关键词: 滑塌浊积岩, 储层对比, 隐蔽油藏, 储层预测, 勘探技术, 东营凹陷

Abstract:

Fluxoturbidite is the product of redeposition of frontal sheet sand or river mouth bar sandbodies, which avalanche and slide when the external shearing force triggered by gravity and earthquake overcome the internal cohesive force. It is characterized by siltstone and fine sandstone with good sorting and relatively high tex-tural and compositional maturities. According to the areal development characteristics of turbidite, it can be basically divided into two types, namely non-channelized and channelized turbidites. The conventional sedimentary cycle correlation and high resolution sequence stratigraphic correlation technologies are not applicable in fluxoturbidite areas, due to their unique genesis. Well data and seismic data should be integrated to recognize large stratigraphic boundaries and marker beds and realize strata correlation step by step. Fluxoturbidite reservoirs are dominated by micropores and are of moderate to low porosity and low permeability reservoirs; the average porosity of single layer is generally below 23%, and the average permeability is less than 50×10^-3μm². Evaluation of fluxoturbidite reservoirs should be focused on the areal continuity, connectivity, thickness and oil-bearing properties of sandbodies. Fluxoturbidite reservoirs have been deposited in deep lake near the rich source rocks. Hydrocarbons would migrate vertically, laterally or along faults in short distance and accumulate in lithologic and lithologic-fault screened traps. Sedimentary microfacies analysis and seismic inversion are commonly used for reservoir prediction during exploration of fluxoturbidite reservoirs. Based on the results of reservoir prediction, 11 targets are presented for exploration of fluxoturbidite subtle reservoirs.

Key words: fluxoturbidite, reservoir correlation, subtle oil reservoir, reservoir prediction, exploration technology, the Dongying sag