Kaveh Dehghani

Effects of CO2 Addition to Steam on Recovery of West Sak Crude Oil

This paper reports on a high-pressure 1D laboratory displacement study which evaluated the effects of adding CO{sub 2} to steam on the recovery of West Sak crude oil. Results of the laboratory experiments indicate that the simultaneous injection of CO{sub 2} and steam increases recovery, reduces injection temperatures, and reduces the heat input required.

Modeling Scale Up of Steamflood in a Heterogeneous Reservoir

A series of simulation runs was conducted for different geostatistically derived cross-sectional models to study the degree of heterogeneity required for proper modeling of steamfloods in a thick, heavy-oil reservoir with thin diatomite barriers Different methods for coarsening the most detailed models were applied, and performance predictions for the coarsened and detailed models compared. Use of a general scaleup method provided the most accurate coarse grid models.

Utilization of Associated Produced Gas to Improve Oil Recovery

Associated gas produced from oil fields in remote locations are costly to transport to market and if not utilized has been typically flared. Utilization of associated gas may justify some improved oil recovery processes (IOR), which would not be economic, if gas had to be purchased at world price. These IOR projects look especially more attractive if the available gas would otherwise be flared. Gas re-injection for pressure maintenance, and injection of gas enriched with LPGs at high pressures for miscible flood are among the practiced gas IOR processes. These methods are best applied to certain geologic settings, and operational parameters. Utilizing the associated produced gas as fuel to generate steam for IOR is an alternative method. In this paper, the overall criteria for applications of miscible gas floods and light oil steamflooding are compared and feasibility of steam injection process as a gas utilizing IOR method is examined. Application of steamflooding to three light oil reservoirs with different geologic settings is evaluated. These were a waterflooded vuggy dolomite, a deltaic sandstone structural trap with a gas cap, and a waterflooded deltaic sandstone. Optimization of steam injection to take advantage of individual reservoir characteristics is demonstrated. Steam injection process is also qualitatively compared with other stranded gas utilization methods such as liquefied natural gas (LNG), and chemical conversion of gas to liquid. The results show that light oil steamflood projects can be designed to take advantage of post-secondary residual oil saturation distribution in a considerably different fashion than conventional heavy oil steamfloods. The results also show that light oil steamflood when applicable is a potential for utilizing the remote associated gas.