Oil and Gas Production with Downhole Separation and Reinjection of Gas: 6,672,387

A system (SPARC) for producing a mixed gas-oil stream wherein gas is to be separated and compressed downhole in a turbine-driven compressor before the gas is injected into a subterranean formation. A turbine bypass valve allows all of the stream to bypass the turbine during start-up until surging in the production stream has subsided. The valve then opens to allow a portion of the stream to pass through the turbine. Also, a compressor recycle valve recycles the compressor output until the surging in the stream has subsided while a check valve prevents back flow into the outlet of the compressor.