arcuate junction.

Description

The ship that marine operation is used

The present invention relates to the ship that the confession marine operation is used, this ship has one or more vertical openings on hull, so-called moonpool.Now, the opening that for example is used as on the hull of drilling vessel is very common, and their occur separately and respectively, and are used for various operations.Require in some cases the good equipment of fixed installation to be set so that carry out specific operation approaching such moonpool place.This can be derrick crane for example, and one is used for putting into such as ROV (remote-operated vehicle) jacking equipment marine and that propose, or is used for being undertaken by the opening on these hulls other equipment of operation.

Disclosed among the U.S. Pat 4281716A and a kind ofly in a well of from one group of submarine well, selecting, carried out method of operating, by production jacking equipment building equipment on a floating platform.Be provided with a workover jacking system flexibly on platform, the passage that it runs through on this platform a position away from the moonpool of producing jacking equipment extends.This workover bont is by the operation of described passage, and is directed to production pipeline in the submarine well and is connected.Can carry out pipeline or other well operations by this workover bont that connects from floating platform.

Usually all openings can be had various cross sectional shapes and size along the longitudinal centerline setting of ship and its, but they usually are rectangle or approximate rectangular, if there is several openings, then they then ground are provided with and it can have same cross sectional shape and size along one of the longitudinal centerline of ship.If all openings are not to be used for specific operation, then they can be built in the inside of ship so that the navigation of ship is had influence.

When stress that ship suffers to be caused by wave or other loads, the opening of rectangle has influence to the distribution of stress in especially deck and the hull base plate.In some zone, the recess of stress concentration may appear producing, and here stress level can be higher than the steady component of stress in deck or the hull base plate widely.Particularly each corner at rectangular aperture will produce stress concentration, also be like this even these corners are designed to reduce as far as possible the recess effect.Also might alleviate this situation, but stress concentration factor will usually be very big, and stress concentration factor is 2 to be by no means rare by suitably designing supporting plate and local reinforcement.

When designing and building a drilling vessel, such stress raisers will be necessary to consider, and the particularly basis of the fatigue life of ship is calculated in their formation.Under some operating mode, such as the long-term operation of (North Sea) in the North Sea, fatigue may be to determine a decisive criterion of the cross sectional dimensions commonly used of a drilling vessel.In fact, the size that this means deck and hull base plate must be increased widely to satisfy the requirement of its anti-fatigue ability.Except production process more the complexity, this also will be referred to remarkable higher cost.And, when for example derrick crane that uses by the hull opening is fixedly installed to areal of stress concentration or near such when regional, load condition and distribution of stress will be more complicated and variable.When determining the position of this class fixed equipment, advantageously stress and stress concentration should be minimum and not have stress raisers, or have potentiality in these areas as far as possible uniformly.This can also form simpler structure in the manufacturing, and it will help to reduce the manufacturing cost related with ship again.

General opinion about distribution of stress in deck and the hull base plate is, when stress that ship suffers to be caused by wave and other loads, the stress in deck and the hull base plate will the approximately linear ground increase with the distance of the horizontal neutral axis of distance ship.In other words, deck and the hull base plate that is arranged on apart from the horizontal neutral axis farthest of ship will have the highest stress level.And because the structure of deck and hull base plate, as long as include the part that produces the recess effect in such structure, stress will be strengthened at the stress raisers place.These parts can be equipment of sharp-pointed corner, opening, welding etc.Therefore, based on these factors, two kinds of terms of settlement that are used to reduce stress concentration are obviously arranged, the first reduces the recess effect in deck and the hull base plate, and another terms of settlement is devoted to determine that the present invention is as target in the deck of (for example being rectangle) opening and hull base plate position and the structure thereof with respect to the horizontal neutral axis of ship.

According to the present invention, the ship that provides a kind of marine operation to use, in its hull, have one or more openings that run through fully or partly run through, wherein, be in or be in basically between the described opening and/or described opening near deck and/or territory, hull base area be displaced to apart from the nearer position of the horizontal neutral axis of ship with respect to remaining boat deck and/or territory, hull base area.

If the deck and the hull base plate with opening of using for moonpool of ship are arranged on the position of more approaching horizontal neutral axis, then the steady component of stress level will be lower, and will be less by the stress concentration that recess causes.This will be again in the size of determining deck and hull base plate, particularly a main foundation when determining size aspect minor load and fatigue life.In having the drilling vessel of moonpool, comprise as the application, will always there be problem of stress concentration at the position of port that passes deck and hull base plate or so-called moonpool owing to recess.By with these decks and hull base plate or optionally only with deck or hull base plate to the horizontal neutral axis direction displacement of ship, will obtain lower steady component of stress level.This will produce less peak stress, thereby help to reduce the requirement to thickness of slab, and it causes the expense of ship lower again.

In the structure of being advised, on the deck at moonpool edge (on upper deck) thereby and base plate will be continuous and without any causing recess and causing the opening of stress concentration.

The present invention illustrates in detail now with reference to the following drawings:

Fig. 1 is that wherein deck between each moonpool and hull base plate are shifted according to the present invention by the side sectional view of the hull with three moonpools of the line of centers intercepting of ship;

Fig. 2 is by the side sectional view of the ship with a moonpool of the line of centers intercepting of ship, wherein is shifted according to one embodiment of the invention at the rear of moonpool and the deck and the hull base plate in the place ahead;

Fig. 3 is that its tween deck and hull base plate are shifted according to one embodiment of the invention by the side sectional view of the ship with a moonpool of line of centers intercepting;

Fig. 4 is the top view of hull shown in Figure 1;

Fig. 5 is the top view of hull shown in Figure 2;

Fig. 6 is the top view of hull shown in Figure 3;

Fig. 7 is that its tween deck and hull base plate are provided with according to the present invention at the cross sectional drawing of the moonpool center of the ship with a Double bottom and double-deck;

Fig. 8 is that its tween deck and hull base plate are provided with according to the present invention at the ship of the ship with a Double bottom and double-deck and the cross sectional drawing of center;

Fig. 9 is that its tween deck and hull base plate are provided with according to the present invention at the cross sectional drawing of the moonpool center of the ship with a single end and single deck; And

Figure 10 is for having a Double bottom but the cross sectional drawing of the moonpool center of the ship of non-double-deck.The deck at moonpool place is shifted according to the present invention.

One embodiment of the invention are shown among Fig. 1 with the side sectional view that the line of centers by hull intercepts, and this hull has three vertical openings that run through of then locating along the longitudinal direction, also is commonly referred to as moonpool.According to the present invention, deck district 8 between each opening 2 and hull base section 4 are shifted by this way, that is: deck 8 is shifted by downward horizontal neutral axis 20 directions to ship, and similarly, hull base plate 4 is with respect to the horizontal neutral axis 20 directions displacement of remaining hull base plate to ship.This can be found out that also the there illustrates and same structure shown in Figure 1 with top view by Fig. 4, and wherein each opening or moonpool 2 have deck district 8 therebetween along the line of centers location of ship.Deck district 8 shown in the shade line thereby be moved to the lower zone of steady component of stress level, and because such location such as will reduce in the corner at the influence of the recess effect located.

Fig. 2 is the side sectional view by the hull with a moonpool 2 of line of centers intercepting.The deck of the every side of moonpool is distinguished into zone 9 and 10.They are all with respect to the horizontal neutral axis 20 directions displacement of remaining deck to ship.And, hull base plate 5 and 6 also in the vertical direction towards horizontal neutral axis 20 displacement of ship.As the displacement in zone 4,8 among Fig. 1, this causes lower steady component of stress level in deck and hull base plate.Different being among technical scheme among Fig. 2 and Fig. 1 all is shifted at the front edge of moonpool 2 and the deck and the hull base section of rear edge in this case, and only is that zone between each moonpool is shifted in Fig. 1.Except these two kinds of technical schemes, the combination of these two kinds of technical schemes is possible in having more than the ship of a moonpool, wherein deck between each moonpool and territory, hull base area can also can be shifted to horizontal neutral axis 20 directions of ship at the front edge of row's moonpool and the deck and the territory, hull base area of rear edge simultaneously to the horizontal neutral axis 20 directions displacement of ship.Technical scheme among Fig. 2 also is shown among Fig. 5 with the form of top view, and the

deck district

9 and 10 that wherein is shown clearly in the front and rear of moonpool 2 only covers the part in zone,

boat deck.Deck

9 and 10 displacement and hull base plate 5 and 6 displacement all progressively the segmentation setting so that make deck 9 and hull base plate 5 and deck 10 compare in the vertical direction with hull base plate 6 more to the horizontal neutral axis 20 directions displacement of ship.This is in order further to reduce the recess effect, thereby, to shift to the zone of lower steady component of stress level except making deck district and territory, hull base area, this helps to reduce the stress concentration in their structures again.

Another alternative embodiment is disclosed among Fig. 3, and this illustrates the side sectional view by the hull with a moonpool 2 of line of centers intercepting, and is shifted at deck district 11a and 11b place according to the present invention at the rear side of moonpool and the deck district at place, front side.And, be shifted at

hull base plate

7a and 7b place in the front side of moonpool 2 and the hull base section at rear side place.Different with the technical scheme disclosed in Fig. 2, represent by a near linear plane inclined 7b, 11b at the junction surface between deck and the hull base section on every side with remaining that in the zone of displacement this plane inclined also is a design mock-up that is used for reducing the recess effect of moonpool circle zone.Except the deck district to the lower horizontal neutral axis 20 directions displacement of the steady component of stress level of ship, this will help to reduce the stress concentration around in the zone of moonpool 2.The technical scheme of Fig. 3 also is shown among Fig. 6 with the form of top view.

According to the present invention, deck or hull base plate can change according to desirable steady component of stress level towards the displacement degree of horizontal neutral axis 20 directions of ship, and to account for main will be about determining the position of these decks and hull base plate to the actual foundation relevant with the design of ship simultaneously.

Fig. 7 illustrates has a Double bottom and " two " deck and the cross sectional drawing at the ship of the moonpool 2 of central authorities' setting.According to the present invention, be shifted to the horizontal neutral axis direction of ship with respect to all the other deck districts and territory, hull base area in the front side of moonpool and/or the deck district and the territory, hull base area at rear side place.In Fig. 7, this realizes by removing upper deck and lower hull base plate in double-deck and Double bottom structure, so as to deck area and territory, hull base area vertically being moved on to the position of lower deck and upper hull base plate.Local stress recess around moonpool has been moved to the lower position of steady component of stress level in cross-sectional plane.Make the steady component of stress level reduce by 20～40% if such displacement reaches, estimate roughly that then it can have the effect that will improve about 100～200% fatigue life.

Fig. 8 also illustrates the cross sectional drawing of the hull with a moonpool 2, wherein is provided with a double-deck and a Double bottom.In this case, by horizontal surface at the bottom of the independent hull also is set between an independent deck level and the upper base in the Double bottom structure being set between upper deck in double-deck structure and the lower deck and going to the bottom, the horizontal neutral axis direction that vertically goes up to ship in the deck district and the territory, hull base area of the every side of moonpool is shifted.

Fig. 9 illustrates the cross sectional drawing of the hull with moonpool 2, wherein is provided with at the bottom of a single deck and the single hull.In this case, horizontal surface is irrelevant at the bottom of the displacement in the deck district of the every side of moonpool and territory, hull base area and any lower deck horizontal surface or upper hull, only is vertically to have obtained the favourable effect of the present invention towards the horizontal neutral axis direction displacement of ship by the part with deck district and territory, hull base area here.The displacement in deck district and territory, hull base area needs not be symmetry, does not promptly need them to horizontal neutral axis direction mobile phase distance together.Equally, there is no need to make deck district and territory, hull base area all to be shifted, this situation is shown in Figure 10.This illustrates the cross sectional drawing of the hull with moonpool 2, wherein has only the deck district vertically to be shifted towards the horizontal neutral axis direction of ship.

In the scope of above-mentioned each exemplary, the ship with one or more moonpools all is possible, wherein the one or more zones between these moonpools can be vertically towards the horizontal neutral axis direction displacement of ship.Displacement need be not symmetrical about neutral axis, and promptly deck and hull base plate do not need mobile phase distance together, perhaps have only one of them vertically to be shifted.And if having moonpool more than two, it can be suitable for having different vertical displacements between different moonpools.No matter how many moonpools that is arranged in the hull has, it can be suitable for making in deck district that is positioned at sternmost moonpool rear and the displacement of territory, hull base area, and make in deck district of going up top moonpool the place ahead along the longitudinal direction and the displacement of territory, hull base area.These displacements of ship need not be onesize, do not need yet with several moonpools between deck and/or any displaced phase of hull base plate related.After the moonpool of two ends of going up along the longitudinal direction the vertical direction displacement of the deck in side and the place ahead and hull base plate can also with combine with progressively segmentation straight line junction surface or approximate arcuate engagement portion between all the other decks and/or the territory, hull base area in the displacement zone.

Claims

1. ship that marine operation is used, in its hull, have one or more openings that run through fully or partly run through, it is characterized in that, be in or be in basically between the described opening and/or described opening near deck and/or territory, hull base area be displaced to apart from the nearer position of the horizontal neutral axis of ship with respect to remaining boat deck and/or territory, hull base area.

2. according to the ship of claim 1, it is characterized in that the zone that is between the zone of remaining boat deck and territory, hull base area and displacement basically is progressively segmentation.

3. according to the ship of claim 2, it is characterized in that being on the deck of the generation displacement of the opening part of ship and the zone between territory, hull base area and all the other decks and/or the territory, hull base area is progressively to be segmented into one or more snippets.

4. according to the ship of claim 2, it is characterized in that, be on the deck of the generation displacement of the opening part of ship and/or the zone between territory, hull base area and all the other decks and/or the territory, hull base area and have the shape near linear junction surface.

5. according to the ship of claim 2, it is characterized in that, be in the deck of the generation displacement of the opening part of ship and/or the shape that the zone between territory, hull base area and all the other decks and/or the territory, hull base area has approximate arcuate engagement portion.