Gas Injection and Fingering in Porous Media

An Overview of Oil Production Stages: Enhanced Oil Recovery Techniques and Nitrogen Injection

“…10) Nitrogen is harmless compared to other gas (not flammable) [22]. 11) Nitrogen vaporizes the lighter components of the crude oil and generates miscibility if the pressure is high enough [33]. 12) Nitrogen provides a gas drive where a significant portion of the reservoir volume is filled with low cost gases [16] such as CO 2 [26].…”

“…3) Viscous fingering results occur in poor vertical and horizontal sweep efficiencies (due to the fact that the displacing fluid is less viscous than oil) [38]. 4) Because of the density differences, solvents and drive gases may segregate and override the other reservoir fluids, causing what's known density fingering, which in turn decreases the vertical sweep in horizontal floods [33]. 5) Flue gas and nitrogen have only limited application as agents of a miscible displacement in deep and high pressure reservoirs.…”

“…However, even if the gas that one wishes to use as a miscible displacement agent is economically available; its use is not without problems. [33]. In other words, the main problems, that encounters EOR engineers during gas injection are Override/Density Fingering and Viscous fingering [33], [39], [40].…”

“…[33]. In other words, the main problems, that encounters EOR engineers during gas injection are Override/Density Fingering and Viscous fingering [33], [39], [40].…”

“…This phenomenon is usually referred to as viscous fingering because mobility is originally controlled by viscosity. Under field conditions, fingering may be dominated by the distribution of the heterogeneities of the porous formation and, therefore, one should simply refer to the phenomenon as fingering [33]. As M values become bigger, fingering becomes more apparent [38].…”