Maturity indicators/parameters

The transformations reviewed in Section 5.5 are potential maturity indicators.The most useful reactions are those in which only one of the pair of components is present initially in immature sediments, so that the extent of the transformation can be attributed entirely to thermal maturation (the kinetics of the transformation are also simpler Box 5.4). Such reactions include isomerization of pristane at C-6 and C-10, of steranes at C-20 and of hopanes at C-22, and also the aromati-zation of C-ring monoaromatic steroidal hydrocarbons. A number of molecular maturity parameters are shown in Fig. 5.47, together with some bulk maturity measurements.The correlation of values is approximate and varies with the type of organic matter present, its potential for generating petroleum and its heating rate. 

Determining the thermal maturity of light oils and condensates can be difficult. Biomarker concentrations in crude oils are low and biomarker maturity parameters have limited applicability at high levels of thermal maturity (Peters and Moldowan, 1993). Light hydrocarbons (C6-C7) are volatile, susceptible to biodegradation and maturity parameters derived from these compounds may be unreliable. In this chapter, we report on the correlation of C4-benzene and C4-naphthalene compounds with thermal maturity in oil cracking pyrolysis products of a Western Canada Sedimentary Basin (WCSB) oil. The use of C4-benzene and C4-naphthalene compound ratios as thermal maturity indicators in natural systems was evaluated using crude oils from the Fort Worth Basin, Texas, USA. 

Calculating an equivalent %Rq value for pyrolysis experiments based on experimental conditions is a convenient way to compare the level of thermal stress achieved in experiments performed at various temperatures and times and eliminates uncertainty in biomarker maturity indicators that arise during pyrolysis. In this way, the level of thermal stress achieved for an experiment performed at 360°C and 12 days can be easily compared with an experiment performed at 400°C and 1 day, for instance. The positive correlation between various C4-naphthalene and C4-benzene ratios with increased thermal stress (calculated %/ o) in the oil pyrolysis experiments motivated the evaluation of these ratios as maturity parameters in oils from the Fort Worth Basin. The Fort Worth Basin oils were analyzed as part of this study because the Barnett Shale is the only petroleum system in the basin and also because samples were readily available from various stratigraphic horizons. The TAS ratio is an accepted thermal maturity indicator for low API gravity oils (Mackenzie et al, 1981) and was used in this study to evaluate C4-naphthalene and C4-benzene as potential maturity indicators for high API gravity oils. Thus, correlation of C4-naphthalene or C4-benzene ratios with the TAS maturity ratio is viewed as a confirmation of the effectiveness of these parameters to estimate the thermal maturity of a light crude oil. 

C4-benzene ratios provide a method to determine the relative maturity of light oils and condensates. The range of usefiilness for C4-benzene parameters appears to extend beyond the thermal maturity limits for all the biomarker parameters. Provided the C4-benzene parameters can be calibrated to another maturity parameter that extends beyond TAS, such as vitrinite reflectance, the C4-benzenes hold great potential as a thermal maturity indicator. 

Qualitatively, all proposals indicate a linear dependence on ml (linewidth over a hyperfine pattern increases from low to high field or vice versa cf. Figure 9.4) plus a quadratic dependence on m, (outermost lines more broadened than inner lines). Multiple potential complications are associated with the lump parameters A, B, C, notably, their frequency dependence (Froncisz and Hyde 1980), partial correlation with g-strain (Hagen 1981), and low-symmetry effects (Hagen 1982a). The bottom line quantitative description of these types of spectra has been for quite some time, and still is, awaiting maturation. 

This chapter presents a comprehensive review of previous research on mead production. It will focus on honey characterization and mead production. The first section covers honey composition and the way this affects honey properties, as well as important parameters that are indicators of honey quality. The second section discusses mead production, including fermentative microorganisms, fermentation conditions, and required postfermentation adjustments and maturation conditions. The final section focuses on the problems that must be surpassed and what the future holds for mead production. 

For diagnostic purposes, relevant parameters are collected and logged into the control system in order to determine appropriate maintenance periods and its service timing. For example, noise and vibration can serve as indicators of the status of health for a polisher. Large pressure and temperature valuations may provide alarms for malfunctions or problems within fluid lines. Such techniques have been developed and implemented in other technical fields, such as power generation machinery. The adoption of these mature technologies significantly improves the uptime of CMP system. 

Reproductive success is certainly another measure of the health of an organism and is the principal indicator of the Darwinian fitness of an organism. In a laboratory situation it clearly is possible to measure fecundity and the success of offspring in their maturation. In nature these parameters may be very difficult to measure accurately. Many factors other than pollution can lead to poor reproductive success. Secondary effects, such as the impact of habitat loss on zooplankton populations essential for fry feeding, will be seen in the depression or elimination of the young age classes. 

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