Basins Santanghu Fluid Inclusion Study

Santanghu Basin is a composite and reconstructive basin, which lied on the fold belt in Permian. The development and evolution of the SanTangHu Basin were controlled by the plate-tectonic background in Hercynian movement, Yanshan movement and Xishan movement. The study of the fluid inclusions aim at the fractured reservoir of middle Permian and the pore reservoir of upper-middle Jurassic. Through microscopic and microthermometry study, acquired fluid inclusion petrographic, microthermometric, salinity and pressure data to facilitate the establishment of a chronology for aqueous and oil-bearing fluid inclusions, the direction of petroleum migration and origin:1. Fluid inclusion petrography of Santanghu Basin was complex: The thermomaturation of Tiaohu sag was higher than Malang sag, The thermomaturation of Luocaogou formation in Permian was the highest than the others formations. The fluid inclusion in Tiaohu sag were liquid hydrocarbon-bearing inclusions and gaseity hydrocarbon inclusions with a high degree of fill, which in Malang sag were liquid hydrocarbon-bearing inclusions. The content of hydrocarbon inclusion in Tiaohu sag was higher than Malang sag, which in Tiaohu formation was higher than Xishanyao formation. The primary hydrocarbon inclusion in Jurassic were liquid hydrocarbon inclusions and two-phase liquid+gaseity hydrocarbon inclusions, which in Permian were liquid hydrocarbon-bearing inclusions and gaseity hydrocarbon inclusions. The contentof fluid inclusion in Jurassic was higher than Permian.2. The fluid inclusion homogenize to the liquid phase between 60 and 240 ℃, show two peak value and the main part in the range 110-150℃ and 190-210℃. The peak value of homogenization temperature in Tiaohu sag in the range 110-145℃,which in Malang sag is in the range 120-150℃. The peak value of homogenization temperature in Tiaohu formation in the range 120-160℃, which in Xishanyao formation in the range 110-150℃, both of them have a higher homogenization temperature in the range 190-210 ℃.3.Secondary inclusions in detrital quartz show obvious relativity with the non-inherit microcrack, which differentiated between reticulate microcrack and unitary microcrack. The fluid inclusion style in unitary microcrack were aqueous inclusions and liquid hydrocarbon-bearing inclusions, the homogenization temperature in the range 100-125 ℃, liquid hydrocarbon inclusions displayed weak-brown to yellow flurescence. The fluid inclusion in this epoch were trapping in the Cretaceous and maybe have some relativity with early Petroleum migration. The fluid inclusion style in reticulate microcrack were aqueous inclusions, two-phase hydrocarbon inclusions and gaseity hydrocarbon inclusions, the homogenization temperature in the range 130-160℃, liquid hydrocarbon inclusions displayed weak yellow flurescence. The fluid inclusion in this epoch were trapping in the late Jurassic and maybe have some relativity with the Permian heat flow. The reticulate microcrack in Tiaohu sag were ascendent, which thermomaturation was the higher than Mlang sag. The reticulate microcrack of Tiaohu formation in Permian were ascendent, which thermomaturation was the highest than the others formations.4. The fluid inclusions in Tiaohu sag were trapping in middle-late Jurassic, The fluid inclusions in Malang sag were trapping in late Cretacence.5. Base on the inclusion petrographic and microthermometric study, find some new cognitions: (1)The precondition of microthermometric are fluid inclusion petrography study and diagenesis study, which also is the base of multiperiodity.(2)Use the homogenization temperature to calculate the geothermal gradient should base on the fluid inclusion trapping in the same diagenetic stage at different depth.(3)The time that fluid inclusion trapping in the microcrack was't corresponding the tectogenesis time.(4)Aromatic hydrocarbon displayed flurescence, so fluid inclusion can't display flurescence which maybe have hydrocarbon.(5)The fluid inclusion with high homogenization temperature in Jurassic meaning the deep heat flow have influenced them, which need more proofs to prove.