The Reservoir Evaluation Of Chang6Member In Zhangcha Xingzichuan Oil Field, Ordos Basin

Research area in Zhangcha of Xingzichuan oil field, which exploration area amount to120k2m and is located in the middle of Ordos basin and Northern Shanxi monocline. Chang6member is the major oil producing zone. In order to improve productivity and regulatedevelopment performance, it needs to have a comprehensive and deep awareness to thereservoir geologic characteirstic in the research area. The thesis is theoretically based onpetroleum geology, sedimentary petrology, erservoir geology, reservoir description andtechnology of reservoir estimation. Under basic geologic condition and applied with rock corcobservation cast slice, electron microscope scanning，mercury penetration analysis and otherkinds of theories and methodologies about reservoir research, it researches the sedimentarymicrofacies, law of spread of sand body, reservoir petrologic charactcr, microscopic reservoirpore structure characteristics, diagenesis, reservoir physical property character, reservoirheterogeneity. And it forms logging reservoir parameter interpretation model. On the basis ofreservoir characteristics and controlling factors of Chang6member, we classify and evaluatethe reservoir in the area.Under constraint of the key horizon of research area, Yanchang group was ifne classedi114nto Chang6^1-1,Chang6^1-2,Chang6^2-1,Chang6^2-2,Chang6³and Chang6⁴correlated by theantitheses of thickness cycle. Chang6^1-2，Chang6^2-1Chang6^2-23and Chang6³are major oilproducing layer. The research Chang6member is on Ansai delta. Distributary channel andinterdistributary are the major sediment microfacies. The river channel direction isnortheast-southwest. The channel develops steady and sand body is distributed banding.The major type about sandstone classiifcation of Chang6member is feldspar-lithicifne-sandstone. The degree of sorting is well. The clastic granule mostly is subangularity andlinear junction. The sandstone reservoir interstitial material of Chang6member mostly isauthigene and cementing material content is the major part. The research area major pore typeis corrosion intergranular pore, next is juvenile origin intergranular pore and intragranulardissolved pore. The average pore diameter and throat size of Chang6reservoir is7Qim and0.74|im. It belongs to axial canal-thin throat and microbore-micro thin throat. The researcharea diagenesis mostly is compaction, pressolution, cementation, denudation, cataclasis and so on. The compaction, prcssolution, cementation, denudation is the most significant effect onreservoir physical property.Based on the condition of research area reservoir development and actual productivitysituation, combined with reservoir physical property, microscopic pore structure character,reservoir heterogeneity and so on, the reseacrh area of Chang6member is classiifed intoI, IIJII and IV.They stand for good, preferable, bad and ifnely reservoir. The I reservoirdistributes8areas; The II and III preferable reservoirs dominate in the area，distribute large;The IV finely reservoir universally distribute in the area.