潜山型储层纵向分带测井表征方法及应用

Logging characterization method and application of vertical zonation of buried hill reservoir

潜山型油气藏是中国化石能源勘探的持续增长点,其极强的非均质性给优势储层空间展布规律研究带来较大困难。为统一表征不同类型潜山纵向分带,实现优势储层预测,从岩石物理角度出发,依据储层受地质作用改造程度,潜山型储层纵向上可以划分为强改造带、改造带和未改造带三大相带。在此基础上,基于潜山发育模式及沉积演化过程,进一步细分为风化破碎带、垂向连通带、过渡带、水平连通带和原生带5个亚带。在提炼归纳潜山型储层电性和孔隙特征差异的基础上,利用测井信息计算得到孔隙度谱峰表征系数、声法裂缝表征系数及综合表征系数,构建了潜山型储层纵向分带的测井表征方法。利用上述方法在新疆、南海等地区潜山型储层中建立了纵向分带测井划分标准,应用结果表明,风化破碎带、垂向连通带和水平连通带为优势储层发育区带,塔北地区优势储层发育区带的平面展布规律为自东北向西南方向风化破碎带厚度先增大后减小、垂向连通带厚度逐渐减小、水平连通带厚度逐渐增大。

Buried hill type oil and gas reservoir is a continuous growth point of reserves in fossil energy exploration in China.However,the extremely strong reservoir heterogeneity brings great difficulties to the study of spatial distribution of dominant reservoirs.From the perspective of petrophysics,the buried hill type reservoir is classified into strong transformation zone,transformation zone and nontransformation zone in vertical direction based on the degree of reservoir transformation,so as to characterize the vertical zoning of different types of buried hills and predict the dominant reservoir.Furthermore,it is subdivided into five sub-zones based on the buried hill development pattern and sedimentary evolution process,i.e.,weathering fractured zone,vertical connecting zone,transition zone,horizontal connecting zone and primary zone.The differences of reservoir electrical properties and pore characteristics are summarized and the logging characterization method of vertical zonation of buried hill type reservoir is constructed by using porosity spectrum,acoustic fracture and comprehensive characterization coefficients calculated by logging information.The above method is used to establish the classification standard for vertical zonation of buried hill type reservoirs in Xinjiang,South China Sea and other regions.The application results show that the weathering fractured zone,vertical connecting zone and horizontal connecting zone are favorable for the development of dominant reservoir.The plane distribution law of the dominant reservoir in Tabei area shows that,from northeast to southwest,the thickness in the weathering fractured zone increases first and then decreases,that in the vertical connecting zone decreases gradually,and that in the horizontal connecting zone increases gradually.