摘要
鄂尔多斯盆地致密砂岩储层具有填隙物含量高、孔隙狭小、物性差等特点,可动流体饱和度是评价致密砂岩储层的关键参数。为研究致密砂岩储层可动流体特征,利用核磁共振实验,对鄂尔多斯盆地姬塬地区长7段致密砂岩进行测试,结果表明不同的T_2值对应不同种类的流体,低T2值对应微孔隙中黏土束缚流体,中T_2值对应小孔隙中毛细管束缚流体,而高T_2值对应大孔隙中的可动流体,T_2图谱可以反映样品中可动流体分布情况。研究区长7段致密砂岩可动流体T2图谱以单峰型和左峰高右峰低型为主,相比于盆地其他层位的特低渗储层T_2图谱分布,致密砂岩储层单峰型较多,右峰高左峰低型和左右峰基本相等型较少。可动流体饱和度分布范围较大,平均值为41.3%,在鄂尔多斯盆地属于中等范围,但可动流体饱和度大于50%的仍占37.9%,可动流体饱和度较高区域是寻找油藏有利区的主要方向。
Movable fluid saturation is the key factor to evaluate the potential of tight sandstone reservoir.It has characteristics of high content of interstitial material,pore narrow and poor physical property in Ordos Basin.To research the movable fluid of tight sandstone,this article uses NMR to test samples of tight sandstone in Jiyuan area of Ordos Basin.Result shows that different T2 corresponds to different types of fluid,low T2 corresponding to fluid restricted by clay bound,middle T2 corresponding to fluid restricted by capillary in micro pore,and high T2 corresponding to free movable fluid in macro pore.Then,the T2 map could reflect distribution of movable fluid of samples.In the research area,most movable fluid T2 maps of tight sandstone are single-peak type and high-left-peak type,contrastive to T2 maps of other formations with extra-low permeability.The single-peak types are more,and high-right-peak types and equal peak types are less.The distribution range of movable fluid is relatively wide,and the average is 41.3%,which belongs to medium in Ordos Basin,while movable fluid saturation above 50%still has 37.9%,and the area of high movable fluid saturation is the main direction to find favorite area.
出处
《地质科技情报》
CAS
CSCD
北大核心
2017年第1期183-187,共5页
Geological Science and Technology Information
基金
国家重大科技专项(2008zx05013-005)
