Geothermal history

The variation in the TR with depth for three other natural maturity sequences (Mahakam Delta, Paris Basin, North Sea) is plotted with that for the Monterey Fm. in Figure 4. While the geothermal histories of these sequences are different, there is in each case a strong relationship between maximum temperature experienced by the sample and depth. Depth is therefore used here as a common maturity axis for comparative purposes. Each of these sequences show a slight but significant decrease in this ratio with increasing depth. The extent of the decrease is, however, less dramatic than that for the Monterey sequence due mainly to their lower initial organic sulfur contents. 

Oil accumulations can continue to undergo thermal evolution, depending on the depth of the reservoir and subsequent geothermal history. As noted in Section 4.5.2, oil becomes susceptible to thermal cracking at temperatures above 160-200 °C. For example, paraffinic-naphthenic oils (Fig. 4.22) are degraded to aromatic-naphthenic oils (with moderate S content, <1%), and aromatic-intermediate oils degrade to aromatic-asphaltic oils (with high S content, >1%). 

Fournier, R.O. (1981) Application of water geochemistry to geothermal exploration and reservoir engineering. In Ryback, L. and Muffler, L.J.P. (eds.). Geothermal Systems Principles and Case Histories. New York Wiley, pp. 109-143. 

The relevance of the remarks on sulfur content is that, for reasons explained above, it is usually a valid index of the salinity of the environments of deposition. It was remarked earlier that the Eastern and Interior provinces have experienced different temperature/pressure/time histories. It should be added that coals of the Rocky Mountain, Pacific and Alaskan provinces most probably experienced yet further sets of conditions of metamorphism a locally increased geothermal gradient that produced relatively high temperatures at relatively low depths of burial and hence at relatively low pressures of overburden. 

This paper evaluates the applicability of the modified precipitation rate equation in predicting the discharge duration of a calciting well compared to the observed utilization history and the results of the conservative method from direct deposition of excess calcite. Three wells in Mindanao Geothermal Production Field (MGPF) with documented output decline due to calcite deposition were studied, namely APOID, SP4D, and MD1D. 

Lee, S. Bacon, L. 2000. Operational history of the Ohaaki geothermal field, New Zealand. In Proceedings World Geothermal Congress 2000, Kyushu-Tohoku, Japan, 28 May-10 June 2000, 3211-3216. 

Beall, J. J. 1993. The history of injection recovery in the units 13 and 16 area of the Geysers Steamfield. Geothermal Resources Council Transactions, 17, 211-214. 

Benoit, D. 1992. A case history of injection through 1991 at Dixie Valley, Nevada. Geothermal Resources Council Transactions, 16, 611-620. 

It would appear that their frequence decreases in older rocks, especially the Paleozoic (Weaver, 1959). The assembled studies of Perry and Hower (1970), Dunoyer de Segonzac (1969), Muffler and White (1969), Browne and Ellis (1970), Weaver (1959), Weaver and Beck (1971), Burst (1959), van Moort (1971) and Iijima (1970) demonstrate that the conversion of montmorillonite to other minerals in sequences of deeply buried sedimentary rocks is independent of time or geologic age and appears to be a function of the geothermal gradient which the rocks have experienced. These studies indicate that fully expandable dioctahedral montmorillonite is not stable above 100°C at depths of two kilometers or more. The occurrence of these minerals in sedimentary rocks can be considered to be controlled by their orogenic history. 

Dempster TJ, Persano C (2006) Low-temperature thermochronology Resolving geotherm shapes or denudation histories. Geology 34 73-76... 

Coulson I. M., Villeneuve M. E., Dipple G. M., Duncan R. A., Russell J. K., and Mortensen J. K. (2002) Timescales of assembly and thermal history of a composite felsic pluton constraints from the Emerald Lake area, northern Canadian Cordillera, Yukon. J. Volcanol. Geotherm. Res. 114, 331-356. 

Dahymple G. B., Grove M., Lovera O. M., Harrison T. M., Hulen J. B., and Lanphere M. A. (1999) Age and thermal history of the Geysers plutonic complex (felsite unit), geysers geothermal field, California a Ar-40/Ar-39 and U-Pb study. Earth Planet. Set Lett 173, 285-298. 

Nakamura M. (1995b) Residence time and crystallization history of nickeliferous olivine phenocrysts from the northern Yatsugatake volcanoes, central Japan apphcation of a growth and diffusion model in the system Mg-Fe-Ni. J. Volcanol. Geotherm. Res. 66, 81 — 100. 

Quane S. L., Garcia M. O., Guillou H., and Hulsebosch T. P. (2000) Magmatic history of the east rift zone of Kilauea Volcano, Hawaii based on drill core from SOH 1. J. VolcanoL Geotherm. Res. 102, 319-338. 

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