Research On Reservoir Characteristics Of Cretaceous-Paleogene In Fangzheng Fault Depression

According to using the theories and techniques of reservoir geology, modern sedimentology, sequence stratigraphy and reservoir evaluation to research thoroughly the feature of lithology, the distribution of sand body, lithogenesis and the physical property of the clastic reservoirs, started from the regional geology background of the whole sediment basin and its ancient geology location,based on the information of core, logging, drilling, testing data.Drawing triangular diagrams of the reservoir rock types based on the research of lithology feature which is obtained from the study to wafer data and core wafer. From the triangular diagrams, feldspar sandstone and lithic arkose are the main lithologies, this is beneficial to generate secondary pores; Compositional maturity and texture maturity are both low. The general class of reservoir is middle-fine sandstone. The general shimming materials are carbonatite and mud. From the calculated datum of core physical property,the porosity and the permeability is both low, so the reservoir is from especially low porosity and especially low permeability. According to the analysis of wafer and scanning electron microscope, the secondary pores are the main pore type of cretaceous-paleogene, the second ones are splits, inflexible ompation, ementation, uartz overgrowth, metasomasis and dissolution are the main diagenesis types. According to the analysis of diagenesis, cretaceous-paleogene's the diagenetic stage basically entered in the middle diagenetic stage A1, or even to enter in the middle diagenetic stage A2. The second pore growth degree is mainly influenced by cementation, quartz, feldspar and diffluence. Forecast the distribution of sand body, on the basis of logging, drilling, testing data.Finally combining the research and understanding of the regional reservoir distribution, physical groperty variation, diagenesis evolvement, pore structure, etc, generally evaluate the advantageous fades belt and advantageous reservoir distribution, which will be a good scientific guidance to improving the oil and gas eiploration.