A Study On The Reservoir Characteristics And Dominated Factors Of The UPPer Paleozoic At Well Su48 Area In The West Area Of Sulige Gas Field

With the techniques of core observation, physical property analysis, casting section, scanning electron microscopic, grain size analysis, pore image, XRD, high pressure mercury intrusion, constant speed mercury intrusion, relative permeability and nuclear magnetic resonance, the thesis makes a thorough research on the reservoir of the Upper Paleozoic at well su48 in the west area of Sulige Gas Field, focusing on reservior's pore structure character and filtration characteristics. The physical property of reservoir is multiple influenced by deposition, diagenesis and tectonism. The conclusions go as follows:(1)The sedimentary system of upper P2X8 and P1s1 belong to braid river delta plain, lower P2xg belongs to meandering river delta plain, including natural levee, distributary channel, channel bar and point bar microfacies. Quartz sandstone and lithic quartz sandstone are the main type of sandstone. The interstitial material are mainly Kinetics,hydromica, Silicon and Carbonate Cement. The physical property of upper P2x8 is better than P1s1 and lower P2x8 as a whole(2)The pore types of the P2x8 reservoir are mainly intergranular pores, dissolved pores and intercrystal pores. The pore types of the P1s1 are mainly dissolved pores and intercrystal pores.Their pore radius are similar. The main throat types are slice-shape throat, dotted throat and tube-shaped throat. Their throat radius are relatively different. The throat radius of lower P2x8 is higher than upper P2x8 and P1S1.So the pore structure of lower P2x8 is more developed than the other two layer.(3) The main influencing factors of the movable fluid and irreducible water saturation is not only include the porosity and permeability, micro-fracture, but also filling degree of clay mineral in pores, secondary porosity and recrystallization.(4)The main controlling factors for reservoir's physical property are sedimentary microfacies, diagenesis and tectonism. The microfacies of natural levee is at the edge of river, which are characterized by weak water power, poor sorting, small or fine rock grains and tight lithology, causing poor physical property. On the contrary, distributary channel is at the center of the river, where water power is strong, separation is coarse, quartz content is high, causing better physical properties. Diagenesis has a dual influenc of porosity. During the course of diagenesis, the compacting action, pressolution and consolidated filling destroyed the physical property of reservoir, which makes the primary pore of this area reduced greatly. Compaction and cementation made the reservoir respectively lose 29.46% and 10.7% porosity. This made bad effect on physical properties. But dissolution made the reservoir increase 3.2% face porosity. And micro-fracture also made permeability increased a lot.Besides, the reservoir's structural nose play certain control action on Oil and gas accumulation and gas water distribution,but could not play a decisive role.