Research On Paleozoic Tectonic Evolution In Area Of Marsel In Southern Kazakhstan And Its Relation With Hydrocarbon

The area of Marsel located in southern Kazakhstan in the north of Central Asia,cross South Kazakhstan Province and Kyzylorda Province,where oil and gas resources are abunt.The area of 1.85 x 10~4km~2 located in the west of central Chu-Sarysu Basin is mainly developed in the upper Paleozoic strata and where the recoverable gas reserves reach 197 x 10~8m~3.The area of Marsel is studied with the theory and method of petroliferous basin,based on the interpretation on 2D and 3D seismic data of the area.We emphatically analyze and summarize the characteristics of fault system,typical structural styles and structure characteristics of the target layers.Studies suggest that the tectonic evolution process is divided into four stages,respectively as initial rifting in late Devonian,Carboniferous period of passive continental margin,subduction collision in Permian and depression period in Mesozoic.Based on the comprehensive consideration of the mechanical properties of rock and paleostress,establishing a reasonable geological model and mechanical model,and finally establish area Marsel of tectonic stress field in finite element model.ANSYS finite element numerical analysis was carried out to restore the stress distribution during the crack period.In addition,according to criteria of rock fracture and rock deformation energy values,establish a mathematical model of the crack density then calculate.Eventually predict crack distribution of purpose layer and choose the favorable zone.