Primary migration, of hydrocarbons

Micelles appear to be larger than the small size of the pore throats in the source rock at a depth of burial corresponding to the main zone of oil and gas generation. According to Tissot and Welte (1984), primary migration of hydrocarbons in micellar solution would definitely be limited down to a depth of about 2000 m. 

After primary migration has taken place, a certain proportion of the generated hydrocarbons remains in the pore system of the source rock (Hunt, 1979). The oil fraction that remains in the source rock will be cracked to gas as the source rock is buried to greater depths and temperatures (Section 3.1.5). The effect of primary migration of hydrocarbons can be indicated by the expulsion efficiency. The petroleum expulsion efficiency is the ratio of the expelled petroleum and the sum of the generated and initial petroleum and can vary from zero (no expulsion) to 1.0 (complete expulsion) (Cooles et al., 1986). The expulsion efficiencies are not uniform in time and space (Leythaeuser et al. 1987b). They depend on the tsrpe of source rock, its richness and thermal maturity and the primary migration mechanism. 

Leythaeuser, D., Schaefer, R.G. and Yukler, A. 1982. Role of diffusion in primary migration of hydrocarbons. Am. Assoc. Pet. Geol. Bull., 66 408-129. 

Stainforth J.G., Reinders J.E.A. (1990) Primary migration of hydrocarbons by diffusion through organic matter networks, and its effect on oil and gas generation. Org. Geochem. 

Role of diffusion in primary migration of hydrocarbons. American Association of Petroleum Geologists Bulletin, 66, 408 29. 

One of the most important rules in the formation of hydrocarbon deposits has been demonstrated, based on the fact that the primary migration of hydrocarbons follows closely on the formation of the secondary porosity, as during maturation of the organic matter the main phase of formation of the hydrocarbons takes place after the culmination of the decarboxylation which generates active acid solutions controlling the formation of the secondary porosity. This shows that the generation of hydrocar-... 

The primary focus of this chapter is to introduce approaches that limit (or prevent) migration of hydrocarbon and organic contaminants from the vadose zone into underlying water-bearing zones. The more conventional strategies, including a brief discussion of the process, relative cost, practical constraints, and limitations, are presented. Also presented are two typical soil vapor extraction case histories. 

Talukdar S., Gallango O., Vallejos C., and Ruggiero A. (1987) Observations on the primary migration of oil in the La Luna source rocks of the Maracaibo Basin, Venezuela. In Migration of Hydrocarbons in Sedimentary Basins (ed. B. Doligez). Editions Technip, Paris, France, pp. 59-78. 

Lewan, M.D., 1987. Petrographic study of primary migration in the Woodford Shale and related rock units. In Doligez, B. (ed.), 1987. Migration of hydrocarbons in sedimentary basins. 3rd IFP Exploration and Production Research Conference, 1987. Editions Technip, Paris, pp. 113—130... 

Price, L.C. (1973) The Solubility of Hydrocarbons and Petroleum in Water. Ph.D. Thesis., University of California, Riverside, CA. Price, L.C. (1976) Aqueous solubility of petroleum as applied to its origin and primary migration. Am. Assoc. Petrol. Geol. Bull. 60, 213-244. 

Migration (primary) the movement of hydrocarbons (oil and natural gas) from mature, organic-rich source rocks to a point where the oil and gas can collect as droplets or as a continuous phase of liquid hydrocarbon. 

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