Research On Characteristics Of Chang6Section In West Fuxian-Huangling Exploration Area

Fuxian-Huangling exploration area, main body in Shaanxi province is located in the south of Yanan city in Fuxian and Huanglingxian. In the areal struture, It is located in Erdos Basin in the southern part of the northern Shaanxi’s slope. In this article the research area of FuHuang prospecting area’s western, Huai6-Huangcan38is the focus area, the local development of nose uplift. Now with the FuHuang prospecting area in western Huai6-Huangcan38well field of petroleum prospecting obtains major breakthrough, have more attracted attention.In this thesis, using stratigraphy, sedimentology, petrology, reservoir geology, petroleum geology and other aspects of the theory and research of evaluation technique, based on the static, dynamic and analysis and test data to develop FuHuang prospecting area’s western Chang6reservoir characteristic research. Through the research of Chang6section of subfacies division and correlation, further research shows that the Chang6section of delta front subfacies block-heavy bedded sand body upgrowth, locally formed delta front underwater slump turbidite fan, middle fan development is characteristic of it, Chang61, Chang62, Chang63three subgroups of sedimentary facies plane distribution features are basically similar; reservoir sandstone is mainly chondro arcose and a very small amount of chondro syrosem arcose, its compositional maturity and textural maturity was low, mechanical compaction and cementation reduces the porosity, permeability, dissolution improve reservoir physical property, metasomatism of the reservoir has little effect on overall. Reservoir average porosity is7.8%, the mean permeability of0.33×10-3μm2, belongs to ultra low porosity and ultralow permeable sublayer, from Chang63,Chang62to Chang61, property has an overall good trend; The reservoir main pore types has intergranular pore, feldspathic dissolved pores,detrital dissolved pore and microfracture. Poreous combination from middle to small and from fine to tiny throat mainly; The chang6of each subgroup is similar between heterogeneity; The Chang6in northeast-sorthwest and northwest-sortheast to the fractures are most developed, and the main development of tectonic microfracture; The Chang6reservoir four properties relationship is obvious.The Chang6reservoir evaluation thought, the reservoir can be divided into4categories, The class Ⅰ (good reservoir), Ⅱ (better reservoir), Ⅲ (medium reservoir), Ⅳ (poor reservoir), with class Ⅲ is main reservoirs. The reservoir quality is relatively, Chang61is the best, Chang62is the middle, Chang63is the worst.