砂岩孔隙度演化定量模拟方法——以鄂尔多斯盆地镇泾地区延长组为例  

Quantitative simulation of sandstone porosity evolution:A case from Yanchang Formation of the Zhenjing area,Ordos Basin

作　　者：潘高峰[1] 刘震[1] 赵舒[2] 胡宗全[3] 胡小丹 

机构地区：[1]中国石油大学油气资源与探测国家重点实验室,北京102249 [2]中国石化华北分公司勘探开发研究院,河南郑州450006 [3]中国石化石油勘探开发研究院,北京100083 [4]中国石油东方地球物理公司油藏地球物理研究中心,河北涿州072751

出　　处：《石油学报》2011年第2期249-256,共8页Acta Petrolei Sinica

基　　金：国家科技重大专项(2008ZX05002)资助

摘　　要：在地层埋藏史和成岩史研究的基础上,综合考虑破坏性成岩作用和建设性成岩作用对孔隙度的影响,按照效应模拟原则,以现今孔隙度特征为切入点,以地史时间为主线,把孔隙度演化分为孔隙度减小和孔隙度增大两个独立的过程,通过增孔和减孔效应叠加建立砂岩孔隙度演化的数学模型。本文建立的砂岩孔隙度演化模型方法有以下特点:①以时间为变量,体现孔隙度演化的动态过程;②以现今孔隙度特征为边界条件进行约束,结果可靠;③综合考虑压实作用、胶结作用和次生溶蚀作用的影响。通过对镇泾地区长8砂岩孔隙度演化的模拟发现:其孔隙度减小过程模型是对埋深和埋藏时间的连续函数;次生增孔缘于有机酸的溶蚀作用,增孔作用受溶蚀强度的影响,主要发生在70～90℃的温度窗口内,增孔过程分为增孔前、增孔窗口内和次生孔隙保持阶段。分段模型叠加得到的总孔隙度演化模型是一个三段式的分段函数。实际应用表明该方法在砂岩古孔隙度计算及孔隙度演化模拟方面有较好的应用效果。The present paper presented a newly developed quantitative simulation for sandstone porosity evolution.The methodology was based on burial history and diagenetic history of strata.The impact of both destructive and constructive diagenesis on porosity was taken into account.With effect-oriented simulation as the principle,geological time as the variable,and current porosity as boundary contraint conditions,the porosity evolution was divided into two independent processes： porosity decrease and porosity increase,for which two mathematical models were built,respectively.Then,a mathematical model was established based on the superimposition of two types of porosity evolution processes.This porosity evolution model was characterized by： 1） time as the variable that reflected the dynamic process of porosity evolution;2） current porosity as boundary constraint conditions whose results were reliable;3） full consideration of the impact of compaction,cementation and secondary dissolution.The mode was applied to simulating the porosity evolution of the Member 8 of the Yanchang Formation in the Zhenjing area in the Ordos basin,and it was found that the decrease in porosity was a continuous function of burial depth and burial time;and that the secondary porosity was caused by organic acid dissolution within a temperature window of 70℃～90℃.The porosity increase included three stages： pre-porosity increase,porosity increase under temperature window conditions,and secondary porosity preservation.The total porosity evolution model built from the superimposition of porosity decrease and increase was a piecewise function with three sections.The application of this approach indicated that it could be widely used in paleoporosity restoration and porosity evolution simulation.

关 键 词：鄂尔多斯盆地 效应模拟 成岩作用 次生孔隙 古孔隙度 孔隙度演化 

分 类 号：TE112.23[石油与天然气工程—油气勘探]