孔店油田馆陶组辫状河—曲流河转换及其控制因素

Controlling factors and transformation from braided river to meandering river, Guantao Formation, Kongdian Oilfield

为探讨孔店油田馆陶组河流类型的转换模式,在沉积学的理论指导下,通过对研究区岩心及测井资料的详细描述,在河流成因岩相类型识别的基础上,确定了6种沉积微相类型,并且通过对馆陶组地层垂向沉积微相、河道堆叠样式和河道宽厚比等的变化特征分析,确定了研究区发育辫状河和曲流河2种类型的河流,并建立了研究区的沉积模式;在此基础上,对河型转换的控制因素进行了分析。研究表明:基准面变化、物源供给及古气候3个因素控制着孔店油田馆陶组河流类型的转换过程。受到基准面的逐渐升高、物源供给能力的减弱及古气候环境变的干热等因素的影响,馆陶组沉积逐渐由辫状河体系向曲流河转换,最终建立了研究区河型演化模式。

In order to discuss the model of fluvial style transform of Guantao Formation in Kongdian Oilfield, based on the detailed description of core and logging data, under the guidance of the sedimentology theory, six sedimentary microfacies were identified by the identification of lithofacies. Through the analysis of the characteristics of variation on vertical sedimentary microfacies, stacking pattern and width-thickness ratio of channels of Guantao Formation, braided channel and meandering channel were identified and the sedimentary model was established in study area. The analysis of controlling factors on fluvial style transform shows that base- level changes, sediment supply and paleoclimate affected the fluvial styles of Guantao Formation in Kongdian Oilfield. With the rise of the base level, the weakened supply and the drying of paleoclimate, the fluvial style changed from braided river to meandering river and regional sedimentary evolution model was established.