Abstract:

3 types(including 10 kinds)of reservoir bodies are discovered by means of seismic stratigraphy in the Tertiary strata in the Jizhong Depression.The first type are high energy reservoir bodies which deposited rapidly in the environment of higher hydrodynamic energy or gravity energy.This type of reservoir bodies generally have particular forms and reflective textures of the seismic facies.For instance,the seismic response of deep-water fans are high amplitude-mound facies,the shellow-water fans are draping facies with imbricated texture ininternal reflection,the alluvial fans are low amplitude-mound facies,the deltas are oblique foreset facies and the colluvlal cones are chaotic moundfacies.The second type are geomorphic reservoir bodies which were controlledby paleogeomorphology.The seismic reflectance of slope washes are generally discontinuous high amplitude facies in the form of pancake or wedge and the filled sand and conglomerate bodies are filling facies with concave-down baseplates and the arcual top surfaces.The third type are reservoir bodies with special lithology.The seismic reflectance of volcanic rock reservoirs are cha-racterized by high amplitude,low frequent,fine continuity and high layervelosity and the carbonate rocks are mainly determined by their thickness and stability,when the rocks are thin,dispersed and less stable,seismic reflec-tance will occur contortion and branch;when the rocks are thick and continu-ous,the properties of reflectance will show a high wave and a low wave withlight-undulatory contortion.The above reservoir bodies were controlled by paleo-current direction,strengh and paleogeomorphology as well as tectonic move-ment.