The Study Of Karst Fracture-Cavity System Of Ordovician In Block 8 & 10, Tahe Oil Field

Lithologic section fram of carbonate buried hill is complexity, and develops more atmospheric water karstification, the study of karst reservoir being not thorough, development characteristic of karst fracture-cavity reservoir being not perspicuity, Ordovician, in Block 8 & 10, Tahe Oil Field. So it is important signification to oil & gas exploitation and prospect for allocation that how effectively develop study about carbonate fracture-cavity type reservoir, especially karst carve type reservoir.The paper contraposes fracture-cavity type reservoir of block 8 & 10, in Tahe Oil Field, and develops study of carbonate fracture-cavity type reservoir by use of integrated study ways of combination geology, logging, testing and exploitation dynamic data, and theory with technology about Karst geology, longing geology, reservoir geology, petroleum reservoir engineering-exploitation, at the same time, and bringing into play interdisciplinary superiority, and adopting ways of wellpoint, cave contrast section, plane, system and static with dynamic combination. By synthetical analysis, it obtains conclusions as follows:1. Based on the Palaeo-geomorphology Restoration of early Hercynian, and by mapping out contradistinction section of cave layer, showing comparing Block 8 & 10 with main body area of Tahe Oil Field, giving priority to atmospheric water karstification of early Hercynian, and developing cave layers of three karst cycles in portrait, in Block 8 & 10, but being differ from main body of Tahe Oil Field. Being characteristic with cave layer of kast cycleâ…¢, and developing three cave layers transition into only one cave layer from northeast to southwestward, in work area.2. Mapping out different cycle karst facies belt maps, showing mostly developing karst slope and basin, and karst slope of cave development located the north of Block 8 and northeast of Block 10 during karst cycleâ… , distributing the mostly area of Block 8 and and northeast of Block 10 during karst cycleâ…¡, covering with the whole work area during karst cycleâ…¢.3. Making use of static data, based on the Palaeo-geomorphology Restoration of early Hercynian, according to neighborhood rules, combining with tectonic, pataeodrainage pattern, and dividing cave system by different karst cycle.4. Based on the fracture-cavity system form static data, using dynamic data, In accordance to different karst cycle, developing study of fracture-cavern connectivity between wells from initial formation pressure, reduced pressure, similar well interference test, petroleum deposit productive feature and crude oil physical property.5. According as fracture-cavern connectivity between well, combing with static and dynamic data, In accordance to different karst cycle, developing study of fracture-cave system and fracture-cavity unit6. Karst-cavern type reservoirs being divided into 5 belts, 7 fracture-cavity units and many isolated fracture-cavity units, and combining with production characteristic of fracture-cavity unit to develop evaluate of oil & gas exploitation objects in work area.