ISSN:
0001-1541
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Previous laboratory studies have demonstrated that the injection of small quantities of reverse-wetting agents during water displacement can increase oil recovery from unconsolidated porous media. Hexylamine is a suitable reverse-wetting agent. It has been found that the effectiveness of this treatment increases with the quantity of amine injected (slug volume and/or amine concentration in the slug), and that treatments sufficient to stimulate oil production at high water flow rates did not do so at low flow rates. It has been established that the stimulation of oil production by this technique is accomplished by transient adhesion-tension alterations, resulting in the spontaneous accumulation of oil into large continuous masses which are subsequently mobilized.The present investigation has attempted to investigate the effect of other variables thought to be important in this system in order to clarify the mechanism by which increased oil recovery is effected. Specifically, the mechanism by which large oil masses are formed and propagated was studied.Displacement studies conducted in a glass-grid micromodel, under cinemicrographic observation, revealed that large oil masses form as a consequence of restoration of water wettability (amine desorption) but only if the local oil saturation exceeds the irreducible minimum value (under water-wet conditions). Mobilization of these oil masses was observed under the influence of a favorable wettability gradient.Displacement studies were also performed in unconsolidated silica sand beds, under conditions of varying oil-water viscosity ratio, hydraulic permeability, flow rate, and time at which the amine was injected. In the range of the variables investigated, the additional oil recovered (by treatment) increased as the viscosity ratio increased oil recovery. Water-oil displacement efficiencies enhanced by amine treatment were found to correlate satisfactorily with a parameter representing the ratio of the hydraulic forces to the capillary forces within the medium.
Additional Material:
11 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/aic.690110412
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