Abstract
Preliminary results have indicated that hydroxyaluminum disoaps, particularly hydroxyaluminum di(2-ethyl hexanoate) and hydroxyaluminum di (mixed iso-octanoate), can increase the viscosity of propane, pentane and hexane when present in dilute concentrations. These compounds are insoluble in dense carbon dioxide at 293K. Although it is unlikely that these compounds can dissolve in pure methane, they may serve as effective thickneners for hydrocarbon miscible gas mixtures since a large amount of the light alkanes which can be thickened by these compounds is used to enrich the gas.
These disoaps can form extremely high molecular weight, rodlike micelles in solution which increase solution viscosity by several orders of magnitude. These thickeners are water insoluble, and slightly soluble in a North Slope crude oil. Therefore, the partitioning of a small amount of the disoap into the crude oil should not result in a significant loss of mobility control.
Light alkane- and carbon dioxide-miscible cosolvents, such as carboxylic acids or alcohols, can be used in dilute concentration to increase the solubility of these compounds in light alkanes while greatly reducing the time required to achieve dissolution. Most cosolvents will decrease the solution viscosity, but increase the stability of the solution. The capability of various cosolvents to enhance the solubility of these thickeners in dense carbon dioxide is currently being evaluated.
