The Sedimentary Microfacies Research Of Qingshankou Formation In Yaoyingtai-Dahl Khan Region

The research object of this paper is the Qingshankou group of Yaoyingtai-Dahl Khanarea. Basing on comprehensive use of the principle and methods of sedimentology highresolution sequence stratigraphy and Reservoir geology and the technology of Reservoirprediction,we has studied the Sedimentary facies,diagenesis and reservoir characteristics ofthe target zone in this area systematically; described the Sedimentary micro facies, thedistribution of sand body, diagenesis and reservoir characteristics of Various sandstonegroups in this area meticulously; analysed the Source direction of the deposition and the lawof temporal and spatial evolution of macro depositional system in this area; discussed thefactors affecting the reservoir properties; seen into types of sedimentary facies and sand bodydistribution law and conducted a comprehensive evaluation to the sandstone reservoirs of thearea eventually.Through detailed study,we have obtained the conclusions as follows:We applied High frequency sequence stratigraphy theory to reservoir sand group levelstratigraphic correlation and determined the sequence as the base comparison unit on the basisof " hierarchical control, sequential contrast " principle[1]. We divided the first section of theQingshankou Formation into5parasequences (sand groups),and the second into10parasequences (sand groups)and the third into3parasequences (sand groups). And we alsocontrast18parasequences (sand group) of more than80drillings with each other inYaoyingtai area.Through a large number of fine core observation and the study of the analysis of singlewell faces and the wells facies, and the lithology, sedimentary structure, fossils, sedimentarysequence, rock assemblage and logging curve characteristics, we have recognized that varioussubfacies and microfacies types of Qingshankou Formation delta facies developed completely,including distributary channels, onshore distributary, underwater distributary channel, estuarydam microfacies which are best developed in this area. The front subfacies of the first twosections of Qingshankou Formation present that estuary dam is great development but sandsheet is extremely not development characteristics.Take parasequence (sand group) as a unit, we have compiled the planar graphs ofsandstone thickness and sand rate dispersion system in Yaoyingtai area. According to digital data of the well logging curves, we took CarbonSoft for lithologic section restoration,established sedimentary microfacies models and logging facies models, through coring wells,collected elements parameters of well logging curve shapes, and used DF-GVision forautomatic sedimentary facies identification. We use this procedure for the phase analysis andplane facies study of single well facies and joint wells in this area.