Shale samples

In the mercury pump technique, the volume of a 25-g sample of shale is obtained by pressuring a chamber to 24 psig with and without the shale sample. In the mtid balance technique, shale cuttings are added in the mud balance cup until they weigh the equivalent of a cup of water. The volume of shale can be expressed as... 

The microsol scale technique is used to weigh a shale sample out of and in water, thus giving weight and volume. The results are plotted versus depth. Low shale densities (high porosity filled with water) indicate overpressured zone. A demonstration example is shown in Figure 4-336. 

The highest surface activity of fraction A3 extracted from shale oil needs to be explored in detail in order to understand this very unique phenomena. The benchmark experiments performed by Lee et al. (22) in studies of dissociation phenomena of Stuart oil shale in an alkaline environment proved the formation of carboxylic acids as it was verified from GC results. In another study by Lee et al. (23), it was shown that the hydroxyl ions from an alkaline solution could decompose the silicate and aluminasilicate structures in oil shale samples, provided that ultrasonic radiation and electrolytic current were simultaneously applied. 

A hypothetical structural model developed by Yen (24) represented the organic components of Green River oil shale. The major components were isoprenoids, steroids, terpenoids and cartenoids. The common bridges consisted of disulfide, ether, ester, heterocyclic and alkadiene. Elemental analysis of typical oil shale samples has shown... 

Hagiwara (2000) completed a reconnaissance survey of Se isotope variation in marine sediments and sedimentary rocks (Table 4). The most important observation was a lack of strong enrichment in lighter isotopes in most shale samples and three Black Sea sediments. It appears that near-surface alteration has altered Se isotope ratios in some cases. All of the Phosphoria formation samples were probably altered by deep groundwater or hydrothermal... 

As seen in Figure 6, mean 8 Mo in these ancient sediments is significantly offset from that of modem seawater and from mean 8 Mo of recent euxinic sediments. The offset is in the direction of less fractionation of Mo isotopes in the oceans (closer to the likely 5 MOjj ), as would be expected if removal of Mo to euxinic sediments expanded at the expense of removal to oxic (and suboxic) sediments. The result is consistent with the hypothesis of expanded ocean anoxia, and consequent increase in the areal extent of euxinic depositional settings, during this time. A similar, albeit smaller, offset is seen in repeated measurements of a Devonian black shale sample (USGS SDO-1 Fig. 6). This shift could he interpreted as consistent with somewhat expanded euxinic deposition during this time—an interpretation consistent with other evidence of expanded Paleozoic ocean anoxia in inland hasins. While further work is needed, these initial results are promising. 

Rosebery Hanging-wall Shale samples were selected from drill core in proximal (<120m from ore), medial ( 1000m) and distal (>4km) locations. 

Preliminary results indicate that base and precious metal, As, and Ba contents of shale in proximal and medial locations are within the range of shale samples from distal locations. Only Sb, up to 23 ppm, and Tl, up to 9 ppm, in the lower 10-15m of the hanging wall shale are significantly higher than in medial and distal samples, with <8 ppm Sb and <1.4 ppm Tl. 

Our current estimate for the quantitative mineral composition of the entire oil shale sample based on all 10 clusters Is presented In Table VII. These estimates are consistent with the qualitative XRD results of Table I. Because they are subject to several sources of uncertainty, It Is Impractical to assign error bounds at this time. These Include uncertainty In values of chemical elements for test vectors, problems In Identifying minor mineral components In the clusters, uncertainty In the relative concentrations of each element, and uncertainty In the organic content of each sample. 

Table VII. Quantitative Estimates of Percent Mineral Components in Mineral Matter of Oil Shale Sample ...

Fruchier rial. (1980), determined by X-ray fluorescence IXRF), except Aland Naby ncuiran activation analysis (NA At. Mg by flame atomic absorption tlidnum borate fusion (FAA), and B by plasma emission spectroscopy (sodium carbonate fusion) (PE5) Saether (1980), determined by XRF after low-temperature ashing (LTA) of raw oil shale samples In = 10). 

Figure 10. Percentage of initial concentrations of tracers left in solution as a function of time for the sorption experiments with the shale samples. ( X...

In most of the runs, the shale sample (as pebbles) was contained in a stainless steel, wire screen basket, 1/4-3/8 in. in diameter and 3 in. high. The reactor section was brought to the desired initial temperature with a stabilized gas flow stream at about 10 standard cu ft/hr. The sample was lowered into the reactor, and the power to the heating elements was adjusted to achieve the desired heat-up rate. The heat-up rates used included slow (about 15°F/min), fast (about 35°F/min), and very rapid, in which case the sample was lowered quickly into a preheated... 

After selection, the shale rocks were crushed, sieved, and divided into small samples by riffling. The shale samples weighed 2.5-3 g and were —6+10 U.S. Standard sieve size. The average composition of random samples chosen for chemical analysis is given in Table I. 

Soaking the shale sample for 1 hr or more at 700° or 800°F (or very slow heat-up) improves kerogen conversion at higher temperatures. 

The X-ray method affords a reasonable estimate of the structural formula based on chemical data. Using X-ray data, Ball calculated the structural formulas for twenty-six weathered soil and vein clay chlorites from North Wales. Tetrahedral Al ranged from 1.0 to 1.7 which is similar to the values for chlorites in shales. Octahedral Fe ranged from 0.8 to 2.4, with all but two values being less than 1.6 these values are much lower than those calculated (X-ray) for shale samples but almost identical to the shale values based on chemical determination of the Fe content. 

Figure 8. Carbon number distribution patterns (C15-C4q) of the midchain 2,5-dialkylthiophenes of the Jurf ed Darawish oil shale samples indicated.

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. 

Table I. Characteristic of Two Monterey Formation Shale Samples Used in the Pyrolysis Experiments...

Figure 2.2 BET plot for adsorption of N2 on shale samples at -195°C. Linear data array indicate conformity to Equation (2.11), by which indicated specific surface areas were calculated. Reproduced from Fanale and Camion (1971).

Crude oil analysis techniques, developed by the Bureau of Mines (9), was used initially to describe the overall quality of the product. Spent shale samples were ashed using a two-day, low temperature procedure. The covered samples were placed in a room temperature furnace, and the temperature was increased to 700°C (370°C) in a near-reductive atmosphere. The sample was uncovered and the temperature was increased to 750°F (300°C) for one more day with air forced over the sample. This method has been suggested to cause the least changes to heat-sensitive mineral components of the shale (17). Actual experience has shown that the time for this procedure can be halved because of the porous nature of the spent shale and the small sample size. Results are presented as weight percent of the pre-retorted sample. 

Table II. Characteristics of Microwave-Produced Oil and Oil from the Modified Fischer Assay of Divided Oil Shale Samples...

Dolomite, quartz, and analcite were the major minerals found in our shale sample. Lesser amounts of calcite, albite, K-feldspars, K-clays, and mica-clays were observed as well as trace levels of siderite and either pyrite or marcasite. This mineralological composition is similar to that reported elsewhere for the Green River shales (3,4). 

From the areas of this Green River shale sample that were examined in detail using the slow rastering microprobe technique, we have chosen three for discussion. Area A was a dark band located near the 6000-/xm position in Figure 1. Area B was in the wide, lighter colored area located at 13,000 fim, and area G included a black, organic strip at 16,000... 

The Devonian shale sample generally had a darker appearance with fewer and less distinct bands than the Green River shale sample, and the organic matter appeared to be more evenly distributed over the 2.5-cm sample. Several areas of this sample were examined using the slow rastering microprobe techniques to determine the elemental distribution in this material. The observations made in two of the areas are presented below. 

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