Abstract: Research on sedimentary palaeotopography at southwest Luojiazhai area is operated with logging Gama data. It is indicated, on the basis of the comparison with logging curve of almost 100 wells, that the electric property change at lower Feixianguan formation is concentrated at the 50m range from the bottom. Research on sedimentary palaeotopography of early Feixianguan period is conducted with Gama average data of 50m section from bottom of the formation, it is indicated that Gama data range（20～30API）would be favorable for oolitic development, and meanwhile it is also the favorable areas of late oolitic dolomite and oolitic reservoir development, according to favorable facies, high palaeotopography, dolomization at adjacent wells and good quality of reservoir development, the two favorable exploration blocks, QL25PX1 area and DT 7DT 5 are figured out.
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Key words: oolitic reservoir, palaeotopography, Feixianguan, southwest Luojiazhai area