Geological And Geophysical Comprehensive Research On Guantao Formation And Sha-3 Member In Yongbei Area

In the light of strong reservoir heterogeneity,low acquisition of distribution law of reservoirs and the controlling factors of the reservoir forming, based on the geological, seismic, logging, and other information,guided by multi-subject theory, comprehensive geological studies was carried out in Ng and Es3 formations in Yongbei area. According to the stratigraphic contact relations and the stratum development situation, with the full consideration of the connectivity between reservoir and sandstone, combining coring well data, classification and correlation of the target layers was done based on the lithology、electrical property and rhythmicity under the control of the marker bed. On the basis of fine stratum calibration, structural interpretation for main marker beds in study area was done and the structural maps of the top of Ng4 and the top of Es3 were completed. On the basis of core characteristic analysis, think that Ng formation mainly developed braided river sedimentary facies and Es3 formation developed nearshore subaqueous fan in which the ancient gullies distributing in a large area in the steep slope zone. In the guidance of sedimentary facies, with the technologies of frequency division and seismic attenuation, meticulous depiction of reservoirs in Ng and Es3 was carried out, the distribution and oil-bearing properties of the reservoirs were cleared, the controlling factors and the distribution law of the reservoirs were studied, and the accumulation models of Ng and Es3 in study area were established. The results show that Guan-tao reservoirs’ distribution was mainly controlled by structure and locally controlled by both structure and lithology. And the nose structure in Es3 controlled the distribution of heavy oil, whose enrichment degree and boundary were controlled by the changes in lithology and physical properties.