碳酸盐岩缝洞系统地震响应特征分析和塔中卡1区缝洞储层预测

碳酸盐岩岩溶风化壳由多期喀斯特化与后期构造运动叠加改造的孔、洞、缝等组成，形成了大小不等、空间形态复杂的储集体，此类储层非均质性强，难以预测和表征。设计了不同尺度溶洞和裂缝的碳酸盐岩岩溶风化壳物理模型，采用超声定比观测方法对地震波的传播能量和反射结构变化进行了分析。结果表明，理想条件下溶洞与裂缝可形成强短反射和杂乱反射，极不规则溶洞和洞缝的复杂联合体均表现为反射背景上的杂乱反射。利用强振幅聚类分析和不连续性检测等手段对塔中卡1区的叠后地震资料进行了储层预测和识别，卡1区的碳酸盐岩岩溶缝洞型储层表现出强短反射和反射背景上的局部杂乱反射这2种地震微相。利用古构造起伏趋势和波形检测等辅助方法，进一步证实了这些反射异常与卡1区岩溶缝洞地质成因的关联性。综合分析认为，卡1区碳酸盐岩岩溶缝洞型储层发育程度较弱，在构造高点部署的2口异常区外的探井实钻数据也证实了这一预测结果。

Seismic response and prediction of fracture-cavity system in carbonate reservoir:A case study in the Ka-1 field

The weathering crust in carbonate rocks, which usually suffered from multi-period polycycle karstification and structure deformation, is heterogeneous reservoirs that are rich in pores, fractures and caverns.The reservoirs,diversified in scale, space configuration and complex in buildup, are difficult to be predicted and described. The observations in ultrasonic models, which reflected the seismic response characteristics of caverns and fractures in the condition of ideal, opened out that the former behaves the short strong reflect energy, the later the seismic clutter facies. A majority of fracture-cavity systems, included irregularity in shape and close in scale, appear the clutter facies in the background of reflection. In terms of the clustering technique for strong amplitude and the discontinuity detecting technique for clutter reflective facies, the two typical response characteristics can be recognized from seismic data in Ka-1 field. At the same time, the abnormal are further confirmed to correspond with the possible karst fracture-cavity reservoirs in geology cause of formation by dint of the assistance methods such as the pole-structure compensation technique and waveform clustering analysis about seismic micro-facies. The cross-verification of the estimated results makes clear that the karst fracture-cavity reservoirs in Ka-1 field are soft and located in the flatness region from well Z1 to Z11. The conclusion is also confirmed by two wells out of abnormal, which are located the high positions of two structural traps and are poor reservoirs.