0 引言
1 地质背景
2 样品及分析方法
表1 志靖—安塞地区长8段典型致密砂岩样品基本信息及物性特征Table 1 Basic information and physical properties of typical tight sandstone samples from Chang 8 Member in Zhijing-Ansai areas |
井号 | 深度/m | 层位 | 岩性 | 孔隙度/% | 渗透率/(10-3 μm2) |
---|---|---|---|---|---|
G122 | 2 058.70 | 长8段 | 细砂岩 | 8.57 | 0.100 |
X318 | 2 124.77 | 长8段 | 细砂岩 | 6.93 | 0.097 |
D130 | 1 668.05 | 长8段 | 细砂岩 | 4.21 | 0.048 |
X410 | 1 993.90 | 长8段 | 细砂岩 | 3.64 | 0.019 |
3 储层岩石学特征
4 微观孔喉结构特征
4.1 储集空间类型及特征
图4 研究区长8段致密砂岩储层孔隙类型及压汞曲线特征(a)残余粒间孔,Y19井,1 168.40 m,(-);(b)残余粒间孔,Y19井,1 168.40 m,SEM;(c)残余粒间孔压汞曲线,G122井,2 058.70 m;(d)粒间溶孔,X318井,2 124.77 m,(-);(e)粒间溶孔,X318井,2 124.77 m,SEM;(f)粒间溶孔压汞曲线,X318井,2 124.77 m;(g)粒内溶孔,D130井,1 668.05 m,(-);(h)粒内溶孔,D130井,1 668.05 m,SEM;(i)粒内溶孔压汞曲线,D130井,1 668.05 m;(j)伊/蒙混层晶间孔,X410井,1 993.90 m,SEM;(k)伊/蒙混层晶间孔,X410井,1 993.90 m,SEM;(l)晶间孔压汞曲线,X410井,1 993.90 m Fig.4 Pore types and mercury injection curve characteristics of tight sandstone reservoir of Chang 8 Member in the study area |
4.2 孔喉大小及分布特征
4.3 孔喉连通性特征
5 微观孔喉结构对储层含油性的控制
5.1 孔喉半径分布与储层含油性
图10 研究区长8段致密砂岩储层区间孔喉分布频率总和与含油性相关性分析(a)区间孔喉分布频率总和与含油饱和度相关性,R<0.01 μm;(b)区间孔喉分布频率总和与含油饱和度相关性,0.01 μm< R <1.0 μm;(c)区间孔喉分布频率总和与含油饱和度相关性,R>1.0 μm;(d)储层TSF荧光强度,0.01~1.0 μm孔喉区间频率72%;(e)储层TSF荧光强度,0.01~1.0 μm孔喉区间频率60%;(f)储层TSF荧光强度,0.01~1.0 μm孔喉区间频率40% Fig.10 Correlation analysis between summation of pore throat distribution frequency and oiliness in tight sandstone reservoir of Chang 8 Member in the study area |
5.2 孔隙喉道相对比例与储层含油性
表2 研究区长8段致密砂岩储层样品孔喉体积比计算结果Table 2 Calculation results of pore throat volume ratio of tight sandstone reservoir samples of Chang 8 Member in the study area |
井号 | 深度/m | S max/% | S r/% | V r |
---|---|---|---|---|
Y19 | 1 176.80 | 84.80 | 53.13 | 1.68 |
D130 | 1 668.05 | 74.50 | 56.06 | 3.04 |
S268 | 1 739.40 | 79.00 | 63.14 | 3.98 |
S268 | 1 795.85 | 85.80 | 71.38 | 4.95 |
S165 | 1 975.20 | 73.70 | 52.65 | 2.50 |
X410 | 1 993.90 | 70.30 | 44.03 | 1.68 |
X410 | 1 994.70 | 84.70 | 67.93 | 4.05 |
G122 | 2 058.70 | 86.20 | 69.01 | 4.02 |
G122 | 2 061.75 | 51.20 | 36.50 | 2.48 |
G122 | 2 065.60 | 73.60 | 49.43 | 2.05 |
X318 | 2 124.77 | 79.10 | 55.91 | 2.41 |
X318 | 2 125.22 | 89.40 | 66.62 | 2.92 |