Showing papers in "Clay science in 1976"

Organophilic pores as proposed primary migration media for hydrocarbons in argillaceous rocks

Abstract: A chemical model for the structure of the double layer in the presence of organic ions and molecules in the vicinity of clay surfaces is postulated. The validity of this model is examined in the light of known literature on the interaction between clay minerals and organic compounds. The probability of the penetration of organic ions and molecules into the inner Helmholtz layer is discussed. The effect of migrating water on the migration of hydrophilic and hydrophobic organic compounds through a rock is discussed. The rate of migration of organic compounds depends on their chemical nature as well as the nature of the rock. From the model on the stability of the double layer it may be concluded that amphipathic molecules (soaps) are carried with migrating water from pores where their surface density is low to pores where their surface density is high. There is a probability of a complete saturation of several of the pores with organic ions or polar molecules. Such a pore is defined as an "organo-pore" and is shown to be hydrocarbon permeable. Organo-pores may become the paths for primary migration of hydrocarbon in the argillaceous source rock. INTRODUCTION The physical and geological processes which are associated with the primary migration of oil from clay source rocks have been the subject of many investigations (see e.g., Chapman, 1972; Cordell, 1972; Johns and Shimoyama, 1972). In most studies the primary migration of the hydrocarbons was considered to be dependent on the dehydration stages of the clay minerals and on the hydrostatic liquid pressures associated with burial depth of sediment. Recently, Cordell (1973) pointed out that intergranular primary migration of oil grobules or droplets would be quite difficult in argillaceous source beds because of small average pore size and predominance of extremely small pores. Pore size analysis suggests that pore diameters in general are less than 50 A. According to Cordell the primary migration is associated with enhancement of hydrocarbon solubility. This may occur in the presence of "soaps" which may form micelles . Cordell himself points out a few facts which conflict with this proposal. The quantity of soap required for hydrocarbon solubilization is many times greater than that of the hydrocarbon.

Nickeliferous fuchsite in the quartz-magnesite rock from the setogawa group, japan

Abstract: A nickeliferous fuchsite occurs in the Setogawa group, Shizuoka Prefecture in association with quartz, magnesite and chromite. The fuchsite contains 5.49 percent Cr2O3 and 2.00 percent NiO, and consists of only 1M polytype with the following lattice parameters: a=5. 275(5) A, b=9.045(5) A, c=10. 291(5) A and ƒÀ=101.80(10)•‹.