Formation And 3D Geological Modeling Of Y22 Well Area In LFP Oilfield

With the continuous exploration and development of oil and gas fields in China,it is increasingly difficult to find large conventional structural oil and gas fields,which requires researchers to better understand the distribution law and distribution characteristics of residual oil through reservoir comprehensive evaluation and geological three-dimensional modeling technology.The geotectonic position of well Y22 in LFP oilfield is located in the western margin of northern Shaanxi slope belt of Ordos basin.there are many sedimentary systems in Ordos basin,which contain abundant oil and gas resources.This study is based on the Yanchang Formation as the main stratum,systematically analyzed the regional geology and structural characteristics,and made full use of existing well logging,geology,and production data of the oil field.Based on the stratigraphic division and comparison,the sedimentary microfacies and reservoirs were developed.Layered features,sand body distribution,and other aspects of work,finally,the petrel 2010 geological modeling system is used to establish a high-precision 3D geological model of Chang 6,Chang 8 and Chang 9 reservoir groups in Y22 well of LFP oilfield by random modeling method,including 3D geological structure model,sedimentary microfacies model and facies controlled reservoir attribute parameter model.The study shows:(1)the structure of well Y22 in LFP oilfield is relatively simple and the formation is gentle.the main oil-bearing formation is Chang 6,Chang 8 and Chang 9,and the formation is subdivided into 8 small formation groups:Chang 61,Chang 62,Chang 63,Chang 64,Chang 81,Chang 82,Chang 91 and Chang 92.(2)the Chang 6 reservoir has an average porosity of 9.8%and an average permeability of 1.4×10-3m2;The Chang 8 reservoir has an average porosity of 6.0%and an average permeability of 1.2×10-3m2;The Chang 9 reservoirhas an average porosity of 5.7%and an average permeability of 0.6×10-3m2.The sandstone of Chang 6 reservoir group belongs to ultra-low porosity reservoir.The sandstone of Chang 8 and Chang 9 reservoir groups belongs to low-ultra-low porosity and ultra-low permeability reservoirs with poor physical properties.(3)the reservoir drive type is elastic-dissolved gas drive reservoir.The study area is reformed by water flow to form delta deposit,which is developed into delta front sedimentary subfacies and subaqueous distributary channel,interdistributary bay and estuarine bar sedimentary microfacies.The sand body distribution shows a low～high～low trend of nearly north west～south east extension.(4)finally,through the three-dimensional geological model,it can be seen that the porosity,permeability and saturation of Yanchang formation in Y22 well area of LFP oilfield are highly heterogeneous,the distribution of porosity and permeability has a good corresponding relationship,and the model is in good agreement with the actual situation.