RAK shuts off high pressure well in Oman
Posted: 31 March 2008
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Rak Petroleum Oman Limited is exploring the causes of the high pressure water and gas release reported in Al Jariya-1 well which has been shut off last month, the company said.
The exploration well, located on the Jebel Hafit prospect in Block 31 adjacent to the border with Abu Dhabi, showed an unexpected flow of liquid and gas that complicated rig operations.
“Despite some serious complications in early February, which we believe resulted in an underground blowout, we are confident that we have not compromised the main target, Shuaiba reserves, and that the Natih reserves also remain prospective,” said Peter Sadler, CEO, Rak Petroleum.
According to the company, while drilling at a depth of 5,131 metres, a zone of high pressure was encountered. Fluids flowed to a containment pit and after a few hours the flow was shut off at surface.
The team, meanwhile, examined rock cuttings from the formation encountered close to the bottom of the hole, to estimate approximate age while exploring the causes of the high pressure water and gas release.
It was discovered that drilling has reached a limestone unit of Campanian age, which is some 7 million years younger than the first target - the Natih formation - which is of Cenomanian age, the company said.
“This information clearly indicates that the Natih, which represents around 20% of targeted reserves, still lies between 20 metres and 180 metres deeper than the furthest point currently reached,” Sadler added.
This contrasts with the first reservoir objective, the Natih formation, which is a shelf carbonate of Cenomanian age, some 7 million years older.
“With the bulk of the targeted reserves lying a few hundred metres deeper in the Shuaiba formation, under the Nahr Umr shale, a regional seal,” he said.
Rak Petroleum are currently finalising plans based on these recent findings, in conjunction with the Ministry and Indago.
“We have been working closely with the Ministry of Oil and Gas, in Muscat, and our partners Indago to assess our options, which include executing a sidetrack,” he added.
Rak Petroleum estimates it will take approximately 3 weeks to place the well in state where the sidetrack could be executed with the required specialist equipment (expandable casing).
Rak Petroleum said they are working with a team from well control company Boots & Coots on how to manage high pressure in the well at the surface and conditions at the bottom of the hole.
The company said it is allowing time for over pressure to dissipate, that may result in moving the rig and drilling the next exploration well before returning to complete operations at Al Jariya.
Rak Petroleum is ‘the operator’ of Block 31 holding 50%, in partnership with Indago Petroleum Limited, which holds the other 50% interest. |
