CARACAS, (Reuters) – A Venezuelan natural gas  exploration rig sank in the Caribbean sea yesterday, less  than a month after a deadly explosion in the Gulf of Mexico  destroyed a BP-owned oil rig and created a natural disaster.

Most of the 95 workers escaped by boat after water  apparently rushed into one of the giant submarine rafts  supporting the football field-sized structure. The captain and  three engineers stayed to try and fix the $200 million rig.  They dived to safety just as it lurched into the waves. There was no gas leak or threat to the environment, the  government said.

Energy Minister Rafael Ramirez said the well being explored  by the Aban Pearl rig had been safely sealed, and he rejected  any comparisons to the BP accident, which killed 11 people and  triggered one of the world’s worst oil spills.

“This is different from the Gulf of Mexico, because it is a  testing well,” Ramirez told Reuters.

He flew to the site near Trinidad and Tobago yesterday:  “The rig sank completely … there is nothing to see.”

The Aban Pearl was the first offshore gas rig operated by  state oil company PDVSA, and state television frequently  portrayed it as evidence of Venezuela’s engineering prowess.

Venezuela has been producing oil for more than a century,  almost all of it from onshore or the inland Lake Maracaibo.  Offshore drilling, especially deep water production, is  expected to provide more of the world’s oil supply as  production in onshore fields declines while demand rises.

The BP spill has prompted a push for tighter offshore  drilling regulations in the United States, and Venezuela’s  accident could bring further scrutiny to offshore exploration.  Many experts said the second major rig collapse in two months  was likely to renew criticism of PDVSA’s operational record.

“This is adding PR insult to injury,” Tyler Priest,  director of global studies at the Bauer College of Business,  University of Houston, and author of a book about Shell’s  offshore Gulf of Mexico activities.

President Hugo Chavez broke news of the accident at the rig  — owned by India’s Aban Offshore in alliance with  Singapore-based Petromarine Energy Services Ltd — at 3:11 a.m.  (0741 GMT) from his Twitter account, @chavezcandanga.

Critics say Chavez wrecked PDVSA by firing thousands of  managers and technicians after a strike in 2002. The company.  the main financer of his socialist revolution, has suffered  cash flow problems on lower oil prices.

Venezuela, one of the world’s leading oil exporters, has  endured fires and maintenance problems at its network of  refineries in recent years. Nationalization of foreign-owned  projects, new foreign investments and higher taxes have  bolstered PDVSA’s coffers.

The Latin American OPEC nation sits on some of the world’s  largest offshore natural gas reserves, but PDVSA is not yet  producing offshore gas. Fears of rule changes and pricing  issues mean the company has struggled to attract extraction  investment from foreign companies with the right experience.

Ramirez said submersible robots would probe the cause of  the accident, which appeared to be a sudden surge of water into  one of the submarine rafts that the rig’s legs float on.

He said safety valves and other mechanisms have sealed the  well, with no risk of a leak. The rig owner would likely try to  refloat it, and two more exploration rigs are traveling to  Venezuela from India, he said. Aban Offshore’s shares fell by  1.51 percent to 1017.35 rupees yesterday.