TDW assists pipeline valve replacement offshore Qatar

Offshore staff

DUBAI, UAE – TDW Offshore Services has completed a pipeline pressure isolation operation off Qatar.

Natural gas is transported from platforms offshore Qatar to seven LNG trains at an onshore process complex. To facilitate replacement of a defective emergency shutdown (ESD) valve on a primary export line, pressure isolation services were needed. The 38-in. (96-cm) pipeline runs from two wellheads in the offshore gas-condensate field to the LNG processing facility.

To isolate the pipeline section upstream of the ESD valve, TDW launched two 38-in. SmartPlug isolation modules using an existing pig-receiving trap onshore at the receiving end of the export pipeline.

The company deployed a remotely operated SmartTrack tracking and pressure monitoring system to map the location of each module as it travelled 600 m (1,968 ft) along the pipeline route, as well as to watch pipeline pressure.

One module was positioned upstream of the ESD valve, and the other downstream of the valve. The TDW team then set the modules and isolated the affected section to allow modifications on the valve to be safely performed.

The SmartPlug modules remained in the pipeline for eight days. Upstream pipeline pressure was maintained at 85 bar (1,232 psi) while the ESD valve bypass repair work was carried out.

During this period, TDW continually monitored the pressure of the line and pressures through the isolation modules. After the ESD valve bypass repair work was finished, the SmartPlug modules were used to hydrotest the integrity of the completed work to a pressure of 120 bar (1,740 psi).

The isolation modules were then unset, and all equipment was retrieved and demobilized. The entire operation was achieved without flaring product or venting of the line.

4/17/2012

Did You Like this Article? Get All the Energy Industry News Delivered to Your Inbox

Subscribe to an email newsletter today at no cost and receive the latest news and information.

 Subscribe Now

Whitepapers

Logistics Risk Management in the Transformer Industry

Transformers often are shipped thousands of miles, involving multiple handoffs,and more than a do...

Secrets of Barco UniSee Mount Revealed

Last year Barco introduced UniSee, a revolutionary large-scale visualization platform designed to...

The Time is Right for Optimum Reliability: Capital-Intensive Industries and Asset Performance Management

Imagine a plant that is no longer at risk of a random shutdown. Imagine not worrying about losing...

Going Digital: The New Normal in Oil & Gas

In this whitepaper you will learn how Keystone Engineering, ONGC, and Saipem are using software t...