MESOZOIC RESERVOIR IN CHENGDAO AREA AND ITS CONTROLLING FACTORS

The Mesozoic is the next exploration target in the Chengdao area. Effective reservoir prediction is the key to successful exploration. In order to reveal the controlling factors of the Mesozoic reservoir, reservoir types and their physical features are studied using cores and well logs. Results suggest that there are two kinds of reservoirs, say, clastic rock and volcanic rock. Secondary pores predominate. The distribution of reservoir physical parameters is heterogeneous and controlled by lithology, unconformity, faulting and diagenesis. Porosity and permeability are the major lithological parameters which decrease in an order of pebbly sandstone, sandstone, siltstone, conglomerate and volcanic rock. In terms of unconformity and fault, the influence is restricted in a distance of 100m. For same reservoir lithology, the shorter the distance between the reservoir and unconformity and/or fault, the higher the porosity and permeability of the reservoir.Diagenesis plays important roles to the formation of secondary pores.