This application is a U.S. national stage of PCT/NO2013/050208, filed on Nov. 25, 2013 which claims priority to Norwegian Patent Application No. 20121480, filed on Dec. 7, 2012, the contents of which are each incorporated herein by reference in its entirety.
The present invention relates to a guiding assembly for a piping system for connection to a well producing oil or natural gas, exporting these products or injecting fluids to improve the pressure of the oil or gas being produced. The piping system connects the well at sea bottom to a floating structure in the sea.
Piping systems connecting floating structures to the sea bottom may be designed with a flexible catenary shape or with a near vertical configuration. Such near vertical piping systems require that a constant tensile force is maintained when the floating structure is displaced due to wind, waves and current or by warping. The varying length of the piping system due to such lateral motion must be accommodated by means of maintaining the tension as the top of the piping system moves horizontally. This may be accommodated by hydraulic equipment, by buoyancy or by other means.
At the bottom of the floating structure, the piping system requires a guiding structure which can accommodate sliding of the piping system. The piping system may also need a means of accommodating angular displacement at the bottom of the floating structure.
Current technology consists of combining rigid or flexible guide tubes with sliding metal bearings or rubber bearings which may be reinforced with metal lamella.
The current technology is illustrated by U.S. Pat. Nos. 4,185,694, 5,683,205, 6,884,003, 7,067,201, and 7,217,067.
The object of the present invention is to guide the piping system with lateral support with respect to the floating structure at its bottom such that the piping is free to move in a near vertical direction and that the lateral motion of the floating structure is accommodated.
The object of the present invention is obtained by a prismatic guide tube supporting a conforming prismatic anchor for a piping system as defined in claim 1. Advantageous embodiments of the prismatic guide tube supporting rollers bearing on a conforming anchor structure for a piping system are defined in the dependent claims.
The present invention uses roller bearings which are not as prone to wear and which can accommodate the uneven surface of a long guide tube, e.g. by making the rollers from pre-compressed flexible tubes, such that the bearings at all times maintain contact with both supported surfaces. By using rollers, their stroke is reduced to half the vertical displacement of the piping system relative to the floating structure.
Further details of the invention will be described below with reference to the exemplifying embodiments shown schematically in the appended drawings, wherein:
The flexible rollers 3 are of a tubular shape such that they may, if desirable, be pre-compressed in order to accommodate unevenness in the surfaces of the prismatic tube 4 and also of the surface of the prismatic anchor 1. The surface of the rollers 3 may also be covered with a resilient material.
It will be understood that the invention is not limited to exemplifying embodiments described above, but may be varied and modified by the skilled person within the scope of the following claims.
Number | Date | Country | Kind |
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20121480 | Dec 2012 | NO | national |
Filing Document | Filing Date | Country | Kind |
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PCT/NO2013/050208 | 11/25/2013 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2014/088420 | 6/12/2014 | WO | A |
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Entry |
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International Search Report International Patent Application Serial No. 20121480; dated May 23, 2013, 2 pages. |
Number | Date | Country | |
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20150330159 A1 | Nov 2015 | US |