Getting ready to test third zone at KG-OSN-2001/3

Vol 9, PW 7 (14 Jul 05) Exploration & Production
     

GSPC begins testing the third zone in its third and lucky well at KG-OSN-2001/3 sometime this week.

This test will be carried out in the 30-metre interval between 4642 metres and 4671 metres. GSPC has yet to decide on the choke sizes and other parameters, an industry source tells this report.

The third zone will be tested extensively and over seven days. Adds our source: GSPC is confident the third zone will yield good flow rates.

We understand two more zones will be tested before rig Perro Negro 3 is moved to her next drilling location. Each test at this well will last about seven days.

During the tests GSPC will also collect data to draw up the development plan for the gasfield. GSPCs third test follows the second test, which had to be prematurely abandoned due to complications.

Its plan was to test the second zone for three days but they had to terminate the test after one day. The second zone chosen for testing lay below the first zone, between 4775 metres and 5000 metres.

Within this 225-metres zone, GSPC perforated a 40-metre interval. While testing was on, says an industry source, there was a sudden influx of sand and gas at high pressure catching GSPC by surprise.

As a result only two choke sizes could be used but recordings were made only of the second choke. Gas flow of about 10m cf/d was recorded for about seven hours at a bottom hole pressure of 12,900-psi and surface pressure of about 6000-psi.

The high pressure sand shot up like a bullet and severely cut the choke, we are told. People present at the test had a lucky escape.

We are told that the choke was cut as if it had been sliced by a knife. Fears of a blowout were real but later subsided.

They had to change the ramp of the blow out preventor. GSPC terminated the test at the end of the first day and shut the well for 40 hours.