The new unit was built as part of the company’s multi-billion dollar upgrade of the oil refinery.

BP refining and marketing segment chief executive Iain Conn said the start up of the crude processing unit at the facility has returned the refinery to its nameplate capacity of 413,000bpd and will initially process light, sweet crude.

"When the new coking and hydrotreating units are commissioned and operating at full rates in the second half of this year, the reconfigured refinery will have the flexibility to greatly increase heavy, sour crude processing, delivering an expected incremental $1 billion of operating cash flow per year, depending on market conditions," Conn added.

BP said the construction of the oil refinery upgrade project is 95% complete, while it expects to commission a new 105,000bpd gasoil hydrotreater, a large 102,000bpd coker and other associated units in the second half of 2013.

Once all the new equipments begin full operation, the refinery will be able to increase heavy, sour crude processing to about 80% of its overall crude run.