Shale distribution type

Shale distribution type laminated, dispersed) There are different techniques to estimate shale distribution type Cores and images, Thomas-Stieber analysis (Thomas and Stieber, 1975), conductivity investigation of the formation by measurement of conductivity in an orthogonal axis system (see Section 8.6),... 

Figure 9. Comparison of Cl5 chemical group type distributions of expelled oil and retained bitumens for typical Type II (marine shale) and Type IIS (carbonate) source rocks (middle of the the oil window).

Permeability of shaly sands is controlled by shale/clay content, type of shale distribution (laminated, dispersed, stmctural), porosity, and confining stress. A general impression is given by Fig. 2.18. 

Based on studies on artificially composed materials (sand and clay), the Simandoux (1963) equation was derived. It represents a stmctural and dispersed type of shale distribution. The equation was modified by Bardon and Pied (1969) ... 

The primary difference in shale oils produced by different processing methods is in boiling point distribution. Rate of heating, as well as temperature level and duration of product exposure to high temperature, affect product type and yield (28). Gas combustion processes tend to yield slightly heavier hquid products because of combustion of the lighter, ie, naphtha, fractions. 

Barite [13462-86-7], natural barium sulfate, BaSO, commonly known as barytes, and sometimes as heavy spar, tiU, or cawk, occurs in many geological environments in sedimentary, igneous, and metamorphic rocks. Commercial deposits are of three types vein and cavity filling deposits residual deposits and bedded deposits. Most commercial sources are replacement deposits in limestone, dolomitic sandstone, and shales, or residual deposits caused by differential weathering that result in lumps of barite enclosed in clay. Barite is widely distributed and has minable deposits in many countries. 

Considerable geographic variability exists in the distribution of the source rocks contributing salts to river and groundwaters. As shown in Table 21.3, most of the evaporites, which are the dominant natural source of Na and Cl in river water, lie in marginal and endorheic (internal) seas. Some of these subsurfece evaporite deposits dissolve into groundwaters, which eventually carry Na and Cl into the ocean. Carbonates are the prevalent rock type between 15°N and 65°N. Precambrian-age crustal rocks and meta-morphic minerals predominate between 25°S and 15°N and north of 55°N. Shales and sandstones represent on average 16% of the terrestrial surfece lithology. 

Only the Big Horn coal liquids have more condensed cycloalkanes than noncondensed cycloalkanes. The tar sands have an equal distribution of the two types of saturates, and the remaining fuels have a higher concentration of noncondensed cycloalkanes. The effect of the olefins on the mass analysis of the saturates from the shale oils must, however, be kept in mind in making this comparison. 

Two Type II-S kerogens (as defined by Orr (i)) from the onshore Santa Maria Basin Monterey formation were pyrolyzed in this study to determine (a) the distribution of sulfur and its isotopic composition among the various products formed during artificial maturation, and (b) maturation trends reflected in the sulfur isotopic and elemental S/C ratios of kerogens, and in the variation of C and H isotopes. In addition, S isotopes in pyrites, kerogens and bitumens from the two Monterey shale samples were examined to speculate on the mode of S incorporation into Santa Maria Basin sediments. 

Figure 8 Observed cumulative mass/age distributions of major sedimentary lithological types. Explanation of abbreviations gr denotes graywackes sh, shales ark, arkoses ss, sandstones dol, dolostones evap, evapor-ites Im, limestones phosp, phosphorites CB, continental basement P, platforms MOB, mature erogenic belts OD, oceanic domain (after Veizer, 1988c).

Fig. 5.51 Kerogen transformation at a constant heating rate of3°CMyr 1, based on single A plus discrete Eact distributions (after Tegelaar Noble 1994) for tasmanites (type I, Cretaceous, North Slope, Alaska), Monterey shale (type II—S, Miocene, Ventura, California), Kimmeridge Clay (type II, Jurassic, North Sea) andManville Formation (type III, Cretaceous, Alberta). Modelled vitrinite reflectance based on EASY%Ro (after Sweeney Burnham 1990 Table 5.5).

A very important factor is the location and distribution of clay particles within the rock. The total clay content or clay type are not dependable indicators of the susceptibility of the rock to damage. The location of clays and the clay growth form tend to control the degree of damage susceptibility. A rock in which most of the clay is confined to shale streaks or mud rip up clasts is likely to be less susceptible to damage compared with the rock in which clay is present in the pore lining form. 

Dunn 1987), thus closely matching the values (—28.2 2.7, = 3) found by Elvsborg et al. (1985). The pristane/phytane ratio of extracts from this formation fall in the range of typical type II marine shales, e.g. 0.6-1.60 (Elvsborg et al. 1985 Cohen Dunn 1987) and with a uniform sterane distribution centring around C27 = 34%, Cjg = 33%, C29 = 33% (Cohen Dunn 1987). 

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