Centrica to limit operating pressure at Rough wells

March 26 (Reuters) - British utility Centrica Storage Ltd (CSL (Other OTC: CMXHF - news) ) said it will limit the maximum operating pressure at its Rough wells off the east coast of England after it discovered a potential issue with well integrity last week.

The company said on Thursday that it would limit the operating pressure to 3,000 psi at Rough, Britain's largest gas storage site. (http://bit.ly/1IA4nGV)

It expected the limit to be in force for up to six months.

This will reduce gas injection capability at the site, though gas withdrawal will be unaffected.

Pressure drives three possible operation modes at Rough: "two train" where two compressors are in operation; "single train" where one compressor is in operation and "Stop/start" where one compressor is run for a time and then allowed to relax.

"Continuous single train injection operations will now be expected to occur around a stock level of 22 terrawatt hours (TWh) to 26 TWh", the company said.

"Stop/start" single train injection operations will now be expected to occur around a stock level of 26 TWh and withdrawal will remain unaffected.

According to a CSL report published in December, there are 29 wells in operation at the Rough site, located below the seabed.

Last week, the company said the amount of stock in the Rough reservoir could be limited to a range of 29 TWh to 32 TWh (Reporting by Shivam Srivastava in Bengaluru, editing by Nina Chestney and Mark Trevelyan)