Oil companies are evacuating some Gulf of Mexico oil rigs in advance of Tropical Storm Isaac.

For now the storm is close to the Dominican Republic and Haiti. But oil installations would be at risk if it heads to the Gulf of Mexico and reaches hurricane strength.

BP said Friday it has begun evacuating all workers from its Thunder Horse platform in the eastern Gulf of Mexico, and will suspend oil and natural gas production there. It is also evacuating non-essential workers from offshore facilities in the central Gulf.

Murphy Oil Corp. said it is shutting down drilling operations in the Gulf, and will evacuate all non-essential workers on Friday and Saturday.

Royal Dutch Shell PLC said it was getting ready to evacuate all personnel in the eastern and central Gulf of Mexico not essential to production and drilling operations. It said had suspended drilling in some locations, but oil production had not been halted.

Apache Corp., the oil services company, also said it is evacuating non-essential workers in the eastern Gulf of Mexico.

Diamond Offshore Drilling Inc. said it was clearing non-essential crew from a rig in the central Gulf Friday and Saturday. It also planned to evacuate a rig off Pascagoula, Miss., on Monday. Diamond said it does not plan currently to evacuate workers on its third rig in the western Gulf.