关键词: 东营凹陷, 古近系, 碳酸盐胶结物, 分布特征, 主控因素

Abstract: Carbonate cementation is the main type of cementation of sandstone reservoir of Dongying depression. Studies suggest that content of carbonate cementation gradually increases with the burial depth in Dongying depression. The relatively thick sand layer with carbonate cements is mainly distributed in Es³, followed by Es¹ and Es². Calcareous sandstones in Es⁴ are only seen in the small depression surrounding areas. Within Dongying depression, carbonate contents at the north steep slope belt, central rise belt, and south gentle slope belt are significantly different with the north belt contain more carbonate cements than the south belt. Under the same burial depth, the carbonate contents in the south and north are higher than that in central rise belt in Dongying depression. In faulting areas, carbonate contents are variable and dispersedly distributed, whereas in small depression areas, carbonate contents are of minor change and distributed in a roughly similar depth. The favorable facies belts for the deve-lopment of sandstone layers with carbonate cements include near-bank subaqueous fan, underwater alluvial fans and deep-water turbidite fans, and generally high carbonate contents in coarse grained sandstones. Under the same burial depth, the smaller thickness of the sandstone layer is, the stronger carbonate cementation is. When the sandstones are surrounded by carbonates or thick mudstones, then high carbonate contents will be found in the sandstones.

Key words: Dongying depression, Paleogene, carbonate cements, distribution characteristic, main controlling factors