The solubility of fluorite in HCl and HF solutions with a variable concentration of Zr at 90, 155, 205 and 255 ᵒC and the pressure of saturated water vapor were investigated. The results showed that the solubility of fluorite increases with increasing concentration of zirconium. Using the OptimA program, the free energies of the ZrF62– complex were determined from the experimental data, from which the dissociation constants of the reaction ZrF62– =Zr4+ + 6F- were calculated. The pK values were 29,86±0,13; 34,03±0,062; 38,28±0,033; 40,94± 0,079 at 90, 155, 205 and 255 ᵒС (saturated water vapor pressure).
Researchers' views on the causes of mud volcanism have evolved over time. In the early stages, mud volcanoes were considered common to volcanoes. Later, they began to be associated with processes in sedimentary basins, although attempts to link mud volcanism with magmatic manifestations and replenishment of juvenile components still exist. Findings of mercury, native gold, silver, sulfur, copper, iron and accessory minerals in the products of mud volcanoes in recent years allow a number of researchers to assume the existence of deep-seated flows of hydrocarbons from the mantle, and to consider mud volcanoes as a kind of degassing pipes. The results of the analysis of trace element composition of mud volcanoes sediments in different regions of the world (Kerch Peninsula, North-West Caucasus, Sakhalin, Dzhungar Basin, Andaman Islands, Cadiz Bay, Eastern Mediterranean and Eastern Java) confirm the idea that in them, as in the mud volcanoes fluids (water, methane, carbon dioxide, and helium), traces of the mantle/juvenile component are not observed.
The results of experimental studies of the macro- and microcomponent composition of pore solutions of bituminous clay-siliceous rocks of the Bazhenov Formation (BS) of Western Siberia, containing up to 12.63% Corg ("normal rocks"), as well as silt-sandstones from the "anomalous" section are presented. BS with a Corg content of up to 0.63% ("abnormal" rocks) obtained on the basis of a study of aqueous extracts from core samples. It has been established that pore solutions of "normal" BS rocks have a sulfate-bicarbonate-sodium composition, and "abnormal" ones have a hydrocarbonate-sodium chloride composition. In pore solutions of both "normal and" abnormal "rocks relative to ocean water, the following were noted: a) concentration of Mn, Co, Ni, Cu, Zn, Mo, Sb, Cd, Ba, V, Cr of various degrees of intensity; b) increased content of Cs, Pb, Ti only in pore solutions of "abnormal" rocks; c) reduced content of Li, B, Rb, Sr. A direct relationship was found between the contents of Li, B, Ba, Sr, U, Mo, Cd, Sb, and Ni with the content in the Corg rock. For V, Cs, Sb, Rb, Ti, Mn in pore waters, the relationship with the amount of Corg in the rocks is close to the inverse relationship. In the pore solutions of "normal" BS rocks, the Ba content is equal to or higher than the Sr content, which is anomalous with respect to the stratal waters of most oil fields and ocean water and, apparently, is associated with the peculiarities of the accumulation of organic clay deposits, since in "anomalous" rocks The BS content of Sr is two times higher than the Ba content, which is closer to the usual for most natural waters.
Equilibrium mineral assemblages at temperatures from 50 °C to 350 °C and pressure of saturated water vapor were established by the thermodynamic modeling of hydrothermal reaction on the Bazhenov Formation rocks. The calculation results show that the mineral parageneses vary slightly with the temperature increase: for zeolites stilbite-laumontite-wairakite row is typical, kaolinite is replaced by montmorillonite and/or albite, pyrite — by pyrrhotite, calcite — by dolomite, brannerite — by uraninite. The simulation results are confirmed by experimental data.
Content of dissolved fluorides in the waters of 13 mud volcanoes of the Kerch-Taman region was determined: 0,13–2,00 mg/l with average value of 0,87 mg/l (n = 37). A fairly close correlation was established between the fluorine concentration and pH value (r = 0.80) in the absence of correlation with mineralization and content of components of the basic salt composition. It was suggested that the fluorine concentration in mud-volcano waters is controlled by the exchange reaction where et is content of adsorbed and structural fluorine (hydroxyl ions) in the clay minerals; F– et OH– is concentration of fluorides (hydroxyl ions) in the aqueous phase.
Volcano Girvas is a complexly constructed volcano complex of the Yatuli age. Apparently, it is a shield lava volcano, which was probably one of the supply channels of the vast lava field of the western Prionezhie region within the Girvas volcanic zone. Despite the fact that the Girvassky volcano is bare only fragmentary, the structure of the current is perfectly preserved in the rocks, allowing to reconstruct the direction of flow. Among these rocks, there is a zone of postvolcanic hydrothermal changes in the rocks, consisting mainly of nesting and veined tourmalization and silicification, as well as subsequent epidotization, sulfidization, chloritization and albitization. The zones of secondary changes are confined to faults, while their spatial-temporal correlation remains unclear. Reconstruction of the geological structure showed that there were two main processes at the Girvasa volcano: 1) pneumatolysis of type due to magmatic gases separated from gabbro-dolerite sills, 2) heating and circulation of exogenous waters with formation of near propylites. Based on the proposed scheme, thermodynamic modeling was performed.
The method of sample decompounding and silver sulfide precipitation for determination of the isotopic composition of sulfur by isotope mass spectrometry has been tried out and improved. The analytics and methodology of preparing test samples for analysis are described, task variations are indicated. The validity of the developed method of sample preparation was verified by a comparative analysis of various methods in three laboratories using internationally certified standards.
The experimental results on the synthetic oil production from Domanik Formation rocks under hydrothermal conditions are given. Oil fractions extracting potential of the rocks under hydrothermal was shown to be up to 60 mg/g or 6,0 wt.%. Inorganic additives (sodium carbonate or silica) incorporation does not influence on the oil recovery factor. Meanwhile the amount of recoverable oil products depends on the mineral composition of the rock. The dependence between the percentage of hydrocarbons emission and mineral composition of the rocks was determined. Clay minerals and silica increase the yield of synthetic oil, carbonates, conversely, inhibit the process.
Sorption properties of the soil layer at the base of the ash disposal site of the Sakhalin GRES-2 at the design stage of the facility were determined. Water extracts of the ash from the coal that will be used at the facility were analyzed to identify the potential elements-pollutants able to migrate with atmospheric precipitation through the soil. The model solution was developed based on these data. The soil sorption capacity in relation to the identified pollutants and the level of their potential desorption have been determined in static and dynamic conditions.
In this paper the temperature treatment impact on Bazhenov formation core samples are shown. Impact was performed by pyrolysis in a temperature range of 300-480 °C and in the closed autoclave in the presence of water at reservoir pressure. It is shown that as a result of thermal exposure at 400 °C pyrolytic peak S2 is reduced by 90-95% and generation potential of rocks almost completely implemented. The microtomographic samples studies combined with scanning electron microscopy allowed to establish the dependence of permeability and porosity of the rocks. It demonstrated that even at 350 °C the fracture system formed in core samples also the porosity and permeability due to impact may increase from several times to several ten times. The results will allow for a more accurate simulation of enhanced oil recovery treatment on Bazhenov formation rocks to increase oil recovery.
A methodic of destruction of objects with hardly dissolvable matrix (earth materials, tableted medical products) for subsequent determination of microelements by high-resolution mass- spectrometry with inductively coupled plasma is developed. Analytical and methodical problems, appearing during of a sample collection and preparation at investigated objects, are described, the ways of their overcoming are proposed. The opportunity of carrying out of quantitative analysis of investigated objects after dissolution by means of using multielemental standard solutions is shown. Accuracy of a developed methodic of sample preparation was checked by analysis of standard samples of earth materials.
The distribution of lithium between aluminosilicate and alkali-alumina-fluoride salt melts in a granite system with the limiting contents of water and fluorine at temperatures of 700– 800° C and pressures of 10–50 MPa has been experimentally studied. It is shown that lithium is distributed in favor of the salt melt under all conditions. An increase in the water content in the system by more than 20 wt.% and a pressure from 10 to 50 MPa leads to a decrease in the partition coefficients of lithium between the salt and aluminosilicate melts by 2–4 times.
Various techniques have been tested (multi-acid microwave decomposition and sintering with soda) for preparing samples for the analysis of ICP-MS for samples with a complex matrix including an organic component for the subsequent determination of the microelement composition. For research, we used samples of bottom sediments: terrigenous clay (SDO-1), volcanic-terrigenous silt (SDO-2), calcareous silt (SDO-3), ferromanganese nodules (SDO-5), Baikal silt (BIL-1) and complex sediment sample of Baikal (BIL-2). The most effective sample preparation methods for the studied rock type are proposed.
The paper presents the results of the hydrothermal processes of organic matter transformation in the rocks of the Bazhenov Formation and the Domanik horizon laboratory modeling. Shortterm exposure of samples to high temperatures (350 C) and reservoir pressures (300 atm) in the presence of water made it possible to simulate the processes that could take place in the reservoir, and to transform kerogen up to 70% in the rocks initially containing immature kerogen or kerogen in the beginning of the oil window. It was found that the amount of liquid hydrocarbon compounds generated during cracking mainly linearly depends on the content of organic matter in the rocks, while the gas generation is described by a rate function. The mineral composition of rocks does not affect the size of the formed pores, but in some cases it controls the amount of formed hydrocarbon compounds and the composition of the liquid products. It is shown that the increase in the amount of carbonate material in the rocks inhibits oil and gas generation process, there are lower amounts of light components in the products, and some of hopanes are absent. At the same time, high concentrations of siliceous material in the rocks with low amount of other components and, probably, the presence of pyrite can stimulate the generation process, in some cases allowing an increase in the amount of produced "synthetic" oil and gas, to achieve a greater variety of reaction products. The results obtained in general make it possible to examine the processes of individual hydrocarbon compounds formation during hydrothermal processes, to identify catalysts and inhibitors of the generation mechanism, and also, from a practical point of view, to propose conditions for reservoirs stimulation and development of technologies for increasing oil production and generation of oil with a controlled composition in situ.
