XC地区茅口组岩溶储层发育有利区预测

Prediction of favorable development area of Maokou Formation karst reservoir in XC area

前人常利用储层的“暗点”“亮点”技术,预测茅口组岩溶储层和指导勘探布井,但在实际生产中,“暗点”“亮点”特征受岩性等多种因素的影响,具有不确定性。为了明确四川盆地XC地区茅口组岩溶储层发育特征,文中利用XC地区三维地震资料,在分析茅口组储层地震响应特征的基础上,开展了沉积相带预测、古地貌恢复和属性提取,对研究区岩溶储层发育有利区进行了预测。研究表明:茅口组上部储层发育时,茅口组顶界具有弱振幅“暗点”特征,茅口组顶界之下的波谷具有振幅减弱的地震响应特征;当茅口组内部泥质含量增加时,也会出现“亮点”特征,需要结合沉积相综合分析;茅口组岩溶储层的发育主要受沉积相、古地貌和断裂等因素的综合控制。

Previous researchers often use"dark spot"and"bright spot"to predict karst reservoir of Maokou Formation and guide exploration well layout,but in practices,we often found there are many explanations for"dark spot"and"bright spot",which are affected by lithology and other factors.In order to make clear the development characteristics of Maokou Formation karst reservoir in XC area,based on the analysis of seismic response characteristics of Maokou Formation reservoir in XC area by the 3D seismic data,the prediction of sedimentary facies belt,restoration of paleogeomorphology and extraction of sensitive attributes were carried out to predict the favorable area of karst reservoir development.The results show that:when the reservoir at the top of Maokou Formation is developed,the top boundary of Maokou Formation has the response characteristics of weak amplitude"dark spot",and the wave trough under the top boundary of Maokou Formation has the response characteristic of weakening amplitude;when the content of mud in Maokou Formation increases,there will be"bright spot"indication,which needs comprehensive analysis with sedimentary facies;the development of karst reservoir is mainly controlled by sedimentary facies,palaeogeomorphology and faults.