Anomaly hydrocarbon

To detect surface anomalies caused by hydrocarbon accumulations often very small amounts of petroleum compounds have leaked into the overlying strata and to the surface. On land, these compounds, mostly gases, may be detectable in soil samples. 

Hydrocarbon Anomalies in Soils Soil samples were collected at 200 to 500 meter intervals over the Lisbon and Lightning Draw fields and analyzed for thermally desorbed C1 to C12 alkanes by GC-FID and solvent-extractable C6 to C36 aromatics by fluorescence... 

Aromatic hydrocarbon anomalies are evident in soils over both fields (Fig. 2). The anomalous 4-, 5-, and 6-ring aromatic hydrocarbons, which correspond with... 

The main conclusion drawn from this study is that hydrocarbon- and fixed gas-based geochemical exploration methods in the Paradox Basin are cost-effective tools for pre-screening large areas to focus subsequent lease acquisition and seismic surveys for oil and gas exploration. Heavy metal anomalies are more difficult to link with the reservoir. 

Interesting results are obtained if 160 kg/h is deducted from the measured hydrocarbon flow for coil 2, and 210 kg/h added to the hydrocarbon flow for coil 3. The anomaly between the coil heat transfer coefficients for coils 2 and 3 has disappeared. Figure 7 shows the effect that the adjustment to the coil flow has on the crossover... 

Furthermore, it has been noted that when the rate of the oxygen atom-olelin reaction and the rate of the ozone-olefin reaction are totaled, they do not give the complete hydrocarbon consumption. This anomaly is also an indication of an additional process. 

S3omyaev, Z.I., Tnmanyan, B.P., Kolesnikov, S.I., and Zhokhova, N.l. Some anomalies in melUng points of binary mrxtnres of solid hydrocarbons, Zhur. Prlkl. Khlm. (Leningrad), 57 666-669, 1984. 

Aromatic hydrocarbon anomalies are evident in soils over both fields (Fig. 2). The anomalous 4-, 5-, and 6-ring aromatic hydrocarbons, which correspond with the 395 nm, 431 nm and 470 nm fluorescence peaks suggest the presence of heavy oil seeps at surface. Light alkanes (ethane and n-butane) are the most important... 

Carbonaceous material (Fig. 12.8b) is intimately mixed with silicates and is very abundant (carbon abundance averages 13% and varies up to 50%) in CP IDPs. Some carbon is elemental (graphite), but C-H stretching resonances in infrared spectra show that aliphatic hydrocarbons are also present. Polycyclic aromatic hydrocarbons (PAHs) also occur. Nanodiamonds have been identified in cluster IDPs, but not in smaller CP IDPs. Enormous D/H and 15N/14N anomalies have been measured in bulk IDPs, and the hydrogen isotopic anomalies are correlated with organic-rich domains. Ratios of D/H as high as 25 times the solar ratio suggest the presence of molecular cloud materials. 

However, there are certain anomalies with respect to the alkyl mechanism, namely, the relatively small amounts of C2 hydrocarbons in the Anderson-... 

Seismic Data Processing. Continuing advances in technology, such as fiber optics, have enabled the capabilities of seismic surveys to be markedly increased so that, where required, a 3-dimensional picture of the rocks in the subsurface can be obtained. Advanced processing has also enabled discrete anomalies in seismic data from individual rock horizons to be analyzed. Under certain conditions, the presence of hydrocarbons can be directly detected. This analysis, sometimes referred to as bright spot technology, has been responsible for numerous discoveries in the Gulf of Mexico in recent years. 

However, it is difficult to reconcile the observed relative reactivities of hydrocarbons with a mechanism involving electron transfer as the rate-determining process. For example, n-butane is more reactive than isobutane despite its higher ionization potential (see Table VII). Similarly, cyclohexane undergoes facile oxidation by Co(III) acetate under conditions in which benzene, which has a significantly lower ionization potential (Table VII), is completely inert. Perhaps the answer to these apparent anomalies is to be found in the reversibility of the electron transfer step. Thus, k-j may be much larger than k2 for substrates, such as benzene, that cannot form a stable radical by proton loss from the radical cation [Eqs. (224) and (225)]. With alkanes and alkyl-substituted arenes, on the other hand, proton loss in Eq. (225) is expected to be fast. 

Finally, it should be noted that the rate of oxidation of cyclohexane by Co(III) trifluoroacetate in TFA was less than 10% that of benzene.185 This comparison contrasts sharply with the much faster rate of reaction of cyclohexane with Co(III) acetate in acetic acid (see p. 324). Obviously more work is required to explain such apparent anomalies and to elucidate the mode of interaction of Co(III) with saturated hydrocarbons. 

These suggestions are supported by the fact that nitromethane/ aluminium chloride1 can be used for anodic voltammetry of aromatic hydrocarbons (Bauer and Foucault, 1972) without any anomalies being found with respect to the scale of potentials as compared to more normal SSEs (Table 7). Also, acetonitrile/... 

In THF, the alkyllithium compounds are aggregated [157] and the situation is reminiscent of the conditions in hydrocarbon solutions. At high concentrations, the association number (i. e. the number of molecules in the aggregate) decreases. This anomaly is explained by the existence of aggregate—solvent complexes, for example (MeLi)4 8THF Benzyllithium and its polymeric analogue polystyryllithium are not associated. Phenyllithium is mostly present as a dimer or monomer. Both forms are in equilibrium and are solvated. Only the monomeric form of the initiator is active. In practice, benzyllithium reacts only in the form of an ion pair. The fraction of the free benzyl anion must be very small [151c]. 

The fact that the benzene ring contains three double bonds suggests that the members of this series should be very reactive. However, this is not so, and although they are not as stable as the parafSns, they do not show the high reactivity that is so characteristic of the olefins. The reason for this apparent anomaly has troubled chemists for over a half century and it has not been until the relatively recent application of quantum mechanical concepts that this problem has been satisfactorily answered. However, a thorough discussion of the problem is beyond the scope of this book and the student is asked to accept the stability of benzene without a simple explanation for this fact. Compounds of this series do occur in crude oil. Indeed, petroleum is one of the important sources of these very important hydrocarbons. 

Early investigators assumed that hydrocarbons would migrate vertically, and any resulting surface anomaly would be directly over the location of the trap. This concept has changed considerably over the years, and it is now known that a number of factors may affect the location of any surface... 

Only in the lithium catalysed copolymerization of styrene with the dienes in hydrocarbons do the monomers show an unexpected order of reactivity, an anomaly which disappears for polar solvents. The preference for the diene in the copolymer vanishes even in hydrocarbon solvents if sodium is used as initiator [231]. With the dienes, however, an added complication exists which makes simple experiments on electron affinity measured in solvents such as dioxane—water a poor guide to reactivity. They can react in more than one way to give a 3,4 (or 1,2) structure or alternatively a 1,4 structure. There appears to be good correlation between the amount of styrene in the copolymer and the percentage of... 

Many of the significant reactions of unsaturated hydrocarbons (hydrogenation, isomerization, carbonylation, oxidation, polymerization) are catalyzed heterogeneously by metals in or near Group VIII or homogeneously by salts and complexes of these elements. Those reactions effected in both systems are discussed in terms of probable common intermediates anomalies, where they occur, are ascribed either to the ability of surfaces to form intermediate species which cannot be stabilized by single metal atoms or to the ability of the latter to coordinate simultaneously more than one hydrocarbon molecule. 

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