Reservoir Characteristics And Main Controlling Factors Of The Chang 6 Tight Sandstone In Huangling Area,Ordos Basin

Huangling area is located in the south of Ordos Basin.The Chang 6 oil reservoir set of Yangchang Formation is principally producing formations in the study area.The thickness of single sand body varies greatly with bad physical property and obvious anisotropies,and complex relationship between oil and water is the typical characteristics of this layer.In this paper,the Chang 6 reservoir in the Huangling area of the Ordos Basin is studied by using the sedimentary petrology,reservoir sedimentology and logging geology.Based on the system division and comparison of sequence stratigraphy,sedimentary facies and sand body distribution features,to systematic research reservoir charater characteristics and reservoir control factors.This paper has been predicted the favorable areas.Based on the above researching,this paper has been gained research results andknowledge:1.Based on the analyse of outcrop profile,drilling profile,core observation and logging data,confirming this areamainly developed as the background of semi-deep lake facies ingravity flow sedimentary environment.Sandy debris flow,turbidity flow and Semi-deep lake mud as the main development of the sedimentary microfacies.2.From the sand body distribution features of Chang6 oil reservoir set in the study area,distribution of sedimentary microfacies affects the distribution of sand body.The direction of sand body mainly present bands,which is from northeast to southwest,and become repeatedly.3.Combined with the cores,chip analysis and other test material,this paper points out that the feldspar lithic sandstone and lithic feldspar sandstone as the main sandstone types in the study area.The interstitial material mainly include clay mineral and carbonate cement.The reservoir diagenesis mainly includes compaction,cementation and dissolution.Reservoirs mostly low porosity and density-nearly density from core property analysis results.By the research on thepore texture of rock,the relationship between porosity and permeability of Chang6 oil reservoir set in Ordos Basin in the study area,it is considered that much higher heterogeneity exists at the innerbed and the plane.4.By analyzing the cores and the reservoir physical properties,it comes to conclusion that sedimentary facie and diagenesis are the main factors controlling the researvior distribution.The sedimentary facies controls the physical property of the reservoir macroscopically.The source direction of the northeast and southwest of the study area determines the direction of sand body extension.Along the direction of the source,the continuity and connectivity of the sand bodies are very good,and the oil content is considerable.It comes to the conclusion that the most destructive diagenesis includes compaction and cementation,and the favorable diagenesis includes dissolution and chlorite cementation which makes the reservoir has better physical propertie.5.Combined with the sedimentary facies,sand body thickness,reservoir physical properties and reservoirheterogeneityaresearchachievements,predicting the favorable area for each section of Chang6 oil reservoir set.And the dominant reservoirs are mainly developed in reservoirs?.