The Study On Reservoir Of The Chang4+5 Reservoir In Nan 111 Wellblock In The Nanniwan Oilfield

In this paper, the Chang4+5 reservoir in Nan 111 wellblock in the Nanniwan oilfield in the Ordos Basin is the research object, through the study in stratigraphic division, structural features, the feature of the sedimentary fades, sedimentary fades and the sand bodies’ distribution on the plane of the Chang4+5 reservoir, have a detailed study for the main oil-bearing horizon Chang4+5 on the reservoir petrology characteristics, diagenesis and the pore structure, also make a Reservoir comprehensive evaluation.According to the rock types, sedimentary structure, sedimentary cycle, lithology, electrical response characteristics, the logging data, drilling core observation and other methods, to identify that the Chang4+5 reservoir in research area major developed the delta plainsubfacies.Research Chang4+5 sandstone are mainly medium-fine sandstone in gray, celadon and taupe feldspar, the filler content is less and mainly for cement. In the cement are mainly chlorite, calcite and laumonite, followed by illite, quartz and feldspar overgrowth, etc. The holes in sandstone are given priority to primary intergranular pore, feldspar dissolution pore, laumonite dissolution pore, intragranular pore and fracture aperture, the main developed hole structure are small the hole- micro throat and the fine hole-micro throat. The study area is generally in low porosity, low permeability reservoir. through the study that in order to provide the scientific prediction of the geology on expanding exploration and forecasting oil favourable object.