塔中北坡鹰山组碳酸盐岩缝洞体量化描述技术及应用

Application of Fracture-Cave Quantitative Technique for Carbonate Reservoir of Yingshan Formation of Lower Ordovician in North Slope of Tazhong Area,Tarim Basin

针对各种储集层地质模型,根据野外观测系统和工区地震地质条件,利用Tesseral全波场模型正演方法,明确高产井有利储集体地震响应特征。通过大量的正演研究,分析各种储集层的地球物理响应特征,优选出波阻抗反演地震属性预测方法,将校正后的波阻抗体转换为孔隙度体,可得储集层的有效储集空间,最终实现岩溶缝洞体有效储集空间的量化描述。研究表明,"表层强且内幕规则串珠反射"、"表层弱且内幕强串珠反射"是高产高效井的主要表现形式。下奥陶统风化壳碳酸盐岩储集层的地震响应特征为低阻抗、低速度、低频、强分频振幅、强相干、强衰减等特征。经缝洞体量化描述,中古8井储量区有效储集层总体积为5.42×108 m3.勘探实践表明,量化描述缝洞体是碳酸盐岩油气藏高效勘探开发的有效途径之一。

In view of geologic models for various reservoirs,integrated with field observing system and seismic geologic conditions in studied area,the numerical simulation is conducted using Tesseral forward software,and the seismic response characteristics of favorable reservoir in highly producing wells.The predicting method for wave impedance inverse seismic attribute is selected through forward studies,analyses of the geophysical response characteristics of all kinds of reservoirs.The corrected wave impedance data body is converted into the porosity data body,followed by getting the effective reservoir spaces of the reservoirs and finally realizing the quantitative description of the effective reservoir spaces.The study shows that highly producing and effective wells are characterized by seismic features of ＂strong surface plus inside regular beads reflection＂ and ＂feeble surface plus inside strong beads reflection＂.The seismic response characteristics of the carbonate reservoir of the Lower Ordovician weathered crust are dominated by low wave impedance,low velocity,low frequency,strong frequency-division amplitude,strong coherent and intensity attenuation,etc.Through the fracture-cave quantitative sculpture,the total effective reservoir volume is 5.42×108 m3 in Block Zhonggu-8.Exploration practice indicates that the quantitative sculpture of fracture-cave in carbonate reservoir is one of the effective methods to improve the exploration success rate.