0 引言
1 区域地质概况
2 储层岩石学及储集特征
2.1 岩石学特征
2.2 储集物性特征
2.3 储集空间类型
图4 东部凹陷牛居—长滩洼陷沙三上亚段储层储集空间显微照片(a)长石粒内溶孔、岩屑粒内溶孔和少量的原生粒间孔,牛深2井,3 679.5 m;(b)岩屑粒内溶孔,牛深2井,3 677.9 m;(c)长石粒内溶孔,牛深2井,3 677.5 m;(d)杂基溶孔,牛深2井,3 679.5 m;(e)铸模孔,牛深2井,4 145.5 m;(f)伊/蒙混层晶间孔,牛深2井,4 445.5 m;(g)绿泥石晶间孔,牛深2井,4 444.4 m;(h)微裂缝,牛深2井,3 695.7 m Fig.4 Microscope and SEM images showing reservoir pore type characteristics of sandstone reservoirs in the upper third member of Shahejie Formation in Niuju-Changtan subsag of Eastern Sag |
3 储层成岩作用及演化序列
图5 东部凹陷牛居—长滩洼陷沙三上亚段砂岩储层成岩作用类型及特征(a)碎屑颗粒间呈线接触,牛深2井,3 677.9 m;(b)云母等塑性颗粒挤压变形,牛深2井,3 695.7 m;(c)方解石基底式胶结,阴极发光下亮桔色光,牛深2井,3 682.5 m;(d)方解石基底式胶结,牛深2井,3 677.5 m;(e)白云石交代方解石,牛深2井,3 659.72 m;(f)铁方解石充填粒间孔,牛深2井,3 659.72 m;(g)铁白云石充填粒内孔,牛深2井,3 659.72 m;(h)石英具次生加大,牛深2井,3 677.5 m;(i)石英次生加大中捕获的发蓝白色荧光的烃包裹体,牛深2井,3 659.72 m;(j)自生石英充填粒内孔,牛深2井,4 100.69 m;(k)自生石英和自生高岭石充填粒内孔,牛深2井,3 680.5 m;(l)伊/蒙混层和伊利石充填粒间孔,牛94井,3 913 m;(m)长石溶蚀形成粒内孔,牛深2井,3 659.72 m;(n)岩屑溶蚀形成粒内孔,牛深2井,3 677.9 m;(o)颗粒间杂基发生溶蚀形成溶蚀孔,牛深2井,3 695.7 m;(p)石英颗粒边缘发生溶蚀呈锯齿状,牛深2井,3 676.5 m Fig.5 Diagenesis types and characteristics of sandstone reservoirs in the upper third member of Shahejie Formation in Niuju-Changtan subsag of Eastern Sag |
4 不同类型储层孔隙差异演化过程
4.1 成岩相划分及特征
表1 东部凹陷牛居—长滩洼陷沙三上亚段储层成岩相分类方案Table 1 Classification scheme of diagenetic facies of sand-stone reservoirs in the upper third member of Shahejie Formation in Niuju-Changtan subsag of Eastern Sag |
| 成岩程度判别指标 | IGV/% | 孔隙体积/% | 胶结物含量/% |
|---|---|---|---|
| 强 | 13 | >8 | >10 |
| 中等 | 13~15 | 5~8 | 5~10 |
| 弱 | 15 | <5 | <5 |
图9 东部凹陷牛居—长滩洼陷沙三上亚段储层成岩相类型及特征(a)强压实相,杂基含量高,牛深2井,3 846.1 m;(b)强压实相,颗粒接触紧密,牛深2井,4 100.69 m;(c)强溶蚀相,粒内溶孔发育,牛深2井,3 677.9 m;(d)强溶蚀相,粒间孔隙和微裂缝发育,牛深2井,3 695.9 m;(e)强钙质胶结相,强白云石胶结,牛深2井,3 846.4 m;(f)强钙质胶结相,强方解石胶结,牛深2井,3 847.3 m;(g)中等成岩相,压实、胶结和溶蚀程度中等,局部见粒间溶孔,牛深2井,3 682.5 m;(h)中等成岩相,压实、胶结和溶蚀程度中等,局部见粒间溶孔,牛深2井,3 694.9 m Fig.9 Types and characteritics of diagenetic facies of sandstone reservoirs in the upper third member of Shahejie Formation in Niuju-Changtan subsag of Eastern Sag |

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