0 引言
1 地质背景
2 研究方法
2.1 白云石化时间模型
表1 t COD=0.3和t COD=1.0分别在不同温度条件下所需时间[30]Table 1 Time required for t COD=0.3 and t COD=1.0 under different temperature conditions respectively[30] |
样品 | T/℃ | 达到给定有序度预计时间/d | |
---|---|---|---|
t COD=0.3 | t COD=1.0 | ||
Agt | 25 | 1.6×103 | 2.5×109 |
Agt | 50 | 8.7×102 | 1.2×108 |
Agt-50-150 | 150 | 8.9×101 | 6.6×106 |
Agt-50-180 | 180 | 2.8×101 | 6.8×104 |
Agt-100-180 | 180 | 3.0×101 | 6.6×104 |
Ct-100-180 | 180 | 2.0×101 | 1.2×104 |
Agt-50-220 | 220 | 1.5×101 | 9.7×103 |
Agt-100-220 | 220 | 1.3×101 | 8.1×103 |
Ct-100-220 | 220 | 9.0×101 | 3.1×103 |
|
2.2 白云石晶胞体积计算
3 数据及结果
3.1 埋藏史
3.2 晶胞体积
表2 白云石晶胞体积计算结果(晶胞参数据文献[20, 29])Table 2 Calculation results of dolomite unit cell volume (unit cell parameter data according to Refs.[20, 29]) |
地层 | 岩性 | 有序度 | 晶胞参数/Å | 晶胞体积/Å3 | |
---|---|---|---|---|---|
a | c | ||||
塔里木盆地巴楚地区蓬莱坝组[20] | 细中晶白云岩 | 0.55 | 4.808 | 16.022 | 320.75 |
0.62 | 4.811 | 16.025 | 321.21 | ||
0.86 | 4.808 | 16.022 | 320.75 | ||
0.73 | 4.808 | 16.022 | 320.75 | ||
0.53 | 4.812 | 16.02 | 321.24 | ||
0.86 | 4.804 | 16.14 | 322.57 | ||
0.75 | 4.808 | 16.022 | 320.75 | ||
1 | 4.809 | 16.018 | 320.8 | ||
粗晶白云岩 | 0.89 | 4.808 | 16.022 | 320.75 | |
0.96 | 4.808 | 16.022 | 320.75 | ||
塔里木盆地巴楚地区蓬莱坝组[20] | 0.78 | 4.806 | 16.179 | 323.62 | |
0.83 | 4.808 | 16.022 | 320.75 | ||
0.85 | 4.808 | 16.022 | 320.75 | ||
0.98 | 4.808 | 16.022 | 320.75 | ||
1 | 4.808 | 16.022 | 320.75 | ||
粉晶白云岩 | 0.82 | 4.823 | 16.227 | 326.88 | |
0.71 | 4.811 | 16.047 | 321.65 | ||
0.71 | 4.815 | 16.119 | 323.63 | ||
加勒比海Cayman 岛中新统Cayman组[29] | 生物白云岩 | 0.68 | 4.809 2 | 16.008 | 320.63 |
0.4 | 4.837 9 | 16.195 | 328.26 | ||
0.6 | 4.828 | 16.077 2 | 324.54 | ||
0.45 | 4.836 | 16.2 | 328.1 | ||
0.52 | 4.823 | 16.111 | 324.54 | ||
0.58 | 4.806 | 16.001 | 320.06 | ||
南海中新统宣德组和四川盆地上震旦统灯影组[29] | 礁白云岩 | 0.389 | 4.827 8 | 16.176 | 326.5 |
0.392 | 4.823 2 | 16.131 | 324.97 | ||
泥晶白云岩 | 0.396 | 4.825 2 | 16.184 | 326.31 | |
0.333 | 4.827 3 | 16.183 | 326.58 | ||
生屑白云岩 | 0.408 | 4.827 2 | 16.153 | 325.96 | |
0.369 | 4.829 | 16.17 | 326.54 | ||
细晶白云岩 | 0.96 | 4.807 9 | 15.969 5 | 319.68 | |
0.97 | 4.806 8 | 16.015 4 | 320.46 | ||
晶粒白云岩 | 0.98 | 4.805 6 | 16.076 3 | 321.51 |
表3 方解石白云石化晶胞体积变化量(晶胞参数据文献[20, 29, 36])Table 3 Volume change of calcite dolomitized unit cell (unit cell parameter according to Refs.[20,29,36]) |
样品编号 | 晶胞参数(a)/Å | 晶胞参数(c)/Å | V dol/Å3 | V cal/Å3 | V cal-dol/Å3 | 体积缩小量/% |
---|---|---|---|---|---|---|
1 | 4.992 | 17.064 | 320.75 | 368.25 | 47.51 | 12.90 |
2 | 4.992 | 17.069 | 321.21 | 368.36 | 47.15 | 12.80 |
3 | 4.988 | 17.067 | 321.24 | 367.73 | 46.49 | 12.64 |
4 | 4.992 | 17.062 | 322.57 | 368.21 | 45.64 | 12.40 |
5 | 4.987 | 17.069 | 323.62 | 367.62 | 44.00 | 11.97 |
6 | 4.992 | 17.064 | 321.65 | 368.25 | 46.60 | 12.66 |
7 | 4.987 | 17.212 | 323.63 | 370.70 | 47.07 | 12.70 |
8 | 4.992 | 17.065 | 320.75 | 368.28 | 47.53 | 12.91 |
9 | 4.985 | 17.060 | 321.24 | 367.14 | 45.89 | 12.50 |
10 | 4.978 | 17.075 | 320.75 | 366.43 | 45.68 | 12.47 |
4 讨论
4.1 塔里木盆地寒武系准同生白云岩白云石化时间厘定
4.2 晶胞体积与有序度相关性
4.3 寒武系深层白云岩形成机制
图7 塔里木盆地阿瓦塔格组典型白云岩储层储集空间类型及特征(a)粉—细晶白云岩中的晶间孔,白云石较自形,可见黄铁矿,TS2井,埋深6 554.4 m;(b)粉—细晶白云岩中的晶间孔,白云石半自形,可见溶蚀扩容,S88井,埋深6 427.0 m;(c)微—粉晶白云岩中局部重结晶形成粉—细晶白云石斑块,斑块处发育晶间孔,TS2井,埋深6 550.5 m;(d)鞍状白云石沿裂缝分布,呈波状消光,S88井,埋深6 426.5 m;(e)深灰色粉晶—细晶白云岩,杂乱孤立不规则孔洞大量发育,TS1井,埋深7 874.17~7 873.78 m Fig. 7 Types and characteristics of typical dolomite reservoir space in Awatage Formation of Tarim Basin |