Shallow submerged ice platform
(57) Abstract:Shallow submerged ice platform designed for operation in Arctic waters. The inventive within the platform sloping sides of its base above the water line is made into a domed shape to the upper deck and below the water line is made moveable in the plane of the non approaching to the bottom of the water area. This form of flanges prevents the concentration of large masses of ice on the upper deck substructure. 3 Il. The invention relates to the development of the continental shelf, namely the artificial Islands, and with the greatest effect can be applied for operation in the Arctic latitudes.The main problem of the use of the exploration and exploitation of offshore drilling platforms in the Northern latitudes is the continuity of its work in terms of contact with the ice field. The design of the platform must be able to effectively withstand the pressure of moving ice field.Known operational offshore platform for polar latitudes (U.S. patent N 4260292, CL 405-217 from 1981), containing pricopoaea barge, upper deck which vozvyshaev is the possibility of heating of the walls mentioned pyramidal body.The upper structure supported by columns on the deck of the barge, placed above the moving ice, and its dimensions do not exceed the dimensions of the barge.For all the good qualities such shallow platform it is not devoid of drawbacks, the main of which is ineffective opposition to the pressure of the ice field. Sloping walls of the pyramidal housing facilitate the cracking of the ice, but his arm crawl against the deck of the barge. While the hummocking reaches a height of up to 8 ice thickness. It is easy to see that the accumulated layer of ice continues to move, reaches the supports of the upper structure and can destroy them.Another important disadvantage is unreasonably high total mass of the platform due to the full upper surface of the housing. In this case posted by the engineering and technological equipment, residential and office space. All this affects the weight characteristics and, ultimately, affects the increase in precipitation. As a consequence, the platform cannot be used in shallow water (at depths of 3 to 10 m). There is a construction based on the bottom of the caisson for use in Arctic conditions (U.S. Patent N 4479742, CL 405-217 from 1984 - prototype). The caisson viarouge and contributes to the destruction of the impending ice fields.Although this design is clearly improves performance (improving the ability of the opposition to the movement of the ice field by its destruction), but nevertheless it is obvious that this wall can not be infinitely high enough to eliminate the concentration of ice hummocks on the deck of the caisson. It is theoretically possible, but to ensure the strength characteristics in such wall, you need to invest so much scarce metal that exceeds reasonable limits.The present invention is to prevent a dangerous concentration of large masses of ice on the upper deck substructure shallow submerged ice platform by forming referred to the upper deck.The problem is solved in the shallow submerged ice platform containing the submersible to the bottom of the water area of the supporting base with inclined to the horizontal flanges on the upper deck hosts the surface of the structure, and the side above the water line is made into a domed shape to the upper deck and below the water line into the plane, asymptotically approaching the bottom.The proposed solution preditah">The ice platform, as it is represented in the drawing, includes upper structure 1 (drilling complex) and the support base 2, consisting of an upper deck 3 - its surface part and soles 4 - the underwater part. Upper deck 3 above the level of the ice field, in the longitudinal and transverse directions made dome 6, near water edge which merges into the plane 7. The platform is installed on the bottom 8 of the water. In addition to the drilling complex features a tower design 9 for home (office) premises and helipad.To perform drilling operations in shallow water submersible ice platform in a floating state is transported to the place of registration. Known means, on the point of setting the platform ballustrade and its base is lowered to the bottom 8. This is partially plane 7 are above the water, and partially submerged in water and asymptotically approaching the bottom 8. This is done for the next goal. Ice fields in the Arctic reaches a thickness of up to 2 m of Course, most of the 5 ice is under water. In shallow water (platform, in particular, is designed for depths up to 10 m) as the ice moves 5 its underwater part, meeting with non approaching the bottom of the PLO is valuutta backwards, and sideways, nagromozhdenie each other, forming hummocks up to 8 ice thickness height. Reaching a certain weight and height, the ice begins to slide with a domed surface 6. Upper deck 3 has mentioned domed pogib 6, both longitudinal and transverse (Fig. 3) directions. Therefore overlapped blocks of ice falling on the dome deck, under its own weight roll overboard and thus, for the most part do not reach drilling facility and tower 9. A small mass of ice, reaching this complex cannot any serious threat to its integrity.Thus, the proposed formation of the upper deck 3 allows to increase the effective confrontation of the platform moving ice field. This result contributes to the fact that steel structures 1 and 9, located above the level of the ice, are the minimum required sizes. This allows the lowest cost to ensure their strength properties. While most technological equipment transferred to the supporting base 2 and is almost not affected by ice. Shallow submerged ice platform, containing the supporting base with a sloped the e side above the water line is made into a domed shape to the upper deck, and below the water line extend in a plane non approaching to the bottom.
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