Study On Rock-Solution Development Laws Of Carbonate Rock Beneath Salt And Its Reservoir Evaluation In The Tahe Oil Field

Through studying palaeo-rock-solution development characteristics and reservoir prediction technique in the salt areal coverage of Tahe oil field, combining drilling, well logging, testing and the production of reservoir seismic prediction, the thesis synthetically appraised carbonate rock beneath salt and chose the developmental zone of favorable reservoir in priority. Aiming at heterogeneity of rock solution-fracture reservoir of ordovician carbonate, the thesis studies palaeo-rock-solution development laws and reservoir distributing laws of ordovician carbonate. To adopt available methods carries through reservoir evaluation and prediction, we draw the following conclusions:1. The studies shows that rock-solution of the middle Caledonian act on dominant action in the south of the salt areal coverage of Carboniferous.2. The degree of palaeo-rock-solution development is vertically different, and it is controlled by layers. Rock-solution of the middle Caledonian is divided into two sections: the upper section and the lower section. The upper section lies in the middle member of Lianglitage formation, the bottom carbonate rock of Qiaerbake formation, Yijianfang formation and Yingshan formation. Layers of solution-fracture is the best in the upper Yijianfang formation which there is 60m to T₇⁴ interface.3. Tectonic action is the primary factor that controls palaeo-rock-solution development of ordovician carbonate beneath salt. Under NWW-SEE major stress controlling, Tectonic distortion of approximately NWW-SEE Akekule swell is intense. Fault and fracture provide infiltration channels for Rock-solution of the middle Caledonian, and form secondary solution pores and big caves.4. Solution-fracture reservoir is the best favourable reservoir type.5.Reservoir of carbonate rock beneath Salt distributes Lianglitage formation, Yijianfang formation and Yingshan formation.6.The synthetical studies show the reservoir of the area beneath Salt of middle-lower Ordovician is bad than the north area of the early Hercynian rock-solution development.