Reservoir Of Chang 2 Oil-bearing Formation In Qingyangcha Area,Jingbian Oilfield Research On Characteristics And Main Controlling Factors

This study takes the Chang 2 oil layer group of Qingyangcha area in Jingbian Oilfield as the object,based on drilling,logging,analysis and other data,through a large number of laboratory core observation,thin slice identification,electron probe,scanning electron microscope,logging interpretation,High-pressure mercury intrusion and other techniques,and through the on-site geological survey and other methods,the section of the Chang 2oil-bearing formation is analyzed,and the stratigraphic division and comparison of the target layer of the study area,the development and distribution characteristics of the sedimentary facies,and the rock of the reservoir are carried out.The characteristics of the study and the microscopic pore permeability characteristics of the reservoir were studied.Based on the above research results,the reservoirs of the Chang 2 reservoir were studied comprehensively,and the main controlling factors of the reservoir were studied.It is believed that the reservoirs in this area are mainly light gray,gray-green fine-grained,fine-middle and medium-grained feldspar sandstones,belonging to the delta plain subfacies,with an average porosity of 15.85%and an average permeability of 24.63×10^-3?m².Mesoporous low permeability reservoir.The pore structure of the Chang 2 reservoir is complex.The main pore types are intergranular dissolved pores and residual intergranular pores.The pore throat type belongs to medium pore and medium thin throat type.Therefore,the Chang 2 oil layer group can be subdivided into three sub-oil layers of length 2¹,length 2²and length 2³ from top to bottom.The oil layer is mainly concentrated in the long 2¹ oil layer group at the top of Chang 2.The main diagenesis of the Chang 2 oil-bearing formation group has obvious effects on mechanical compaction,cementation,metasomatism,dissolution and rupture.The type of Chang 2 reservoir is mainly IIa and Ib,accounting for 25.66%and 22.74%of the total reservoir,respectively;the second is Ia and IIb,accounting for 16.62%and16.62%of the total reservoir,respectively.Class IIIa accounts for 10.79%,and Class IIIb and Type IV are rare.For the Chang 2 reservoir,the permeability is less than 1×10^-3?m²,which is the non-effective reservoir,that is,the III+IV type belongs to the non-effective reservoir,and the I+II effective reservoir accounts for 81.63%of the total reservoir.These two types of reservoirs are the main reservoirs in the study area.The main controlling factors of reservoir performance in this area are sedimentary microfacies,tectonic and diagenesis.The development of source rocks,the supply of sufficient oil sources,and the development of nasal structures make the area a favorable place for high oil and gas enrichment.