Enticed by a grant offered by the state of California’s Energy Commission, Tideland Oil Production Co. of Southern California found a way to make good use of on-site gas and lower its utility bill at the same time. Tidelands recently installed a Waukesh Engine VHP P9390 GSI and pump package fueled by gas previously flared into the atmosphere. The package replaced an electric motordriven unit, but it was only after controls from Continental Controls Corp. were installed that the engine operated efficiently within the strict air quality limits. Air quality limits in California are among the most stringent found anywhere. The Waukesha VHP P9390 GSI engine emits below 1 ppm NOX and 12 ppm CO, well below half of the strict limits using a nonselective catalyst supplied by DCL International, designed for a rich-burn engine. The CO2 varies with the Btu of the gas, and the Continental fuel valve quickly increases or decreases the amount of fuel entering the carburetor allowing the engine to run within the tight limits so the exhaust oxygen level stays the same. The site uses GE/Fanuc controls, and the engine and pump were packaged by Pump Systems International, Houston, Texas, U.S.A.The recently completed project is unique for Tidelands in that the other water injection pumps on-site are driven by electric motors. The decision to use a natural gas engine-driven pump was prompted by two things: first, on-peak electrical power is very expensive in Southern California, but more important is the fact that the engine could perform within limits running on nonutility gas recovered on-site and associated with the oil production. The 2000 hp (1491 kW) natural gas-fueled engine drives a high-pressure centrifugal pump used to inject water into several old oil reservoirs. The pump boosts the water from 70 to 1800 psi (5 to 124 bar). The water is reinjected in order to force more oil out of the wells, thereby increasing oil production.