Sub-layer correlation by step control well-to-seismic integration.

The sedimentary environment in Tazhong 4 oilfield is the paralic facies,which makes the sub-layer correlation very difficult, and the resolution of the traditional correlation methods cannot sat-isfy the requirement of fine reservoir description.So the sub-layer correlation by step control well-to-seismic integration is proposed. First,based on fine well-to-seismic calibration,isochronal layer structure was established through seismic and datum bed control; Then,the sand sets were correlated in stratum framework by using phase sequence grading rules,sedimentary cycles and inversion re-sults;Finally,single sand bodies were correlated by using model, lithology and thickness ratio.In Tazhong 4 oilfield,33 single sand bodies from 4 sand sets in CI oil set of 37 wells were correlated and delineated through this method.On the basis of this,a suitable correlation scheme and a sub-layer delineation data sheet are estab-lished.