Secondary and Tertiary Recovery of Oil by MCCF Process
Authors: Sarem A.M. Sam 
Published: December 2007

This paper was prepared for the 44th Annual California Regional Meeting of the Society of Petroleum Engineers of AIME, to be held in San Francisco, Calif., April 4–5, 1974. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made.

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Mobility-Controlled Caustic Flooding (MCCF) is a process designed to improve oil recovery from either virgin or watered-out reservoirs by increasing the volumetric as well as the displacement efficiency of a waterflood. In this process alternate slugs of two very dilute solutions, first of a highly alkaline soluble silicate, and then of calcium chloride, separated by a water spacer, are injected into the reservoir.

Upon in-situ contact with some crude oils, the silicate produces a surfactant that improves the displacement and volumetric efficiencies. The calcium salt, when reacted with a portion of the alkaline silicate, produces a fine precipitate to reduce water mobility in precipitate to reduce water mobility in watered-out channels, causing water diversion.

Background

The addition of chemicals to flood water is not new. As stated by Scott, Fyleman patented a process using sodium carbonate for separating process using sodium carbonate for separating bitumen from sand as early as 1920, and Nutting suggested a similar method for improving waterflooding. Nutting's experimental waterfloods of Torpedo sandstone, using sodium hydroxide solutions, increased recovery by twenty percent as compared with brine floods. The percent as compared with brine floods. The increase in recovery was associated with the aqueous solution of silica portion of the system. Either adsorption or chemical reaction of the alkaline solution with silica was assumed to take place at the interface.

Dunning, et al. claimed that the surfactant produced by the reaction of crude oil with produced by the reaction of crude oil with sodium hydroxide displaced the interfacially active asphaltic aggregates responsible for the rigidity of the interface that inhibited effective oil displacement.

Dennekas, et al. explained that resins and surface-active material, in combination with long chain paraffins, form a hydrophobic film deposited on the sand grains. These materials were separated by adsorbing them on sucrose and by subsequently dissolving the sucrose in water and benzene.

In a series of experiments, Scott, et al. concluded that the interfacial tensions between crude oil and brine can be reduced considerably by both acid and alkaline solutions (solutions containing 0.005% NAOH reduced the interfacial tension of Lloydminster crude and brine below one dyne per centimeter).