Reservoir Features Of The Chang6₁ Formation In Shaziwan,Jingbian Oilfield,Ordos Basin

Based on sedimentology,sequence stratigraphy,rock ore,petroleum geology,geophysics,this paper investigates the Yanchang formation in Triassic system of Ordos basin.Through the analysis of the cores and well logging date,in-depth study of reservoir characteristics on the basis of the sedimentary system and sedimentary microfacies of the Chang 6₁ reservoir in the Shaziwan area of the Jingbian Oilfield,Ordos Basin.This paper take out main results and realizations as follows:?1?The Chang 6₁ stratum is characterized by a western-sloping monoclinic structure,and the top structures of each small layer have a good inheritance,and the nose-like bulge develops;The sedimentary facies belong to the delta plain subfacies,the developmental diversion channel and the inter-river microfacies.?2?The Chang 6₁ reservoir sandstone belongs to feldspar sandstone and lithic feldspar sandstone.The cement is mostly turbidite,chlorite,iron calcite and siliceous.The pore types of the reservoir are mostly intergranular pores,dissolution pores,micropores and micro-cracks.Among them,intergranular pores and dissolution pores are the main ones,and the pore combination is dissolved pores and intergranular pores.The reservoir belongs to the low porosity ultra low permeability and low porosity ultra low permeability reservoir.?3?The diagenesis types of the Chang 6₁ oil-bearing formation in the Shaziwan area are compacted,cemented,metasomatized and dissolved.Combined with the type of diagenesis,it is judged that the Chang 6₁ oil-bearing formation in the study area is in the stage A of the diagenetic stage,and the local stage may reach the stage B of the diagenetic rock.?4?The heterogeneity of the Chang 6₁ reservoir in the Shaziwan area is characterized by:interlayer interlayer and permeability parameters showing heterogeneity-homogeneous,layer interval and sandstone density parameters show strong inter-layer heterogeneity,plane sand The plan view of the body distribution and the pore permeability distribution shows that the heterogeneity is also strong;?5?The Chang 6₁ reservoir in the Shaziwan area belongs to the ultra-low-ultra-low permeability reservoir and belongs to the IIIa^IV reservoirs.