HIGH-RESOLUTION SEQUENCE STRATIGRAPHY AND SANDBODY DISTRIBUTION IN THE PUTAOHUA RESERVOIR OF THE SANZHAO SAG

Using high-resolution sequence stratigraphy theory, We analyzed 22 drill cores and 4256 well log data, in order to characterized the sedimentary squence and base-level cycls in the Putaohua reservoir of the Sanzhao Sag. The Putaohua reservoir includes two medium-term base-level cycle, four short-term base-level cycles, and eight super-short-term base-level cycles. Thus a high-resolution sequence stratigraphic framework has been established. The Putaohua reservoir is controlled by syn-depositional uplifting which resulted in the southward thinning of the super-short-term base-level cycles. From the northwest to the south in the Sanzhao Sag, the upper sandstone body in the Putaohua Reservoir offlaps northward and is gradually replaced by muastone in the southern part of the Sag the Lower sandstone body of the Putaohua reservoir onflaps southward and is gradually replaced by mudstone in the southern part of the Sag.