The Positive Reversal Structure Characteristics And Petroleum Geological Significance In The Bachu Area

Bachu uplift in the Tarim Basin, central uplift with the western part of experiencing the early Paleozoic extensional rift, late Paleozoic, Mesozoic squeeze reversal positive-reversal structure evolutionary history.In recent years, with the Continuously improve the success rate of the oil and gas exploration in thepositive-reversal structure,it is necessary for the guidance of experienced oil and gas exploration in Bachu uplift which experienced tectonic movement superimposed.In this artical,By a large number of earthquakes fine interpretation, the use of the identification method of the typical positive-reversal structure, combined with the tectonic evolution and positive-reversal structure quantitative research methods, and obtained the following understandings:(1) Use positive-reversal structure comprehensive identification method,such as Seismic facies, fault and structural characteristics, We have identify the Serikbuya fault, Contador Kumu fault, Hemmi Ross fault, Antique Hill fault, Mazhatage fault, Kalashayi fault, Tumxuk fault,8positive-reversal structure in the Bachu Uplift.(2) Use Mitra theory by geometry and mechanism of action classfy Bachu uplift positive-reversal structure,We divided the Bachu uplift positive inversion fracture to inheritance inversion type, truncated to take the straight type and reverse truncated type three categories, Serikbuya fault,Contador Kumu fault,Hemmi Ross fault,antiques Hill on thelst fault are inheritance inversion type, antique Hill on the2nd is truncated to take the straight type, Kalashayi fault and Tumxuk fault are reverse truncated type。(3) There is a new understanding of Bachu positive-reversal structure The reversal of sub-division of this study;Caledonian early Bachu positive inversion fracture have experienced extensional rift.Caledonian the mid-night screen Serikbuya fault, Hemmi Ross fault, Mazhatage fault, Kalashayi fault, Tumxuk fault be reversed, while Bachu internal faults as Contador Kumu fault and Antique Hill fault began to reverse in the late Hercynian, and inheritance extrusion and the final shape in the Himalayan period.(4) Quantitative evaluation of the growth index and inversion strength method for Bachu positive inversion faults,I think the early tensile strong fault late extrusion reverse is also strong, and the boundary fault of the reverse sequence is consistent, reverse thrust in the mid-night curtain of Caledonian, Overall, the eastern part of the reversal period earlier than the west, inversion strength is south stronger than the north。(5) Bachu area positive-reversal structure the development of highly selective use of faults inclination measurement statistics and the growth of index-line quantitative evaluation found that early faults is less than60°Caledonian early extensional context of late have experienced a reversalto early extensional strong faults late positive inversion strong.(6) The items to display vertical and horizontal differences in the statistical Bachu area oil and gas,We believe that:①large positive inversion faults control the of hydrocarbon source rocks and thermal evolution;②faults term activities provided the conditions for hydrocarbon migration;③positive inversion faults inheritance extrusion control trap size and distribution;④Himalayanof intense activity led to the destruction of part of the trap.