查干凹陷砂砾岩体溶蚀孔隙储层测井解释方法

Log Interpretation Method of Chagan Sag Gravel Rock Dissolution Pore Reservoir

查干凹陷下白垩系巴二段是一套近物源、多物源沉积扇体,储层岩屑和长石含量高,非均质性强,物性差,孔隙度和渗透率均较低。受溶蚀作用的影响,储层溶蚀孔隙发育,孔隙结构变化大,声波测井反映孔隙度的能力明显降低,三孔隙度测井曲线响应特征进一步复杂化,大大降低了储层的识别能力和油层的解释精度。针对该区溶蚀孔隙发育的砂砾岩体油藏,在岩心分析的基础上开展溶蚀孔储层岩石物理特征研究,建立测井响应特征模式,形成一套定性识别和定量评价溶蚀孔隙储层的测井评价方法,提高了溶蚀孔隙储层的识别能力,实际资料应用效果良好。

Lower Cretaceous Ba2 Segment of Chagan Sag is a set of near source and multi- provenance sedimentary fan body with high content of reservoir rock debris and feldspar, strong heterogeneity, poor physical property, low porosity and permeability. Due to the erosion, dissolution pore of reservoir has developed, thus, its pore structure has changed greatly, the ability of acoustic logging reflecting porosity has obviously weakened and the response characteristics of three porosity logging curves have become further complicated. Consequently, the identification ability of reservoir and the interpretation accuracy of oil reservoir are significantly reduced. Based on the gravel rock reservoir developed by dissolution pore in this area and the core analysis, the research on the petro-physical character of dissolved pore reservoir is conducted, the characteristic pattern of logging response is established and a set of logging evaluation methods of qualitative identification and quantitative evaluation of dissolution pore reservoir are built. Therefore, recognition ability of dissolution pore reservoir is greatly improved. Finally, this method is verified by excellent practical application.