松辽盆地北部下白垩统泉头组三、四段碳酸盐胶结物分布及其主控因素*

在高分辨率层序地层学研究的基础上，结合镜下薄片观察、电子探针分析、包裹体测试和物性分析数据，对松辽盆地北部地区下白垩统泉头组三、四段碎屑岩储集层碳酸盐胶结物的分布及其主控因素进行分析。结果表明：泉头组三、泉四段地层平缓、埋深跨度小、成岩作用变化弱，碳酸盐胶结物主要受沉积微相和基准面旋回控制；由物源向盆地方向依次发育的曲流河水上分流河道和水下分流河道中，碳酸盐胶结物含量在岩性特征、分选磨圆和泥质含量等因素的影响下呈逐渐增加的趋势；不同中期旋回相同沉积微相的储集层中，碳酸盐胶结物含量不同，并随着长期基准面上升而表现为逐渐减小的趋势；由沉积微相和基准面旋回共同引起的沉积环境差异，而导致碳酸盐胶结物含量的规律性变化，是影响河流相储集层非均质性的重要因素之一。

Distribution of carbonate cements in the Members 3 and 4 of Lower Cretaceous Quantou Formation of northern Songliao Basin and its main controling factors

In order to study the distribution characteristics of carbonate cement and the controling factors in clastic reservoir of the Members 3 and 4 of Lower Cretaceous Quantou Formation in northern Songliao Basin. The theories of high-resolution sequence stratigraphy, and the methods of microscopically slice observation, electron microprobe analysis, fluid inclusion testing and physical properties analysis were used. The results showed that the strata of Members 3 and 4 of Quantou Formation in northern Songliao Basin were gentle, and they were buried at depths of small span, diagenesis of them was weak, and carbonate cement was mainly affected by sedimentary microfacies and cycle of base level. In the direction of provenance area to the basin, values of the content of carbonate cements in different sedimentary facies of meandering river, distributary channel and submerged distributary channel were different. At the same time, influenced by factors such as lithological character, sorting and rounding of grains, shale content, etc, the content of carbonate cement increased gradually. Values of content of carbonate cement were different in different medium cycles of the same sedimentary microfacies types of reservoir, and with the long-term base level rising, they showed a decreasing trend. The regular change of content of carbonate cement due to the difference in sedimentary environments controled by microfacies and base-level cycles is one of the important factors which influence the heterogeneity of fluvial reservoirs.