Steam generation with carbon dioxide recycle

Abstract

Systems and methods relate to recovering hydrocarbons by injecting into a reservoir steam along with carbon dioxide recovered from flue gases produced while generating the steam and from separation of produced fluids. Due to benefits from the carbon dioxide injection, carbon dioxide capture rates from the flue gases selected below fifty percent in such combined recovery of the carbon dioxide enables lower fuel consumption even given that additional fuel is needed for the carbon dioxide capture versus steam only operations. As the capture rates from the flue gases increase above fifty percent like when employed for sequestration purposes, such approaches use more fuel than the steam only operations and may not be cost efficient. A carbon dioxide recovery unit coupled to an air-fired boiler or an auxiliary oxy-fired boiler may supply the carbon dioxide recovered from the flue gases.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a non-provisional application which claims benefit under 35 USC §119(e) to U.S. Provisional Application Ser. No. 61 / 862,309 filed Aug. 5, 2013, entitled “STEAM GENERATION WITH CARBON DIOXIDE RECYCLE,” which is incorporated herein in its entirety.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH[0002]NoneFIELD OF THE INVENTION[0003]Embodiments of the invention relate to methods and systems of producing a fluid of steam and carbon dioxide for injection into a reservoir to facilitate oil recovery.BACKGROUND OF THE INVENTION[0004]Enhanced oil recovery processes employ thermal methods to improve recovery of heavy oils from subsurface reservoirs. For example, injection of steam into heavy oil bearing formations heats the oil in the reservoir, which reduces the viscosity of the oil and allows the oil to flow to a collection well. A mixture of the oil and produced water that flows to the collection well is recovered to the surf...

AI Technical Summary

Benefits of technology

The patent describes a method and system for recovering hydrocarbons from a formation using steam and carbon dioxide. The process involves generating the steam through combustion, injecting it into the formation with carbon dioxide, and producing a mixture of hydrocarbons, steam, and carbon dioxide from the formation. The carbon dioxide is captured from the exhaust and serves to sustain the injecting process. The technical effect is a more efficient and effective method for recovering oil from difficult-to-reach formations.

Problems solved by technology

However, the DSG can only provide a narrow range of carbon dioxide concentrations and other ranges may be more effective.

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