Mitchell Drilling to restart CBM drilling for Essar

Vol 15, PW 17 (08 Mar 12) Exploration & Production

After a gap of nine months Mitchell Drilling is preparing to restart drilling at the Essar-operated 500-sq km RG (E)-CBM-2001/1 or Raniganj East CBM block in West Bengal.

On March 2, the Australian driller mobilised its Soilmec G55 rig to the block, where it joins a second Mitchell rig, RD-20. “Essar hired two rigs from us in November 2010 to drill 55 production wells,” reports Mitchell.

“So far we have drilled 27; another 28 are yet to be drilled.” Mitchell says it was forced to suspend drilling in June last year.

“First Essar didn’t have clearance from the environment ministry (in Delhi) to drill production wells,” said Mitchell. “That came in October 2011.

Then the West Bengal (state government) Pollution Control Board did not allow Essar to drill all the 55 wells in one go.” Essar eventually secured permission from West Bengal pollution authorities on December 7 last year.

“If all goes to plan and work is not held up because of the monsoon or any other reason,” Mitchell adds, “we can finish work in six months.” In West Bengal the three-month heavy rain monsoon season typically starts in June and ends in August.

Assuming no glitches, Mitchell predicts each rig will drill three wells every month and expects to finish drilling the remaining 28 production wells by August this year. All the remaining 28 production wells will be drilled to a maximum depth of 1200 metres.

Until now, the deepest of the 27 wells drilled so far by Mitchell was 1510 metres. Baker Hughes is charged with cementing and ‘frakking’, while Schlumberger and Halliburton will be charged with directional drilling.

Some of the Mitchell wells will be drilled to 300 metres vertical depth before deviating to become directional.