应用压实曲线法评价东濮凹陷泥岩盖层封闭能力  

Evaluation of Cap Rock Sealing Capability of Mudstone in Dongpu Depression by Using Compaction Curve

作　　者：高平[1] 段红梅[1] 王兴武[1] 夏宝华[2] 

机构地区：[1]中国石化中原油田分公司勘探开发科学研究院 [2]中国石化中原油田分公司采油二厂,河南濮阳457001

出　　处：《中外能源》2007年第1期35-39,共5页Sino-Global Energy

摘　　要：东濮凹陷的一大特点是其北部纵向上发育4套盐岩,它们构成油气富集的优良盖层。东濮凹陷天然气藏在无盐岩沉积区埋藏深度在3000m以下,并主要分布在3600m以下,与泥岩封闭性能随深度的变化有很大关系。泥岩经压实固结成岩后,其孔隙度变小,从开始具有封闭能力,到封闭能力逐渐变好。而泥岩孔隙度与声波时差值有很好的相关性,因此,泥岩声波时差值与其封闭性之间有着较好的相关性,这是利用泥岩压实曲线定性评价盖层封闭能力的理论基础。通过对东濮凹陷纯泥岩岩样排替压力测试数据与相邻井声波时差值的统计分析,建立回归方程,同时选择不同地区的钻井编制泥岩压实曲线,根据泥岩压实阶段划分及各阶段泥岩时差、排替压力演化特征,建立泥岩盖层封闭能力的分类标准,计算东濮凹陷泥岩的封气门限深度在1500～1900m左右。实践证明其方法简单、快速,适合于勘探程度较高的油气区。A typical feature of Dongpu depression is that 4 sets of halite are vertically developed in the north,which forms the favorable cap of hydrocarbon accumulation.Gas reservoir in Dongpu depression in the area without halite is buried below 3000m,mainly below 3600m,which is greatly related with mudstone sealing capability changing with depth.After its compaction into rock,mudstone has lower porosity and its sealing capability becomes better.Its porosity has good relativity with its interval transit time,so its interval transit time also relates with its sealing capability ,which is the basis for using mudstone compaction curve to qualitatively evaluate cap rock sealing capability.Regression equation has been established after statistically analyzing displacement pressure testing data of pure mudstone sample and interval transit time of adjacent wells. Meanwhile,various wells are selected to compile mudstone compaction curve.According to compaction phases,interval transit time cation standard of 1500 -1900m. Practice of different mudstone has also phases and displacement pressure evolution are plotted out to buildup classificap rock sealing capability.Calculation shows gas sealing threshold is about proven that the method is simplified and quick for the hydrocarbon area with high level exploration.

关 键 词：泥岩盖层 声波时差与排替压力 压实曲线 封闭能力 

分 类 号：P618.13[天文地球—矿床学]