Oil and Gas Exploration
Oil and Gas Exploration is a valuable resource for exploration geophysicists, petroleum engineers, geoengineers, petrologists, mining engineers, and economic geologists, who will gain insights into exploring new methods involved in finding natural resources from our Earth. Sudip Misra, Indian Institute of Technology, Kharagpur, India Sumit Goswami, Defence Research and Development Organization, New Delhi, India
Oil and Gas Exploration
EXPERIENCE OF REGIONAL PREDICTION OF HYDROCARBON DEPOSITS PROSPECTING IN THE VICINITY OF URAL OIL AND GAS PROVINCES
Vladimir S. Druzhinin, Vjacheslav Osipov, and Nikolay Nachapkin
Institute of Geophysics Ural Branch of Russian Academy of Sciences (UB RAS), Ekaterinburg, Russia
This chapter is devoted to investigating oil and gas content in the Ural region according to the position of the Earth's crust deep structure. A significant volume of deep seismic soundings was provided in the Ural region by the Bagenov geophysical expedition, by the Institute of Geophysics (Ural Branch of Russian Academy of sciences), and by the Center of Regional Geophysical Research (GEON) during some decades. We have elaborated a new technology of seismic geomapping, based on new model conceptions about the structure of the upper part of lithosphere. We supplement the base of seismic research by the geological data (information about the oil and gas content of the region), the data of super deep boreholes, and area gravimetric data. That allowed us to construct a geological-geophysical fault-block volume model of the lithosphere (up to 80km), to provide the tectonic mapping according to these cuts: the surface of ancient crystalloid crust and the main seismic geological surface M. On the basis of the obtained information compared with the data of hydrocarbon deposits location, new depth criteria of forecasting deposits in new regions and objects have been developed. We can assign some examples of positive forecasting. They are the Kueda region (south of Perm region) and the region of the town Khanti-Mansyisk.
In the last decade, interest in the information of Earth's crust and upper mantle structure has steadily grown. That knowledge has become required for developing deep submerged sediments, which are the main source for refueling the world base of oil and gas of the 21st century, and for prospecting objects in new areas. Success of prospecting new fields of hydrocarbon (HC) deposits inside the territory of oil and gas areas of the Ural region is too low. One of the main reasons for this may be that the peculiarities of the deep structure chosen for detailed exploration are not usually taken into account. That situation is caused by the lack of sufficiently reliable data on the structure of the Earth's crust, as well as absence of criteria for the prediction of prospective areas. A simplified system of observation in deep seismic sounding oriented on the subhorizontal environment is in conflict with the complex block model of Earth's crust, established by using the dense continuous profiling systems and the results of deep drilling. First of all, we need to have information about the tectonic model of the upper lithosphere and also about the connection between the structural and tectonic elements of the sedimentary cover, including tectonics of crystalline crust and of deep fluid dynamic zones. That will determine the types of the Earth's crust as a generation source of hydrocarbons that contributes to their vertical migration into upper layers of the geological environment. The development of depth criteria that determine the formation of large hydrocarbon deposits was introduced in the 1960s. In the beginning it was realized in profile models, and then in area systems for constructing a geological-geophysical volume model of the Ural's upper lithosphere and scheme of tectonic districts of the crystal crust. Conclusions about the prospects (or nonprospects) of areas were confirmed by subsequent detailed prospecting operations. The need for such an approach at the stage of regional and regional-zonal forecast in this chapter is considered an example of research on oil and gas provinces of the Ural region.
1.1.1. Some Information About Oil-Gas-Reserves of Ural's Region and Their Geological Environment