Potential of North Caspian shelf according to results of oil and gas occurrence analysis in continental part of Western Kazakhstan
The author discusses geological model of the Kurmangazy area (North Caspian shelf) and reasons for the negative results of exploratory drilling under the collaborative Russian-Kazakhstan project. According to the results of the analysis, these reasons are related to incorrect geological model of the Kurmangazy area, which was approved for exploratory drilling on the basis of 2D CDP seismic data. Another reason is the lack of geologically based views on petroleum potential of the area, which has a complicated structure and not uniquely defined belonging to Caspian or Buzachinsky type of the section and, accordingly,
to stratigraphic position of pay intervals. The author considers the objective laws of spatial and stratigraphic distribution of explored oil and gas reserves and petroleum potential of the South Mangyshlaksky and North Buzachinsky petroleum areas of the North Caucasus – Mangyshlaksky Petroleum Province, and analyses the association of the revealed patterns with zonality
of neotectonic evolution of the region. Based on the analysis of correlations of the most recent tectonics with oil and gas potential of the Turansky Plate western part, and on the revealed objective laws, the assessment of petroleum potential of the Kazakhstan shelf of the Caspian Sea is conducted. In order to relive the Kurmangazy project, 3D CDP seismic survey is necessary in the area with the following high-quality geological interpretation on the basis of the author’s ideas of key role of the most recent pull-apart tectonics in formation of structures and oil and gas accumulations. To select an exploratory well location with high probability of a deposit discovery, it is necessary to identify the structural and deformation inhomogeneities of the blockbased structure in the shear zones by means of building 3D geomechanical model of the area, and to substantiate the structural features of rock tension and permeability in the volume of seismic cube. In order to determine the pay (target) search interval, the assessment of the petroleum potential and geopetroleum zoning on a genetic basis is required that is taking into account the ideas of the deep hydrocarbon genesis and the young age of their modern accumulations.
Key words: Kurmangazy area; horizontal shear structures; structural and deformational inhomogeneities; most recent pullapart tectonics; petroleum potential.
For citation: Timurziev A.I. Potential of North Caspian shelf according to results of oil and gas occurrence analysis in continental part of Western Kazakhstan. Geologiya nefti i gaza. 2020;(3):29–41. DOI: 10.31087/0016-7894-2020-3-29-41. In Russ.
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Doctor of Geological and Mineralogical Sciences,
JSC “CGE”, Moscow, Russia