Apostolov O. Improved method of lineament analysis for assessing the prospects of the territory for hydrocarbon deposits explorations

The thesis is devoted to the improvement of the method of lineament analysis for the estimation and forecasting of the territory for hydrocarbon deposits. An important factor of hydrocarbon deposits location and localization is the breaking structures of the lithosphere. One of the rapid and economical methods of studying breaking structures in areas of oil and gas deposits is lineament analysis, which is based on remote sensing (RS) data. Often the results of RS data interpretation are presented in graphical form, that provides limitation for its use in combination with data from geophysical, geochemical and other quantitative research methods, provided in numerical form. Lineament analysis allows to present the results of structural interpretation of remote sensing data in quantitative form (density maps of lineaments), to establish the relationship between hydrocarbon deposits and lineament density values and to forecast the prospects of area for hydrocarbon deposits. The forecast of the territory's prospects for hydrocarbon deposits has been made. A set of search (informative) features has been formed using the probability of the relationship between used features and target objects using the spatial-probabilistic forecasting program. The informativeness of the features has been estimated by comparing the features values distributions within the known objects with the distribution of their values, taken on a uniform grid within the most studied areas. In case of significant differences between these distributions, which have been estimated using the non-parametric Pearson test, the feature refers to the search features. Otherwise, the features have been excluded for further use. For the search features based on the likelihood ratio function, the intervals of the features values with which the forecast objects are connected have been determined and the probability of the relationship between the forecast objects and each features values has been estimated. Deviation of the likelihood function values from 1 indicates prospect and non-prospect areas. All informative search features have been integrated with each other using two-dimensional likelihood ratio functions. It allowed obtaining a predictive assessment of the prospects of the territory using the set of features. The forecast maps have been made on the basis of the received values of the prospects of the territory using the set of features. As a final stage, the generated forecast maps have been analyzed, its reliability has been assessed using all available information about geology and deposits of the study area. The most reliable assessment of the results accuracy can be obtained only through drilling in the proposed areas. However, in practice, this happens very rarely. In cases where there are many known hydrocarbon deposits within the study area, some of them are not taken into account for making forecasts. These objects are then used as control points to assess the reliability of the forecast results. For this purpose, it is necessary to use also the known deposits of hydrocarbons which are located in areas outside the study area but in close proximity to their boundaries. In such case, it is necessary to extend the boundaries of a research area. Final decision about prospects of the area and recommendations for followed research using a set of geophysical methods and drilling are prepared based on the analysis of the forecast map, taking into account all the features that have not been used in the forecasting process for various reasons. To increase the reliability of the results, the map of the prospects of the area should be compiled using remote sensing data in combination with the data of geological and geophysical research. For ease of use in the future, all information obtained in the process of lineament analysis and forecast assessment of the prospects of the territory is stored in a GIS project format. This improved technique is recommended to apply at the enterprises and organizations which carry out forecasting and hydrocarbon deposits exploration on land.