Floating caisson for mining and drilling in the open sea (options)
(57) Abstract:Floating caisson is designed for drilling and production in the open sea. The caisson is able to float by the buoyancy tanks and maintained in a predetermined position by mooring. The caisson has a Central well through which pass the vertical pipe, designed for drilling and/or production. One or more plates are of the caisson in the radial direction below the water surface. These plates provide additional mass and resistance movements that occur under the influence of waves due to the increase of the period of oscillations of the caisson. The design allows you to build the caissons shallower, i.e., to reduce their cost. 2 S. and 1 C.p. f-crystals, 3 ill. The invention relates to the field devices located in the open sea and designed for drilling and production in the open sea, in particular to the caissons.Previously used floating structures for drilling and production, had vertically mounted floating body, the upper part of which rose above the water, and the lower part was submerged to a predetermined depth. Such design-rayed at the m direction, and to the keel and side strokes. Have been proposed various means for reducing vibrations and pitching, which was a horizontally positioned elements spaced along the longitudinal axis design (US patent 4516882). The distance between these elements was large enough. The elements act as balancers when balancing, rolling, and, in addition, regulate the buoyancy of the caisson. Known design additionally contained anchor system, and mooring. Furthermore, the design could contain ballast. The disadvantages of the known designs should include low efficiency of damping.The technical problem to be solved by the present invention is directed, is to develop a design that is more efficient damping of vibrations.To solve this problem it is proposed to use the caisson performed with the opportunity to stay on the surface during drilling and production in the open sea, and the caisson contains at least one plate passing radially outwards from the casing below the water level in the working position of the caisson. When the caisson preferably contains numerous mooring, kadh in said plates, passing in a horizontal direction. According to the second variant of the invention it is proposed to use the caisson performed with the opportunity to stay on the surface during drilling and production in the open sea, and the caisson contains many plates, passing in a radial direction outward from the caisson lower the water level when the caisson is in the working position, and each of these plates has a diameter that is approximately 1.75 times the diameter of the caisson, when said plates are separated from each other at a distance that is approximately 60 % of the diameter of the caisson.Hereinafter the invention will be illustrated with the use of graphic materials, where Fig. 1 shows an isometric image structures corresponding to the present invention. In Fig. 2 shows a side view (in section) of a design corresponding to the present invention. In Fig. 3 shows a graph which illustrates the influence of the distance between the plates and the diameter and number plates.In Fig. 1 shows a construction corresponding to the present invention, indicated overall by the reference number 10. As follows from Fig. 2, the buoyancy of the caisson 10 the obligation of the cross-section of the casing 10 can be changed in its length, preferably uniform along the entire length of the cross-section. The caisson 10 can contain a variable volume ballast 14, compartments 16 oil storage, differentia tank 18 and the stationary ballast tank 20. As follows from Fig. 1, the casing 10 may be retained in a predetermined position by mooring 22. Vertical pipe 24 can be used for drilling or mining and pass through the Central well 26 in the casing 10 to the blowout preventer on its surface. Drilling rig 28 may be located on the upper surface of the caisson 10.Unlike typical caisson with the draught order 152,4 - 213,4 m floating caisson, corresponding to this invention, has a draught of about 91,4 - 121,9 m In this case, the small oscillations in the vertical direction extinguished by the use of a variety of plates 30. Plate (plate) 30 is installed in the lower end of the casing 10 and spaced along the entire length of the caisson 10. Plate 30 is rigidly fixed in such a way as to pass through in the radial direction of the caisson 10, positioned horizontally relative to the surface of the water 32 in the case when the caisson is located in the sea in the working position. Plate 30 when the oscillations are capturing a lot of water, materialov maximum energy waves. This allows us to use less draft caisson. It should be noted that the smaller the length of the caisson and requires less effort when towing and when the transfer of the casing in a vertical position. In addition, this allows to reduce the consumption of steel in the construction of the caisson and, consequently, reduce its cost. This caisson can be used on smaller bodies of water. In this case, the upper part of the casing rises above the surface of the water approximately 15.2 m, supporting a drilling rig 28 and the deck 34. Although the graphic material shown that the plates 30 evenly spaced, but the spacing between the plates can vary depending on the desired effect on the period of oscillations of the caisson 10.In Fig. 3 is a graph that is built in the model tests carried out on various designs of tiles and slabs. Weight plates together with the captured water influences the increase of the apparent precipitation of the spar. For example, in Fig. 3 shows that the effect of having two plates, separated from each other at a distance of 0.06 D ( i.e., distant from each other at a distance greater than the diameter of the caisson 0.06 times), and when the diameter of the plate, equal to 1.5 D (i.e., 1.5 times the diameter of the caisson) have led the, is provided that the presence of four plates of diameter D and spaced from each other at a distance of 0.5 D will increase the apparent subsidence of almost six times the diameter.The distance between the plates and their size depends on the characteristics of waves, winds and currents, which are different in different parts of the world. For example, in the Gulf of Mexico, where the design of the caisson is mainly affected by the hurricanes, the required sediment upright caisson is 152,4 - 213,4 m to provide a smaller movement in the vertical direction. For caisson with limited draught of approximately 91.4 m and a diameter of about 30.5 m, the required effective length of the taking of water is approximately 91.4 m or three in diameter. It is evident from Fig. 3 shows that this can be achieved using four plates with a diameter of 1.5 D, separated from each other at a distance of 0.3 D - 0.5 D. If the spar has a diameter of 21.3 m, the corresponding increase in effective precipitation will require effective length of the captured mass, equal to four diameters. This will require an increase in the distance between the plates up to a size of approximately 0.7 D or to reduce the distance between the plates, the diameter of the plates will have to increase.For the North sea, where the wave period is greater need for effective asamer.In areas where the wave period is less than the distance between the plates and the diameter can be reduced.Lines 22 with one end attached to the anchor 30, fixed to the seabed 40 and the other end on the caisson 10. As shown in Fig. 1, a method of fixing the moorings 22 to the caisson 10 provides for the transmission of them through guides 36 in the plates 30. The guides 36 prevent wear and chafing mooring 22 and provide an opportunity to strengthen the mooring to the caisson 10 at any desired point along its length. Preferably, they are fixed to the upper part of the caisson 10.The caisson 10 can be made on the stocks in a horizontal position and then lowered into the water. Plate 30 can be installed after the caisson will be afloat. If the construction and descent took place in the shallow zone, the plates may be installed on the ship or afloat. Then the caisson can be towed on a deeper place and transferred in the vertical position with the dismantling of the remaining plates.Because there are many possible variants of realization of the invention, it is obvious that the examples provided in the application materials, should be taken as illustrative and not restrictive. 1. Floating Cassie who obici in the open sea, characterized in that it additionally contains at least one plate, which pass radially outwards from the casing below the water level when the caisson in position.2. The caisson under item 1, characterized in that it additionally contains many lines, each of which is attached at one end to the casing, and these mooring installed in the guide passing through the plate, oriented in a horizontal direction.3. Floating caisson performed with the opportunity to stay on the water surface and is designed for drilling and production in the open sea, characterized in that it further comprises a set of plates that pass radially outwards from the casing below the water level when the caisson in position, and each of these plates has a diameter that is approximately 1.75 times the diameter of the caisson, when said plates are separated from each other at a distance of approximately 60% of the diameter of the caisson.
FIELD: hydraulic engineering, particularly building bases and foundations, namely bridge piers, in water.
SUBSTANCE: method involves monitoring water obstacle in support building place, including investigating water parameters, recording water level in the course of year, determining floor shape, investigating floor ground, influence of outer disturbing forces and calculating weight and dimensions of support foundation case on the base of above parameters; producing hollow case with several cavities; moving case to installation place; submerging case in water; pacing thereof on floor; fixing case by piles and smoothing floor. Case submerging and placing operations are performed simultaneously with stabilizing vertical case position by performing control and filling of corresponding cavities. Bottom smoothing process is carried out by forcing artificial material, such as concrete layers with crushed stone interlayers, under case bottom. During case placing case is secured by blades built in case bottom and by piles inserted in cavities. Correspondence between case weight, number of blades, head resistance and side friction thereof for particular ground is determined to provide case stability on ground. Upper edge of submerged case is located above maximum possible water wave height. Rock fill is formed around underwater case part.
EFFECT: reduced time of support erection, increased reliability and stability, safety and service life, reduced labor inputs, possibility to erect supports in Arctic basin.
3 cl 1 ex
FIELD: stationary sea oil platforms.
SUBSTANCE: block has underwater support, made in form of two-level bench, formed by vertical beam cases and horizontal links, and also has support columns, connected to support. Horizontal links of bench are made in form of floating tanks, while links, placed along perimeter of lower level of bench, are separated by water-impenetrable walls on sections, provided with ballasting means. Method for mounting support block at the bottom of continental shelf includes transporting, ballasting of floating tanks and fixing support block at the bottom of water body. Support block is transported into wells drilling zone in planned position, sections of floating tanks are ballasted until lower level of support lowers into bottom of water body for 0.3-0.7 of its height, different and slants are evened and holding beams are inserted into cases of support with their following forcing into hard bottom portion and fixing in cases. Ballasting of sections of floating tanks and forcing of holding beams can be performed in pairs in diagonal planes relatively to center of lower level of support.
EFFECT: simplified assemblage, higher reliability.
2 cl, 12 dwg
FIELD: hydraulic engineering, particularly for forming temporary structures for enclosing closed in plane water area bottom part and space above the bottom part through the full water thickness.
SUBSTANCE: method of shallow tunnel construction involves forming structure enclosing closed in plane bottom part; removing water from the structure; performing works in dry structure and demounting above structure. Method of enclosing structure forming involves producing bottomless hydraulic enclosure with controlled floatability; transporting and moving thereof to tunnel path; immersing the enclosure in water up to reaching water area bottom by reducing floatability thereof and fixing enclosure with fastening means and anchor system; leveling upper enclosure part with horizon line and arranging cranage and platforms for building material storage on upper enclosure part; erecting cutoff walls inside space defined by enclosure; removing water from the enclosure; developing bottom ground by trench digging; constructing pile tunnel base; building foundation grill on pile tunnel base; locating composite or precast reinforced concrete tunnel sections on foundation grill; recovering initial floatability of the enclosure. Enclosure structure has movable fastening means formed as blades along vertical walls thereof.
EFFECT: increased tunnel reliability, reduced time of erection thereof.
4 cl, 4 dwg
FIELD: production of ice.
SUBSTANCE: method comprises producing a hollow near the ship's side, delivering air under the ice cover, the air volume does not exceeding the volume of the space defined by ice covering from the top, water from the bottom, and ice walls from the sides over the contour of the future hollow. The walls are frozen from top to bottom by means of direct nonseparable heat exchangers mounted in advance into the covering immediately behind the contour up to the bottom of the future hollow. The delivery stops and the bottom of the future hollow is frozen with the use of L-shaped nonseparable heat exchangers set into the covering simultaneously with the direct heat exchangers. As a result, a closed space is defined, which is stripped, and ice blocks are removed.
EFFECT: enhanced efficiency.
FIELD: hydraulic engineering, particularly underwater structures adapted for oil and gas well operation, preferably on shallow continental shelf having bottom covered with thick silt layer and in ice-covered period.
SUBSTANCE: platform comprises base, vertical pile holders connected with the base and positioning unit for drilling string and well-control equipment fixation. Base is formed as a structure with cavities filled with ballast. The structure is composed of hollow members and functionally divided into two areas. Positioning unit is arranged in the first area, another area including catching opening. Platform is additionally provided with removable mounting frame with production equipment installed on the frame. Arranged in lower frame part are inclined guiding means to provide access into catching opening during mounting frame connection with support platform base in underwater position.
EFFECT: reduced labor inputs for production equipment mounting and maintenance, increased reliability.
FIELD: offshore oil-field hydraulic structures, namely for building fixed platforms.
SUBSTANCE: support substructure comprises three-dimensional latticed structure having prismatic shape and composed of tubular members. The structure has vertical panels with posts, cross-pieces, struts and horizontal diaphragms connected one to another. Horizontal diaphragms have guiding nets for marine risers. The structure is secured to ground by main piles arranged in vertical posts and by foundation having additional piles, which is rigidly connected to tubular members of side edges of above structure. The structure is provided with ice-protection means formed as two truncated prisms of sheet steel and having beveled side ribs rigidly connected one to another by major bases. Marine risers are arranged inside prisms. Each prism of ice-protection means is rigidly connected with tubular members of corresponding diaphragms of three-dimensional latticed structure.
EFFECT: increased resistance to wave, seismic and ice loads, improved manufacturability and, as a result, reduced cost of permanent offshore structure building.
3 cl, 2 dwg
FIELD: offshore oil-field hydraulic structures, namely for building fixed platforms.
SUBSTANCE: method for forming support substructure by welding large blocks involves producing and serially connecting precast members to create flat units, namely panels and diaphragms; connecting flat units by tubular inserts and tubular links to create three-dimensional latticed structure. All operations are divided into four stages in accordance with technological order. The first stage includes forming tubular links and tubular inserts, pile sections and marine riser sections. The second stage includes assemblage of flat panels and diaphragms in horizontal position on corresponding mats. The third and the forth stages include simultaneous installation of flat panels and diaphragms and rigid connection thereof.
EFFECT: reduced labor inputs, time and cost for assembly work performing due to elimination of complicated tubular joints used as assembly units.
3 cl, 7 dwg
FIELD: ground hydraulic structure erection, particularly to decontaminate silt or bottom sediments in water bodies.
SUBSTANCE: method involves building protective dam along perimeter of silt and/or bottom sediment area to be protected; laying waterproofing layer along inner dam perimeter, wherein waterproofing layer height is 2 times as much as silt and/or bottom sediment layer; forming artificial ground massif of watertight ecologically friendly natural ground in water area inside the dam, wherein artificial ground massif thickness is equal to at least three thicknesses of silt and/or bottom sediment layer; forming above-water relief area having 2.5 m height over water surface; forming surface flow discharge system and planting greenery in artificial ground massif.
EFFECT: increased reliability, reduced contamination concentration, prevention of hazardous substances ingress in ambient space and improved ecological safety.
2 cl, 1 dwg
FIELD: marine hydraulic structures, particularly fixed marine oil and gas production platforms.
SUBSTANCE: method for pile installation with the use of handling machine involves driving each pile in conical hole made in guiding means fixedly secured to marine platform base; installing pile and guiding means in coaxial position by guiding device having body installed on guiding members of the base so that the body may be displaced and fixed in predetermined position; lowering pile to working position; installing guiding device above water level on guiding members of platform base in predetermined position, wherein the guiding device is made as cylindrical body part and cylindrical part of guiding member secured one to another and having crossing axes so that cylindrical part of guiding means and cylindrical part of guiding member of guiding device are brought into coaxial state by corresponding linear and angular guiding member displacement; securing guiding device body with guiding members of platform base.
EFFECT: extended technological capabilities and simplified method of pile installation in working position.
5 cl, 4 dwg
FIELD: marine oil production hydraulic structure building, particularly marine platform assemblage.
SUBSTANCE: method involves forming assembly units, namely support unit, load-bearing deck and block units of upper structure, at subassembly site; docking floating vehicle to subassembly site; serially installing assembling units on stockpile carts; moving assembly units from subassembly site to floating vehicle with the use of above stockpile carts; transporting thereof to assemblage site and performing successive mounting thereof with the use of crane-and-mounting ships. The successive mounting operation involves installing support unit on previously prepared ground; installing piles in corresponding bell-shaped guiders of the support unit; driving the piles and cementing thereof to create pile foundation; arranging load-bearing deck on struts and installation guiding bars having different heights and previously formed on support unit, wherein the load-bearing deck has seats for struts and bars receiving and connection thereof is carried out by successive alignment of above bars and seats.
EFFECT: increased efficiency of building equipment and floating vehicle usage; reduced building time, decreased number of operations to be performed at sea, reduced labor inputs and decreased costs of marine fixed platform building.
7 cl, 17 dwg