SEISMIC REFLECTION CHARACTERISTICS OF HALITE AND RELATED HYDROCARBON ACCUMULATION TYPES OF THE WENLIU OILFIELD IN THE DONGPU SUBBASIN

The physical properties, seismic reflection features, geometry and halite-related hydrocarbon accumulation types in the Wenliu oilfield of the Dongpu subbasin were studied by using seismic reflection data, combined with geological and drilling data.The studies show that halite is characterized by a constant low density low and a high stable velocity, which in the main do not change with depth.The boundary between halite and areno-argillaceous rocks show distinct reflection features because there is a strong impedance difference between them.However, due to the flow feature, halite has several modes of occurrence and their seismic reflection features are different, which makes it difficult to recognize halite. A discrimination model for halite beds (bodies)has been summarized by using seismic data.There are three main modes of occurrence for halite in the study area:primary platy halite, post-deformational halite and secondary salt wall.The flow deformation and facies change of halite formed three types of hydrocarbon accumulations, namely, graben-type anticlinal accumulations above salt, lateral salt-sealed accumulations and anticlinal accumulations below salt.