Short Answer= No
Background info on each type of medical:
ENG1 (Seafarers Medicals) are the main medical fitness certification for those who work on ships/vessels at sea.
A OGUK (formerly UKOOA) medical certification is generally accepted worldwide, for offshore operations.
If a UK/EU based person is not intending to work solely as ships crew, and is expecting to work in the Oil and Gas industry, then ENG1 is not generally accepted.
They would, in almost all circumstances, require an OGUK medical and it must have been carried out by an approved OGUK doctor, not just any local GP. The medical is valid 2 years, for all ages.
In General terms the OGUK medical is accepted by many countries for working offshore. As ever, there are always exceptions to the general rule.
Cable and Alternative Energy Industries may also have different requirements.