Oil recovery method using alkali and alkylaryl sulfonate surfactants derived from broad distribution alpha-olefins

Abstract

An oil recovery process is disclosed which uses an alkali(s) and a particular class of alkylaryl sulfonate surfactants. The surfactants are derived from an alpha-olefin stream having a broad distribution of even carbon numbers ranging from 12 to 28 or more. The olefin stream is reacted with aromatic feedstock, such as benzene, toluene, xylene, ethylbenzene, or a mixture thereof to form alkylates, and then reacted with SO3 to form sulfonic acids. Alternatively, the surfactant can be formed by first reacting an alpha-olefin stream having a broad distribution of carbon numbers ranging from 12 to 28 or more with SO3 to form the olefin sulfonic acid that is subsequently used to alkylate an aromatic feedstock. The use of alkali(s) and broad distribution alpha-olefins sulfonate based surfactant has the improvements of requiring ultra-low surfactant concentrations and providing ultra-low interfacial tensions over a wide range of alkali concentrations with crude oils, especially waxy crude oil, having a broad distribution of carbon numbers.

Description

FIELD OF INVENTION [0001] The present invention is directed to enhanced oil recovery (EOR). More specifically, the present invention is directed to enhanced oil recovery of crude oil using a mixture of alkali(s) and alkylaryl sulfonate surfactant derived from broad distribution alpha-olefins. BACKGROUND OF THE INVENTION [0002] This invention is an improvement over U.S. Pat. No. 6,269,881 and much of the background material is drawn from this reference and all references included in U.S. Pat. No. 6,269,881 are included herein. [0003] Alkylaryl sulfonates with narrow distribution carbon chains have long been recognized as promising surfactants for EOR. They can be manufactured in fairly large quantities and can generate adequate phase behavior and low interfacial tensions (IFT) with oils under favorable conditions. However, pure alkylaryl sulfonates such as hexadecyl benzene sulfonate or those having a narrow distribution carbon chains, cannot generate adequate phase behavior and low ...

AI Technical Summary

Benefits of technology

[0006] This invention provides an improvement over the closest existing art described in U.S. Pat. No. 6,269,881 and also provides other benefits that are not obvious to the ordinary skilled artisan which arise from the inclusion of alkali(s) with the surfactant derived from broad distribution alpha-olefins in the method of recovering oil from subterranean hydrocarbon containing formations and in the composition of enhanced oil recovery to displace said composition through the subterranean formation. The method is especially useful when the reservoir oil has higher wax content. The present invention includes a method of recovering crude oil from a subterranean hydrocarbon containing formation which comprises (a) injecting into said formation through an injection well an aqueous solution containing an effective amount of one or more alkali(s) along with an effective amount of alkylaryl sulfonate surfactant made by alkylating and sulfonating aromatic compounds and an alpha-olefin stream having a broad distribution in olefin carbon numbers, the olefin stream is the carbon chain C10 bottoms of a commercial ethylene synthesis alpha-olefin re

Problems solved by technology

However, pure alkylaryl sulfonates such as hexadecyl benzene sulfonate or those having a narrow distribution carbon chains, cannot generate adequate phase behavior and low interfacial tension with a wide range of crude oils especially when dealing with heavier crude oils, particularly those with a high wax content.

Furthermore, when used together with alkali in alkali surfactant flood, alkylaryl sulfonates with narrow distribution carbon chains are only effective over limited ranges of alkali

Images