UK-BASED SPECIALIST measurement technology company Optical Metrology Services (OMS) Ltd has successfully completed a six-week pipe inspection study for BP Exploration (Angola) Ltd, Block 31 PSVM deepwater Development in Angola.
The contract, worth more than US$1mn to OMS, required OMS to carry out an initial sample survey of pipe ends, followed by the detailed laser dimensional inspection, the sorting and marking of more than 12,000 pipe ends, including critical, fatigue-sensitive, flow line sections.
As well as helping the customer to better implement the pipe end fit-up process and fatigue HiLo strengths, the study also ensured that the customer’s pipe welding time and counter-bore crew costs were minimised.
OMS’ customer is French company Technip, Main Contractor for the design, procurement, fabrication and installation of the Water and Gas Injection flowlines for the Block 31 URF 2 Programme workscope.
OMS worked closely with Technip’s local subsidiary in Angola, Angoflex Ltda. The Block 31 deepwater oilfield covers an area of 5,300 square kilometres and lies in water depths of between 1,500m and 2,500m.
Richard Gooch, Director of Technology at OMS commented: "OMS engineers measured every pipe end and then marked these with a calibration block group code, according to calibration blocks to be used for the AUT inspection. This sorting process enabled the most round pipes to be allocated to the more critical sections of the pipeline. Identifying and marking pipe ends in this way ensured the least possible disruption to Technip’s fit up process. The customer now has the basis for the fit-up of pipes to BP’s specification and HiLo fatigue strengths."
"The accurate fit up of fatigue-sensitive pipes is a highly critical factor when it comes to welding the pipe ends together. Not managing these issues can lead to delays in production and to weld problems, which in turn, can lead to stress concentrations in that region or expensive cut-outs and rework," he continued.
Managing pipe fit up requires extreme accuracy of dimensional measurements of the pipe ends. OMS used dimensional data from the measurement of the pipes to match pipe ends that had the same size and shape characteristics.
Using the OMS PipeChecker Laser technology, more than 2,000 measurements of the inside and outside diameter of the pipe ends in less than 20 seconds were taken, providing the exact shape of the pipes.
"Our on-site staff were helped enormously in their task by the local Technip engineers and Angolan staff and the excellent conditions of the site. The hospitality we received, as well as the recreational facilities and meals provided were excellent," says Gooch. "The site was also tidy, clean and there were no health and safety issues at all."
OMS is a specialist measurement technology company that provides measurement services and precision measurement systems to the oil and gas industry. A key focus for the company is in the dimensional measurement of oil and gas pipes or other similar structures such as aero engines, process industry tubes or manufactured cylindrical objects, where dimensions are critical.