SapuraAcergy wins Devil Creek development project pipeline contract (Ref : http://www.offshore-mag.com)

Published: Oct 2, 2009


Offshore staff

LONDON -- Apache Energy has awarded SapuraAcergy a $170-million contract for the Devil Creek development project (DCDP) offshore Australia.

SapuraAcergy’s scope of work involves the transportation and installation of 91 km (57 mi) of 16-in. (41-cm) rigid pipeline including a shallow water beach approach, subsea tie-in, and stabilization works together with a wellhead platform of a 1,700-metric ton (1,874 ton) four leg jacket and a 450-metric ton (496-ton) topside processing module.

Engineering and project preparations will begin immediately in Kuala Lumpur and Perth. Offshore installation is scheduled to begin in late 2010 using the positioning heavy lift and pipelay vessel Sapura 3000 and third-party support vessels.

10/02/2009

PIPELINE SPANNING ANALYSIS

Introduction

Assessment of pipeline where determining the acceptability of pipeline freespan without effected the structural integrity, which was measure the allowable span of pipeline with respect to certain criteria as per below:


-Static stress cross flow vortex shedding for the maximum design wave data combined with steady current.
-In-line vortex shedding using steady current only (no wave induce current)


A lot of factor that contribute the pipeline span like


-Uneven seabed
-Pipeline crossing
-Coral


Static Spanning



To maintain the consistency with other features in pipeline, span length based on static stress considerations are governed by:


-Selfweight and coatings
-Environmental factor
-Operational Factor
-Hydrotest Factor


All method of pipeline spanning analysis is according to DnV 81 as follow:

Dynamic Spanning


Dynamic span is to check the allowable span for installation, hydrotest and operation under the steady state current conditions.

Analysis is according to DnV 81 which fluid flow passing a free span that cause unsteady flow patterns due to vortex shedding, which may lead to oscillations of the pipe. vortex shedding frequency may coincide with, or be a multiple of, the natural frequency of the pipe. Harmonic or sub-harmonic excitation of the free span may then result.

SYMETRIC VORTEX SHEDDING

WEAK ALTERNATE VORTEX SHEDDING

STRONG ALTERNATE VORTEX SHEDDING

Swiber to lay Myanmar gas lines (Ref : http://www.offshore-mag.com)

Published: Nov 25, 2009


Offshore staff

SINGAPORE -- Swiber Holdings has won its first pipeline installation contract offshore Myanmar. An unnamed oil and gas company has issued a Letter of Award valued at $77 million for laying of 150 km (93 mi) of subsea gas pipelines.

Preparation for the project should get under way next month, with the installation program due to be completed in 2Q 2010.

Swiber is expanding its vessel pool, in anticipation of increased demand for offshore construction work. The fleet currently comprises 34 offshore vessels and 10 construction vessels, and Swiber expects to own and operate a total of 52 vessels by 2011.

11/25/2009