June 2013, Vol. 240, No. 6

Features

OMS Measures Pipe Ends Destined For Congo River Crossing Pipeline

Specialist pipe measurement technology company Optical Metrology Services (OMS) Ltd, recently completed measuring more than 19,000 pipe ends for Bredero Shaw at its pipe-coating facility in Leith, Scotland. The pipes are destined for use on Chevron’s technically challenging Congo River Crossing (CRX) Pipeline project.

In two separate mobilizations, OMS staff measured a total of 19,402 pipe ends (20-inch and 22-inch OD), using its automatic Pipe Checker laser-based measurement tool. OMS measured the internal- and outside-diameter profile (i.e. thickness) of the pipe ends immediately after the pipe preservation coating removal process, thereby avoiding any delays to Bredero Shaw’s overall production process. OMS staff carried out these measurements in a limited, two-minute timeframe.

As Jim Buston, senior business executive at OMS commented: “This was an unusual, challenging pipe measurement survey in the sense that our staff had to take measurements in line with the plant’s production process, within such a limited time window.

“We, therefore, deployed six OMS staff in total, three per shift working across two shifts. During storage, the pipes had been lined with a special preservation coating, which had to be removed first by Bredero Shaw. Our crew then measured the pipe ends within the two-minute window: one person was deployed at each end of the pipe, with two Pipe Checker Tools working simultaneously, with another engineer floating between the two ends.

“There were no delays to Bredero Shaw’s production process throughout the entire pipe end measurement process. Our work simply slotted into the customer’s process without causing any disruptions at all,” Buston explained.

The pipes were measured 12mm from the pipe end. As well as providing Bredero Shaw with general dimensional inspection of pipe ends during the preservation-coating removal process, the measuring process allowed OMS to analyze the pipe ends in comparison to dimensional specification criteria, including likely fit-up parameters.

The CRX project is a challenging one. The pipes will be installed in extremely fast-flowing currents at depths of up to 117 meters. The pipes are designed to transport 250 MMcf/d of gas, fed from Chevron’s two blocks off Cabinda.

From two platforms installed on either side of the Congo River canyon, Chevron has drilled a “well-intersection conduit” – a tunnel created by two wells drilled from either side of the canyon, and intersecting at a point below the canyon riverbed. This conduit will hold the subsea pipelines, preventing them being exposed to the fast-flowing currents of the Congo River, as it enters the Atlantic Ocean.