Fault Systems And Its Control On Hydrocarbon Accumulation In South Beier Sag

South Beier Sag is an important basin for oil and gas exploration,and its fracture development is closely related to oil and gas,whether can correctly explore the fracture function that controlling of the hydrocarbon accumulation and distributionn is of great significance to understand its oil and gas distribution and to guide oil and gas exploration.In the full use of south Beier Sag geological,seismic,logging and analysis on the basis of test data,the 3 d seismic fine interpretation,typical reservoir anatomy and fracture system and oil and gas distribution between application and distribution relationship analysis method,the fracture system and its evolution characteristics,reservoir type and water distribution and fracture effect on controlling the hydrocarbon accumulation function and model for the comprehensive and systematic study,We can obtain the main results in the following aspects.1,South Beier Sag fracture of the formation and evolution experienced four stages,namely Tongbomiao group～2nd Member of Nantun for stretching deformation period.Damoguai river group to 1St Member of Yimin a sedimentary period for relative stationary phase;The 2nd or 3rd Member of Yimin of sedimentary period for a torsional deformation period.The sensitive group the end to Qingyuangang period of subdivided for pressure torsion reverse deformation period.According to the fracture geometry characteristics,deformation times and deformation mode,can be divided into four sets of fracture system,namely early stretch fracture system(Ⅰ type),medium a torsional fracture system(II type),early middle stretch a torsional fracture system(Ⅰ-Ⅱ type),early stretch a twist in the middle of the late reversal fracture system(Ⅰ-Ⅱ-Ⅲ type).2,South Beier Sag reservoir types mainly have three kinds,namely reverse fault barrier,fault and lithology and lithologic updip pinching reservoir.Oil and gas in the longitudinal due to cover segmentation and the influence of the fracture communication formed two sets of primary and a secondary petroleum system,both have complementary phenomenon,two sets of primary petroleum system are respectively in Nantun group and 1St Member of Tongbomiao group;and secondary petroleum system is in one section.Oil and gas in the plane is banded distribution,distribution in the east time concave north depression trough and south depression tank,and the north depression tank oil area is the biggest.3,North and South depression fracture on reservoir formation control function mainly displays in the two aspects:Fracture provides migration conditions for oil and gas,(1)the early stretch fracture make 1st and 2nd members of Nuntun reservoir side joint,which is beneficial to oil lateral migration;(2)the long-term development fracture for secondary reservoir formation provides favorable conducting channel;Fracture provides shield condition for oil and gas accumulation,(1)fracture and cover effective configuration control the oil distribution horizon;(2)closed faults have provided the traps for oil and gas gathering(3)the reverse fault "back" low elevation control primary reservoir gathered horizon;(4)reverse fault-fan body control secondary reservoir gathering horizon;(5)enrichment of oil and gas layers is under the control of the ability of fault sealing4,South Beier Sag fracture effect on controlling the hydrocarbon accumulation mainly have three kinds of modes:(1)the reverse fault "back" low elevation control primary hydrocarbon accumulation mode;(2)the early stretch fracture butt joint control of the primary hydrocarbon accumulation mode;(3)reverse fault-fan body control secondary hydrocarbon accumulation mode.