Seamless steel tube for use as a steel catenary riser in the touch down zone

Inactive Publication Date: 2008-09-18
TUBOS DE ACERO DE MEXICO
View PDF2 Cites 40 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0015]The present invention describes an upset SCR of novel low carbon chemical composition and microstructure which achieves higher improvement in the fatigue life as it is integral with the riser pipe section at the Touch Down Zone. The low carbon upset SCR achieves its desired properties by the thermal treatment which it is subjected to. The novel low carbon chemical composition and microstructure comprises in weight per cent, carbon 0.04-0.10, manganese 0.40-0.70, silicon 0.15-0.35, chromium 0.

Problems solved by technology

Such component is normally subjected to complex spectra of fatigue loading related to both the mobility of the floating platform and to the very large free span of unconstrained line from the seabed to surface.
The application of SCRs is challenged by, in some cases, the high fatigue damage at the Touch Down Zone (TDZ) from a combination of field specific parameters such as riser size, fluid characteristics, vessel motions, metocean parameters, soil conditions, and water depth.
In this zone, the riser experiences the highest level of cumulative fatigue damage.
The severity of fatigue loading in the TDZ is furthe

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Seamless steel tube for use as a steel catenary riser in the touch down zone
  • Seamless steel tube for use as a steel catenary riser in the touch down zone
  • Seamless steel tube for use as a steel catenary riser in the touch down zone

Examples

Experimental program
Comparison scheme
Effect test

Example

[0030]As illustrated in FIG. 1, the present invention describes an upset SCR of novel low carbon chemical composition and microstructure which achieves higher improvement in the fatigue life as it is integral with the riser pipe section at the Touch Down Zone. The low carbon upset SCR achieves its desired properties by the thermal treatment which it is subjected to.

[0031]The steel grade contemplated for use in the upset SCR of the present invention is X-65 (a yield strength of at least 65000 psi in the pipe body and in the upset ends).

[0032]The alloy design consists of a low-C (0.13 max), low-Mn (1.5 max) steel with additions of microalloying elements such as Niobium, Titanium (Nb+Ti 0.1 max), Chromium and Molybdenum (Cr+Mo 1.2 max). The purpose of adding these last two alloying elements is to increase hardenability and promote a martensitic-bainitic transformation on thick upset ends and pipe body achieving high strength. The carbon equivalent (CE) is designed not to exceed 0.43 as...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Temperatureaaaaaaaaaa
Temperatureaaaaaaaaaa
Lengthaaaaaaaaaa
Login to view more

Abstract

The present invention describes an upset SCR of novel low carbon chemical composition and microstructure as well as method of manufacturing the same, which achieves higher improvement in the fatigue life as it is integral with the riser pipe section at the Touch Down Zone. The low carbon upset SCR achieves its desired properties by the thermal treatment which it is subjected to. The novel low carbon chemical composition and microstructure comprises in weight per cent, carbon 0.04-0.10, manganese 0.40-0.70, silicon 0.15-0.35, chromium 0.40-0.70, molybdenum 0.40-0.70, nickel 0.10-0.40, nitrogen 0.008 max, aluminum 0.010-0.045, sulfur 0.005 max, phosphorus 0.020 max, titanium 0.003-0.020, niobium 0.020-0.035, vanadium no more than 0.10, copper 0.20 max, tin 0.020 max, and carbon equivalent 0.43 max and PCM no more than 0.23 and having a yield strength of at least of 65000 psi, the ultimate tensile strength of at least 77000 psi and YS/UTS ratio below 0.89 in material representing the pipe body, the transition zone and the upset end.

Description

FIELD OF THE INVENTION[0001]This invention relates to seamless steel tubes for use as steel catenary riser.BACKGROUND OF THE INVENTION[0002]In recent years, the interest in exploiting deeper water off-shore oilfields has increased sensibly. As a consequence, various solutions of marine production systems have been developed. The currently-available solutions are directed generally to semi-floating and floating production systems which are subjected to various movements with respect to seabed, mainly due to marine waves, currents and tides phenomena. The aforementioned systems are complemented by compliant riser systems compatible with mobile surface stations.[0003]Steel Catenary Risers (SCR) represents one of the most outstanding riser systems to be adopted in these challenging situations. Such component is normally subjected to complex spectra of fatigue loading related to both the mobility of the floating platform and to the very large free span of unconstrained line from the seab...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): E02D29/00C22C38/42C21D9/08
CPCC21D9/08E21B17/015C22C38/18
Inventor GARCIA, ALFONSO IZQUIERDOCARMONA, HECTOR MANUEL QUINTANILLA
Owner TUBOS DE ACERO DE MEXICO
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products