Abstract: The middle phase emulsion of a crude oil emulsion produced by a surfactant flooding of an oil reservoir is demulsified by contacting it with a water-soluble alkali metal hydroxide in an amount and under conditions sufficient to cause the hydrolysis of the middle phase emulsion and its subsequent separation into phases, wherein one of the phases is primarily an oil phase. The oil phase is then separated and, thereafter, can be further demulsified by demetalizing the oil by contacting it with a carboxylic acid or an amine salt of a carboxylic acid. It may be desirable to concurrently or subsequently treat the oil with an organic base, which can also be an amine demulsifier, to obtain a pH of from about 7 to about 9 in the final oil phase recovered from the acid demetalization step.

Abstract: Alkylbenzene sulfonate is added to a crude oil sulfonation product to prevent the formation of insoluble precipitates in the crude oil sulfonation product. The use of an alkylbenzene sulfonate as an additive to a microemulsion slug containing crude oil sulfonation product improves the injectivity of the microemulsion slug and prevents substantial plugging of the fluid injection system and the subterranean oil-bearing formation by insoluble precipitates in the microemulsion.

Abstract: Oil is recovered simultaneously from all phases of a surfactant-produced crude oil or simultaneously from the middle and upper phases of such an emulsion by acidizing the emulsion with a mineral acid, preferably nitric acid. Following the acidation step, the oil is rendered relatively noncorrosive by the use of a neutralization step which incorporates a demulsifier to prevent the reformation of subsequent emulsions. Polyalkyloxyamines are particularly useful as both neutralizers and demulsifiers. The process of the present invention is useful in the demulsification of crude oil emulsions produced by surfactant floods utilized in secondary and tertiary oil recovery techniques. The invention is particularly beneficial in the treatment of such emulsions produced by micellar or micellar-polymer flooding of oil reservoirs.

Abstract: A process for the demulsification of an emulsion comprising contacting the emulsion with a compound of the formula:R.sub.1 --(OA.sub.1).sub.p.sbsb.i OA.sub.2 N].sub.nwherein:R.sub.1 is selected from the group consisting of hydrogen, an alkyl, an aryl, an alkylaryl, a heterocyclic and N,N'diurea;--OA.sub.1 -- is an alkyleneoxy substituent;--OA.sub.2 N is a nitrogen-containing alkyleneoxy group;n is an interger having a value of at least 1 which denotes the number of --OA.sub.1 OA.sub.2 N groups attached to R.sub.1 ;p is 0 or an interger denoting the number of --OA.sub.1 -- units in each of the n groups attached to R.sub.1 ; andi is a subscript which distinguishes between the individual p group or each of the n groups.

Abstract: Nitriles are produced from carboxylic acids and ammonia utilizing an intermediate nitrogenous base-carboxylic acid complex by reacting said complex with ammonia at a temperature of from about 200.degree. to about 800.degree.C. The nitrogenous base is de-complexed as the nitriles are produced, recovered and recycled.