Proceedings of Siberian Department of the Section of Earth Sciences of the Russian Academy of Natura

30-41

Authors: S.M. Radomskii, V.I. Radomskaya

The beginning development of the Malomyr gold deposit makes relevant the evaluation of the concentration of other noble metals (NM) in the ore samples from this deposit. The main purpose of the study is assessment of the concentrations of platinum metals in order to perform the complex extraction of useful components (Ru, Rh, Pd, Ag, Os, Ir, Pt, Au) from the mineral raw material.

57-68

Authors: A.K. Seminsky

The Purpose of the paper is to study the general patterns of emanations of radon dissolved in the underground waters of the Southern Baikal region, to identify the main factors affecting the emanations and to propose a method enabling the prediction of changes in radon concentration for a single water manifestation during a year based on a single sample selection. Methods. The radon content in each of the sources chosen for the study was measured 1 time every two weeks. The volume activity of radon (Q, Bq/l) was measured using a radiometer PPA-01M-03. In addition to the Q parameter, weather data on the days of sampling were recorded, as well as the data on seismic activity in the study area. Quantitative analysis was carried out using standard statistical methods (cluster, correlation and Fourier analyzes). Results. A monitoring network of eight sampling points was created. Underground waters of the investigated area are found to be non-radon (Q≤185 Bq/l). The studied water manifestations are divided into three groups according to the average radon content in water during the sampling period: 1st group – Q average ≈ 15 Bq/l, 2nd group – Q average ≈ 30 Bq/l and 3rd group – Q average ≈ 60 Bq/l. The radon content in water varies; ΔQ is 30-60% of the mean value in the test source. The Fourier analysis allowed to factorize the complex oscillations of the Q parameter into the simple harmonics: of the first order (the wavelength is about 365 days), of the second order (≈ 126 days) and of the third order (≈ 30 days). All the analyzed values are divided into three main clusters according to their degree of mutual dependence. The first is Q parameters for different sources, the second and third are various factors of emanation field formation: external (meteorological conditions) and internal (earthquakes of different energy class). The correlation analysis made it possible to specify that the parameter Q has a direct correlation with pressure, while its dependence on temperature and humidity is manifested only at the level of trends. Based on the revealed regularities a forecasting methodology for dissolved gas concentrations in groundwaters has been developed. Conclusions. The expected reason for the difference in the series of the Q parameter measurements obtained for different water manifestations are the conditions for the recharge and formation of groundwaters. Based on Fourier analysis three main types of harmonics have been identified. They are differently represented in the curves of various types, which is indicative of the complex correlation of factors. According to the results of statistical analysis, the studied parameters form three clusters. The factors affecting gas emanations can be classified into external and internal, whereas the effect of the former on radon concentration has appeared to be stronger in the monitoring period than the influence of the latter. The correlation analysis data have shown that the volume activity of radon is regularly dependent on pressure, slightly less dependent on temperature and humidity. The quantitative analysis of the application results of the proposed forecasting method of dissolved radon concentrations has shown the averaged 80% convergence of calculations.

77-85

Authors: A.A. Peshkova, A.V. Miromanov

The purpose of this work is to develop a conceptual model of a geo-informational project that will improve the integrity and self-descriptiveness of the initial geological and geophysical data when searching for oil and gas deposits, allow to avoid information duplication as well as promptly provide the user with relevant geological and geophysical information in the process of geodata base development. Method. The method of conceptual (infological) design is used to form a general representation picture of geological and geophysical data. Results. Geological and geophysical data used at the enterprise are considered. Description is given to the software environments where geological and geophysical information is processed. The main users of the geoinformational project are appointed. The main performance capabilities of the geoinformational project are identified and the conceptual model of the project is created and described. Conclusion. The created concept of system operation gives an opportunity to form an infologic model of the developed geoinformational project. The latter will allow to collect and analyze the received information, store initial geological and geophysical information and provide the access to geological and geophysical materials. The application field of geoinformation technologies is important and demanded as the use of geoinformation systems for the search for oil deposits and forecasting of oil and gas accumulation zones has shown that modern geoinformation systems fix researchers up with purpose-built tools opening new opportunities for creating forecast maps and making the entire search and forecast process more justified, and the result – more reasoned.

94-97

Authors: S.A. Sverkunov, A.G. Vakhromeev, N.N. Martynov

The Purpose of the paper is study and analysis of mining-and-geological conditions of drilling of deep wells for oil and gas in the South of the Siberian platform, the search for the solution of the existing problems associated with the elimination of drilling mud absorption and such complications as differential sticking of the drill string and casing string. Methods. Production data obtained at well-drilling in the Republic of Sakha (Yakutia) and the Irkutsk region have been collected. Their statistical researches have been conducted. Results. Having analyzed the data collected from production facilities the most effective method against differential sticking has been chosen. Conclusions. A number of fields of Eastern Siberia (including the Irkutsk region, the Republic of Sakha (Yakutia) are located in the geological conditions predisposed to the differential sticking occurrence. Differential sticking of drill and casing strings regularly arise in such geological conditions that break normal working process of well drilling and require additional costs. Moreover, the elimination of this type of sticking is extremely expensive and complicated, and even impossible sometimes. All these cause considerable economic losses in the cycle of well-drilling for oil and gas. The forecast and prevention of differential sticking will significantly facilitate the problem of development and prospecting drilling. The measures proposed by the authors will allow an unconstrained drill-string running in the conditions of abnormal low pressures in the open bore hole. They will also allow to liquidate an immediate differential sticking with minimum economic and temporary losses