TESORO CORPORATION AWARDS ONQUEST
4TH PROJECT FOR 2012

Leading Refiner Commissions Furnace Analysis at Anacortes Refinery

(Los Angeles, CA - September 13, 2012) San Dimas, Calif.-based OnQuest, Inc. has been commissioned to conduct a detailed analysis of three different furnace convection sections at the Anacortes Refinery in Anacortes, Wash.

The win marks OnQuest's fourth project from Tesoro in 2012, each from a different refinery.

"OnQuest continues to build trusted relationships with top refiners, as we apply industry-leading combustion engineering experience to helping them improve performance and optimize processes and production," said Randy R. Kessler, OnQuest's president and CEO.

OnQuest is a recognized leader in furnace revamps and retrofits, particularly for complex projects requiring completion in short turnarounds. As with other of its furnace analyses, the company will examine heater efficiencies and review existing equipment before deciding whether to recommended an upgrade to the units.

"Tesoro is a long-time client, and we look forward to exceeding the company's expectations in delivering this work," said Kessler.

Established in 2002, OnQuest engineers and designs specialized process plants for the new world of energy production, including for LNG, waste-to-energy, hydrogen and syngas plants. OnQuest has expertise in execution from engineering and design to delivery, including procurement and turnkey project management and construction supervision. OnQuest also designs direct-fired heaters and waste heat recovery units, burner management systems, selective catalytic reduction units (SCRs) and other clean-air and NOx reduction technologies.

OnQuest's principal offices are in San Dimas, Calif., and Calgary, Alberta; the company has sales and project offices in Houston, Tex., and San Francisco, Calif. OnQuest has sales representatives worldwide. OnQuest is a subsidiary of Primoris Services Corporation (NASDAQ: PRIM), one of the nation's largest specialty civil construction companies.