Mike Neal, chief executive officer of the Tulsa Metro Chamber, said the refinery expansion doubles the size of the refinery work force to about 500 people. Neal said the expansion perhaps is the largest ever by a private firm in Tulsa.

Sinclair officials said the expansion will increase refinery capacity from 70,000 to 115,000 barrels of crude oil per day. Sinclair refines diesel fuel as well as gasoline and had earlier prepared its diesel refining capacity to be able to produce clean-burning fuel to meet more stringent federal regulations.

The refinery is situated along the Arkansas River near the current Zink Lake. Spokesmen said the areas between the refinery and river will be land scaped and beautified in connection with the expected development of the river.

The investment in new equipment is expected to reduce odor as well as emissions. The odors typically come from sulphur and the reduction of sulphur emissions will reduce odors, already significantly improved.

Even with an increase of 57 percent in capacity, air pollution will decrease from current levels because of new equipment and better technology.

Oil built early-day Tulsa and sustained it for decades. In recent years its role has receded a bit, but it's

Harry F. Sinclair was a dominant figure in the early Tulsa development. He would have been proud of the refinery that bears his name.