RESULTS OF HYDROKARBON POTENTIAL ESTIMATION OF IMPACT STRUCTURES AREAS LOCATION BY FREQUENCY-RESONANCE METHODS OF REMOTE SENSING DATA PROCESSING

Purpose. The purpose of the paper is to evaluate hydrocarbon potential of the areas of large Siljan impact crater location in Sweden, the local exploration block within it, and two small structures in the United States; to select the optimal sites within the surveyed areas for exploration wells laying, to study the possibility of using direct-prospecting remote methods to detect meteorite fragments location; to develop and improve the techniques of geophysical direct-prospecting methods and technologies application during oil and gas prospecting and exploration in the reservoirs of conventional and unconventional types. Design/methodology/approach. Experimental studies were conducted using the mobile direct-prospecting technology of remote sensing (RS) data frequency-resonance processing and interpretation, which operates within the “matter” Paradigm of Geophysical Research. The method of an operative assessment of the fluid pressure maximum values in the reservoirs is an important component of this technology. In the course of the investigations, this method was improved by adding the ability of the reservoir pressure assessment in various intervals of cross-section, included depths). Findings. In the area of the Siljan crater location we discovered and mapped 16 anomalous zones of the “gas”, “oil + gas”, “gas + water” type and 6 anomalies of the “gas” and “gas + water” type within the local area. Values of fluid pressure in reservoirs vary within anomalies, ranging from 2,2 to 8,0 MPa. According to the scanning data, one gas-saturated horizon and four horizons with water and gas were located at the top of the cross-section. Using the technique of the reservoir pressure assessing at different intervals of the section within the “Gas” anomalous zone, the following additional intervals for searching were identified: 1) 420?500 m, H = 80 m; 2) 1120?1150 m, H = 30 m; 3) 2880?3140 m, H = 260 m; 4) 5185?5195 m, H = 100 m. The drilled wells in the Siljan crater (Gravberg-1 and Stenberg-1 deep wells included) does not fall within the contours of the detected anomalies. In the area of the Panther Mountain crater location (USA), six anomalous zones of the “reservoir of gas” type were found. In the anomalous zone “Gas-1”, three intervals of possible accumulation of gas were identified ? two intervals in the anomalous zone “Gas-2” and one interval in other four anomalies. In the “Big Basin” search area (USA), five anomalous zones of the “oil + gas” type and four anomalous zones of the “gas” type were mapped. Within the anomalies contours, two intervals promising for oil and gas accumulations detection were found. The observed anomalies should be considered as priority local areas for detailed study by geophysical methods and drilling. In effect, these are “Sweet spots” zones. Practical value/implications. The results of the studies indicate the presence, within impact structures, of local areas and zones promising for the commercial hydrocarbon accumulation. The use of mobile and operative methods of “direct” prospecting for hydrocarbon accumulations in the areas of various type of reservoir (collectors) and structure spreading could significantly improve the success rate of drilling (i.e. an increase in the number of wells with commercial hydrocarbon inflows). The improved method of fluid pressure in reservoir estimation at different levels of the cross-section can be widely used for the operative assessment of hydrocarbon potential of the cross-section deep horizons. The presence of a significant number of anomalous zones of the “oil and gas deposit” type (in crystalline rocks at depth included) within the Siljan crater located on the Baltic Shield can be regarded as additional evidence in favor of the abiogenic origin of hydrocarbons.