Extended Well Tests

Extended Well Tests

Mooring Systems offers a single point of supply for the equipment, engineering skills and expertise needed by oil and gas operators conducting extended well testing (EWT) in heavy oil fields.

In addition to comprehensive equipment supply, our partners include independent engineering design and analysis consultancy RiserTec and construction specialist Rig Engineering, enabling us to supply a complete heavy oil EWT solution.

North Sea – Heavy Oil EWT

For one operator conducting a heavy oil extended well test (EWT) in the North Sea, Mooring Systems was asked to supply a Quick Connect Disconnect (QCDC) hose transfer system, linking the drilling rig to the DP off-take vessel.

The off-take vessel docked at Mooring Systems’ quayside facility in Montrose for loading a 390mt export Flowline together with a polyurethane sleeve on the inboard side of the hose to act as a bend restrictor protecting the hose. The Flowline consisted of 2 x 40mt of Dunlop 6” hose 1 x 300mt of Manuli 6” hose , a swivel , 5mt Taurus jumper hose, crossover spools a spring loaded valve, and lower MIB connector.

Riser Tech Ltd performed all the analysis required for this task. These results were used to calculate the settings on load monitoring equipment on the QCDC. Also the safe distance, between the rig and vessel. With all the hose onboard, a 24hr pressure test took place before the ship sailed to the field.

Following engineering analysis, Rig Engineering, the QCDC package and Hydraulic Power Unit (HPU) were shipped offshore, installed on the rig and commissioned. Once all system tests were complete, a trial run was conducted with the off-take vessel.

When the rig was ready, all the valves were opened and the crude oil flowed to the off-take vessel’s tanks in batches. After the test was complete, the hose was flushed, disconnected and passed back to the off-take vessel.

For the ETW project Mooring Systems supplied a supervisor and two rigger / operators, constantly monitoring the load tensions, and were available 24hrs a days should there be a requirement to let the hose go.