The Research On Reservoir Of Chang8₂Formation In Dingbian Area

Based on predecessors’ achievements, logging data, the core analysis test data and variousexperimental data of target area, combining the experimental data, the paper firstly finishessmall layer division and correlation of Chang82in Ding Bian area, secondly analysessedimentary facies, sand distribution regulations and reservoir microscopic characteristics.Thirdly, combining diagenetic facies and reservoir macroscopic and microscopiccharacteristics in target area, established a reservoir classification evaluation standard, anddivided into small layers of reservoir evaluation. Finnally, under the guidance of law, reservoirevaluation target of Chang82in Ding Bian area is displayed.The study shows that: Chang82reservoir strata changes unconspicuous, which can besubdivided into Chang821and Chang822. The top layer structure is presented thecharacteristics of high-east and low-west, developes several nose-like structure from east towest. The delta front deposit dominates the target formation. The main reservoir rock type isfeldspar-debris sandstone and lithic-feldspar sandstone with the characteristics of ultrafine-fineparticle size, intergranular pore, feldspar dissolution pore and small-pore micro-throat andmesopore-micro-throat in Chang82reservoir sandstone. The diagenetic facies can be dividedinto five types in Ding Bian area，the favorable diagenetic facies are Chlorite thin film-residualintergranular pore facies and feldspar dissolution-residual intergranular pore facies. The studyarea is ultralow permeability reservoir, and dominates the characteristics of low porosity andstrong heterogeneity. Combining quantitative description and qualitative description, Chang82reservoir can be divided into four categories, The study result can provide geology referencesfor the future exploration of Chang82stratum in Ding Bian area at last.