Research On Logging Identification Method Of Chang 7 Effective Reservoir In The Jingan Area

The Chang-7 reservoir in Jing'an area is a lithologic reservoir controlled by the distribution of source rocks.At present,the proportion of Chang-7 production and production in Jing'an District has gradually increased.However,because of the differences in deposition and diagenesis of each stratum in the Yanchang Formation,the accumulation rules of oil reservoirs are different,showing different logging response characteristics,and resulting in the identification of oil and water layers.difficult.The distribution of oil and water is unclear and production and construction are difficult to carry out.Therefore,in the current situation of exploration and development,it is urgent to carry out the second fine interpretation of well logging and re-identify the oil and water layers.This paper takes the Chang-7 reservoir in Jing'an area as the analysis objective,and carries out stratigraphic division and comparison.It analyzes the characteristics of the plane distribution of sedimentary microfacies and establishes an interpretation model for each parameter of the reservoir.For different types of reservoirs,the plates are used separately.The oil and water layers were identified by the method,the array induction resistivity intrusion analysis method,the acoustic wave time difference and resistivity overlay map method and the apparent resistance increase rate method.Obtained the following understanding:?1?The sedimentary environment of the Chang-7 reservoir in the Jing'an area is relatively stable,and the structural features of the top layers of the small layers are similar.The slope is basically west inclined,but some low-profile row noses are formed on a relatively flat geographical background.Pleated structure;the source is northeast,and Chang-7 is the delta front sedimentary sub-environment,and the sedimentary microfacies are mainly submarine distributary channel microfacies.?2?The debris components of the Chang-7 reservoirs in Jing'an area are similar,with clastic feldspar and feldspar sandstones as the main components.There are many types of interstitial materials,intergranular pores dominate in pore types,and pore throats are relatively well-sorted,but overall analysis of the physical properties of Chang-7 reservoirs is common.Through the standardized processing of logging data,the accuracy of logging data is improved to ensure the accuracy of logging interpretation.The relationship among reservoir lithology,physical properties,electrical properties,and oil-bearing properties was studied,and the parameter interpretation model for the Chang-7 reservoir was defined.The lower limit of the physical property was determined,and the lower limit of porosity was 6.5%.The degree-permeability composite intersection chart confirms that the lower limit of permeability is 0.08×10^-3?m².?3?It is difficult to identify the oil layer and oil-water layer in the study area.According to the different formations,the plate,the array induction resistivity intrusion analysis method,the acoustic wave time difference and the resistivity overlap chart method,and the apparent resistance increase rate method were used to identify the oil and water layer in the whole area,and good results were obtained.Through fine interpretation of well logs,a total of 149 wells were interpreted in the Chang 7 strata in Jing'an area with a cumulative thickness of 784.8 m and an average effective well thickness of 5.2m.The log interpretation results for 24 wells were improved,cumulative oil reservoirs were added,and Oil thickness of the same layer116.5m.