Research On Reservoir Characteristics Of Fuxian Formation And Yan-10Oil Reservoir Set In Wuqi Area In Ordos Basin

Wuqi area is located in the western of Ordos Basin. Fuxian Formation and Yan-10oilreservoir set of the early Jurassic and early Jurassic strata is principally producing formations inthe study area. The thickness of single sand body varies greatly with bad physical property andobvious anisotropies, and complex relationship between oil and water is the typical characteristicsof this layer. This article through the drilling section, core observation combined sexual material,logging data analysis and the analysis test material, in ordos basin area of Fuxian formation andYan-10oil reservoir set of WuQi area, sedimentary and sand body exhibition cloth division andcorrelation of the characteristics of the system, on the basis of reservoir characteristics of thesystem, and discuss the control factors of reservoir and favorable areas.Based on the above researching, this paper has been gained research results and newknowledge:1. In stratigraphic classification and sand body statistics, on the basis of WuQi area as earlyJurassic and early Jurassic paleogeomorphology restored and characterization. Confirming Fuxianformation and Yan-10oil reservoir set of the research area is mainly developed by the braidedfluvial river sedimentary system.2. The main river channel of Fuxian formation is gravel braided river course. The easternslope is th sedimentary microfacies of the depressions of river edge facies. In this area, sand bodydistribution is discontinuity in transverse and with thin thickness. The main river channel ofYan-10oil reservoir set is sand braided river course. River inherited the characteristics of the riverchannel of Fuxian formation, subprime river channel is more developed on the slope of the river.3. Combined with the cores, chip analysis and other test material, this paper points out thatthe lithic arkose is the main sandstone type in the reservoir stratum of study area. There are mainlyfive kinds of Diagenesis in the reservoir stratum, such as Compaction, cementation, dissolution,metasomatism and productions of the authigenic mineral. The reservoir performance is controledby the sedimentary facies, types of rock, diagenesis, and so on. The research results show thatearly chlorite cementation, dissolition and production of authigenic kaolinite by metasomatitefrom feldspar has a constructive role for the reservoir stratum.4. The oil reservoir distribution in study area of Fuxian formation and Yan-10oil reservoirset is controlled by the ancient geomorphological background. The level2ancient river is notconducive to oil and gas accumulation and preservation. The hill in the revers is the relativelyfavorable position for the oil and gas accumulation and preservation. Venturi nozzle landform isfavorable area for lithologic reservoir. Slope is the most favorable areas of Jurassic. And smallstructure is the point of Jurassic hydrocarbon accumulation. 5. According to the pattern analysis of accumulation conditions and accumulation, andcombined with the sedimentary facies, sand body thickness, reservoir physical properties,reservoir heterogeneitya and water-oil relations research achievements, predicting the favorablearea for Fuxian formation and Yan-10oil reservoir set. The ancient river valley slopes on bothsides of the high point of slope river "watershed", the secondary river source and two venturinozzle terrace is the key blocks. Favorable areas locate in northeast and southwest of the studyarea.