Bear Rock Formation

This equation defines the permeability (K) and is known as Darcy s law. The most common unit for the permeability is the darcy, which is defined as the flow rate in cm3/s that results when a pressure drop of 1 atm is applied to a porous medium that is 1 cm2 in cross-sectional area and 1 cm long, for a fluid with viscosity of 1 cP. It should be evident that the dimensions of the darcy are L2, and the conversion factors are (approximately) 10 x cm2/darcy C5 10-11 ft2/darcy. The flow properties of tight, crude oil bearing, rock formations are often described in permeability units of millidarcies. 

Temperature, humidity, precipitation, and evaporation are important factors that contribute to the oxidation of sulfide minerals. In warm and wet climates, excessive precipitation may produce persistently high water tables and extensive biological activity that may create reducing conditions in the shallow subsurface and hinder sulfide oxidation (Seal et al., 2002, 208). At the surface, high humidity and temperatures would promote the oxidation of sulfide minerals (Williams, 2001, 274). Frequent precipitation would also suppress evaporation and the formation of arsenic salt deposits (Seal et al., 2002, 208). Furthermore, precipitation and groundwater, which are controlled by climate, are the major sources of water for the production of arsenic-contaminated runoff from sulfide-bearing rock outcrops. 

Water washing of the formation is also capable of causing alterations in the sulfide distribution by differential removal of the more water soluble, lower MW and shorter chain members, Figure 15. This effect is probably the most striking manifestation of the water washing history of the oil-bearing rock and oil sand formations. 

In certain situations, FE could prove useful in the remote detection of fracture. An unusual radio emission observed at several widely space receivers six days before the Great Chilean Earthquake of May 22,1960, has led Warwick, Stoker, and Meyer to speculate that stress induced microfracture along the Chilean fault was the source of this emission (38). More recent observations of RE some hours to tens of minutes before earthquakes have been made by Soviet researchers (39). Nitsan has surveyed a number of minerals for fracture related RE and has concluded that quartz-bearing rocks were sources of rather intense RE (IS). Under similar conditions, rocks not containing quartz (basalts, obsidians, limestones) did not yield detectable RE. Therefore, RE is expected to be a strong function of the mineral content (quart or non-quartz bearing formations). Formation structure (the presence of previously pulverized material, state of stress and strain) is also expect to affect RE intensity. 

Snezko, A.M. and Berezovskiy, F.I., 1975. The nature of the graphite-bearing rocks of the Krivoy Rog group. Doklady Akad. Nauk S.S.S.R. (Rep. Acad. Sci. U.S.S.R.), 222(1) 197-200 (in Russian). Sobolev, V.S., 1961. On pressure in metamorphic processes. In Fiziko-khimicheskiye problemy formiro-vaniya gornykh porod i rud (Physicochemical Problems of the Formation of Rocks and Ores), Izd. Akad. Nauk S.S.S.R., Moscow, 1 7-16 (in Russian). 

Another, less well-documented occurrence of celadonite is the subaerial alteration of basic and basaltic rocks. Here interaction of surface waters promotes the formation of celadonite, a similar process to that of hydrothermal alteration but at a lower temperature. In both cases there is significant oxidation of the initial iron-bearing rocks. This is reflected in the high ferric iron content of the celadonite minerals. 

Flint Clay parting in the Hazard No. 4 (Fire Clay) coal bed of the Breathitt Formation in Eastern Kentucky Guidebook, Geol. Soc. Am. Annual Meeting, Coal Div. Field trip. Coal and Coal-Bearing Rocks of Eastern Kentucky, Kentucky Geol. Survey, p. 49-54. 

Polastro RM (1985) Mineralogical and morphological evidence for the formation of illite at the expense of illite-smectite. Clays and Clay Minerals 33 265-274 Polastro RM (1993) Considerations and applications of the illite/smectite geothermometer in hydrocarbon bearing rocks of Miocene to Mississippian age. Clays and Clay Miner 41 119-133... 

FIGURE 17.14. In petroleum recovery processes an aqueous displacing fluid may be used to force crude oil from a rock formation. Optimum results will usually be expected if the displacing fluid effectively wets the petroleum bearing rock (a). If good wetting is not obtained, petroleum may remain trapped in the rock structure never to be recovered (Z>). 

Obviously, no optimal EOR polymer currently exists. It is difficult for one single polymer to meet all of the requirements. This situation is caused by the various physical conditions (e.g. salinity, temperature, porosity, clay, rock formation, etc.) which the polymer is subjected to in the underground formations. Therefore, it is necessary to choose a synthetic polymer which exhibits the desired behavior for the specific oil bearing formation. Section 2 deals with the characteristic molecular parameters of a polymer sample e.g. M, M /Mn, size and shape, as well as with the phenomenon of aging. The viscosity maxima behavior of partially hydrolysed PAAm (c.f. Section 2) has been noted. Samples with 67 mole t acrylic acid attain maximal viscosity at a minimal My. ... 

---