Gazprom searching for rig to drill in Mahanadi block

Vol 12, PW 3 (26 Jun 08) Exploration & Production

Anyone interested in offering a semi-submersible to Gazprom for its Mahanadi Basin drilling campaign has until 10am local time on July 7 to collect pre-qualification documents from the company’s Delhi office.

Most will have collected the documents well before but those who leave it to the last minute can rest assured they’ll have five hours to fill in the forms before they are opened at 3pm on the same day! Gazprom wants to mobilise its floater in May next year on a 10-month contract to drill a single â€کfirm’ well and possibly a second â€کoptional’ well at NELP-I exploration block NEC-OSN-97/1, where it has already drilled two wells, with mixed results. “The exact drilling locations will be finalised only when results of the seismic come in,â€‌ reports a source.

“Drilling the optional well depends entirely on the results of the â€کfirm’ well.â€‌ In September or October this year Gazprom wants to shoot 1060-lkm 2D over this block, located near NEC-OSN-97/2 (NEC-25), where Reliance has announced a string of discoveries.

Gazprom expects this â€کfirm’ well to be in water depths of between 50 and 150 metres and TD to be around 5000 metres below the seabed to Palaeocene formations. Gazprom drilled a disappointing first well at this block in December 2006 in 78 metres water depth to TD of 2400 metres, revealing only a small, non-commercial gas formation.

But its second well, drilled in March 2007 in 110 metres water depth to TD of 4450, was more promising, revealing “a big gas formationâ€‌ at a bottom hole pressure of 5000-psi and bottom hole temperature of 130 degrees Celsius. Gazprom was forced to abandon the well before testing as it developed a “kickâ€‌ with potentially devastating consequences.

“It came very close to a blow-out,â€‌ we hear. “Gazprom used between 2.16 and 2.20-ppg mud weight at this well.

â€‌ Drilling crew averted a crisis by quickly plugging the well and pulling out. But because of its harrowing experience Gazprom is now insisting on a minimum 15,000-psi BOP (Blow Out Preventor) stack for any floater it hires.