摘要
随着勘探程度的提高,油气勘探必然向深层延伸。弄清深部储层的孔隙演化规律,提高预测精度,是深入勘探的重要基础。通过对柴达木盆地昆2井岩屑和岩芯样品的系统采集,运用铸体薄片、扫描电镜和测井解释等手段,系统分析了古近系与新近系地层的岩石学、矿物学和储层物性特征,发现泥质杂基含量与砂岩的孔隙演化密切相关。为了正演孔隙的演化过程,运用分选很好的风成石英砂和粒度细小的红色粘土为材料,按照粘土杂基含量为5%、10%、15%、20%,制作了四类石英砂开展模拟实验。松散沉积物的压实模拟,从1.4MPa试验加压到210.4MPa,分别进行了21个循环实验。将实验模拟的结果,与昆2井的岩芯资料进行了对比分析。研究表明,碎屑岩泥质杂基含量越高,初始孔隙度越小,孔隙度衰减越快;泥质含量较低的净砂岩,当上覆压力达到76.5MPa时,颗粒大量破碎并重新排列,导致粒间体积减缩以及少量直线型粒内裂缝出现,储层物性明显变差。压实模拟的实验数据,能够为快速沉降区砂岩的储层质量预测提供依据。
With the enhancement of exploration extent,deep oil——gas exploration is inevitable. It's imperative to figure out the law of porosity evolution of deep reservoirs as well as to raise forecast accuracy,which is the basis of deep exploration. Through systematic collection of cuttings and core samples from Well kun-2,Qaidam Basin and using casting thin sections,scanning electron microscope and logging data interpretion,the characters of petrology, mineralogy and physical properties of reservoirs in both Paleogene and Neogene stratums are systematically analysed. As a result,the content of argillaceous matrix and the porosity evolution of sandstones are closely related. In order to complete the forward modeling of the process of porosity evolution,well-sorted aeolian quartz sands and the fine-grained red clay are chosen as materials,and four kinds of quartz sands are made respectively containing clay matrix of 5%,10%,15%,20% to carry out the simulation. Unconsolidated sediments compaction simulation was carried out from 1. 4 MPa to 210. 4 MPa,containing 21 cycle experiments respectively. The results of stimulant experiment against the core data of Well kun-2 under a comparative analysis shows that the much higher the content of argillaceous matrix in clastic rocks was,the smaller the primary porosity would be and the faster the porosity would decay; for arenite with low argillaceous content,when the overburden pressure reached 76. 5MPa,a large number of particles were broken and rearranged,which led to intergranular volume reduction and occurrence of few linear intragranular fractures,meanwhile the reservoir physical properties significantly worsen. The experimental data of compaction simulation can provide a basis for the reservoirs quality prediction of the sandstones in rapid subsidence area.
出处
《地质论评》
CAS
CSCD
北大核心
2015年第6期1447-1457,共11页
Geological Review
基金
国家自然科学基金资助项目(编号41402101
51404136)的成果
关键词
柴达木盆地
泥质杂基
压实模拟
储层质量预测
Qaidam Basin,argillaceous matrix,compaction simulation,reservoir quality prediction
