Chevron Corp.'s Knotty Head discovery, the deepest well ever drilled in the Gulf of Mexico, holds about half as much oil and natural gas as originally estimated, said Nexen Inc., a partner in the project.
The discovery, announced in December, probably holds the equivalent of 200 million to 500 million barrels of oil, less than an earlier estimate of 350 million to 1 billion, said a spokesman for Calgary, Canada-based Nexen.
