The high rate production test performed by Norsk Hydro on the Troll East structure during the summer of 1985 with the semi submersible drilling rig Treasure Seeker required that a large number of specially designed, modified or adapted equipment items were used in order to fulfil the test objectives and maintain safe operations. These were:
Jetting tool for casing cleaning.
Gravel pack floor manifold to ease operations.
Surface read out of downhole pressure and temperature through
cable on the outside of the tubing.
3 inch I.D. tester valve.
3.7 inch I.D. annulus pressure operated kill valve.
Full bore double gauge carrier.
5 inch I.D. sub-sea test valve.
5 inch I.D. lubricator valve.
5 1/8 inch bore flowhead.
Vertical high capacity separator.
32 channel data logger.
The use of this equipment together with other more commonly used equipment made the test a success.
Prior to drilling well 31/6-8 on the Troll East structure the decision to perform a (record) high rate gas test on the well, providing the required reservoir thickness and qualities were found, had been taken.
The test objectives were:
Define reservoir inflow performance at high and low rates.
Obtain test permeabilities and skin.
Obtain representative fluid samples.
Investigate pressure and temperature drops in the completion and tubing at low and high rates.
Define maximum productivity of the well system.
Optimize data acquisition of the well system.