0 引言
1 地质概况和基础地球化学特征
表1 柴达木盆地西部和北缘天然气组分(%)和稳定碳同位素(‰,VPDB)组成Table 1 Components (%) and stable carbon isotopes (‰, VPDB) of natural gas in the western part and northern margin of the Qaidam Basin |
油气田 | 井号 | 地层 | C1 /% | C2 /% | N2 /% | 干燥 系数 | δ13C1 /‰ | δ13C2 /‰ | R O /% | 油气田 | 井号 | 地 层 | C1 /% | C2 /% | N2 /% | 干燥 系数 | δ13C1 /‰ | δ13C2 /‰ | R O /% |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
狮子沟 | S205 | E3 2 | 79.5 | 6.4 | 3.0 | 0.84 | -40.6 | -29.8 | 0.8 | 扎哈泉 | ZT3 | E3 1 | 73.8 | 11.1 | 4.0 | 0.84 | -36.8 | -21.8 | 0.8 |
S58 | E3 2 | 78.8 | 6.0 | 2.7 | 0.85 | -40.0 | -27.7 | 0.9 | 昆北 | Q12-H5 | E3 1 | 58.7 | 17.4 | 8.7 | 0.66 | -30.6 | -25.9 | 1.3 | |
花土沟 | HN5-43 | N1 | 67.5 | 6.0 | 16.9 | 0.87 | -54.6 | -35.9 | 0.6 | 南翼山 | N105 | N2 1 | 86.9 | 5.6 | 3.3 | 0.91 | -33.0 | -23.8 | 1.1 |
游园沟 | YP3 | N2 1 | 72.9 | 11.0 | 5.4 | 0.84 | -40.6 | -27.9 | 0.8 | N14 | E3 2 | 90.3 | 2.1 | 1.2 | 0.98 | -32.1 | -20.5 | 1.2 | |
尕斯 | Y8-371 | E3 2 | 80.1 | 5.8 | 6.6 | 0.91 | -42.1 | -28.4 | 0.8 | N2-5 | E3 2 | 90.6 | 5.6 | 1.4 | 0.92 | -34.3 | -25.9 | 1.0 | |
跃进 | YⅡ5-13 | E3 1 | 91.0 | 1.8 | 1.7 | 0.97 | -47.7 | -28.2 | 0.7 | 尖北 | JT2 | 基岩 | 81.8 | 2.3 | 14.6 | 0.97 | -23.1 | -21.6 | 2.2 |
英东 1号 | Y1-2-B1 | N2 2 | 73.3 | 9.9 | 4.3 | 0.85 | -37.9 | -27.2 | 0.9 | 东坪 | DP171 | 基岩 | 92.4 | 2.5 | 3.4 | 0.97 | -31.0 | -20.8 | 1.3 |
Y1-2-B4 | N2 2 | 87.9 | 4.3 | 2.9 | 0.94 | -36.6 | -26.8 | 0.9 | DP1 | 基岩 | 88.5 | 2.0 | 7.6 | 0.97 | -25.0 | -20.8 | 1.9 | ||
Y27-1 | N2 2 | 86.3 | 5.0 | 3.2 | 0.93 | -37.7 | -26.7 | 0.9 | P1-2-7 | 基岩 | 88.2 | 2.0 | 7.6 | 0.97 | -25.3 | -21.4 | 1.9 | ||
Y38-3 | N2 2 | 88.0 | 5.0 | 2.1 | 0.93 | -39.5 | -27.6 | 0.9 | P1-2-8 | 基岩 | 88.1 | 2.0 | 7.5 | 0.97 | -24.9 | -21.0 | 2.0 | ||
Y29-1 | N2 1 | 81.7 | 6.3 | 4.1 | 0.91 | -40.5 | -30.9 | 0.9 | 牛东 | N105 | J | 78.0 | 6.8 | 7.0 | 0.90 | -35.5 | -25.0 | 0.9 | |
Y4-2 | N2 1 | 79.5 | 6.7 | 4.1 | 0.90 | -39.6 | -27.8 | 0.9 | N1 | J | 88.8 | 3.9 | 4.1 | 0.95 | -34.7 | -23.5 | 1.0 | ||
Y9-4 | N2 1 | 81.6 | 3.6 | 7.2 | 0.94 | -40.0 | -28.7 | 0.9 | N1-2-1 | J | 76.7 | 8.2 | 6.1 | 0.88 | -37.8 | -25.3 | 0.8 | ||
英东 3号 | YD301 | N2 1 | 80.4 | 6.1 | 3.9 | 0.90 | -39.5 | -27.0 | 0.9 | 昆特依北 | K2 | 基岩 | 90.7 | 4.1 | 3.5 | 0.95 | -30.0 | -22.1 | 1.4 |
YD3-3 | N2 1 | 80.0 | 6.6 | 4.4 | 0.90 | -40.5 | -26.8 | 0.9 | 冷湖3 | LHZ14 | J | 74.9 | 9.0 | 5.4 | 0.87 | -46.8 | -30.5 | 0.7 | |
乌南 | L4-5 | N2 1 | 80.8 | 7.1 | 3.6 | 0.90 | -39.5 | -27.0 | 0.9 | 冷湖4 | LQ4 | N1 | 56.3 | 13.1 | 13.5 | 0.78 | -38.7 | -27.5 | 0.7 |
W8-11 | N2 1 | 87.3 | 6.2 | 2.2 | 0.90 | -28.6 | -24.3 | 1.5 | 平台 | P302 | E1+2 | 82.4 | 4.2 | 11.2 | 0.93 | -31.3 | -24.8 | 1.2 | |
WB6-19 | N2 1 | 86.3 | 6.3 | 1.4 | 0.91 | -42.1 | -26.1 | 0.8 | 南八仙 | X1-1 | N2 1 | 89.6 | 3.7 | 4.5 | 0.94 | -24.2 | -21.3 | 2.1 | |
扎哈泉 | Z11-33 | N2 1 | 88.1 | 5.2 | 2.5 | 0.90 | -34.8 | -26.1 | 1.0 | X17 | E3 1 | 91.2 | 2.9 | 4.7 | 0.96 | -22.7 | -20.2 | 2.3 | |
Z11-4 | N2 1 | 86.6 | 6.2 | 2.5 | 0.89 | -33.5 | -25.1 | 1.1 | X18 | E3 1 | 89.7 | 3.5 | 5.5 | 0.95 | -29.0 | -23.4 | 1.5 | ||
Z11-8-5 | N2 1 | 95.7 | 0.2 | 2.8 | 0.99 | -39.1 | -26.0 | 0.9 | 马北 | MB2-9 | 基岩 | 91.3 | 2.4 | 7.6 | 0.97 | -25.3 | -19.7 | 1.9 | |
Z218 | N2 1 | 68.0 | 14.2 | 3.6 | 0.73 | -42.8 | -29.4 | 0.8 | MB1-1 | 基岩 | 75.8 | 7.5 | 7.8 | 0.84 | -30.5 | -24.7 | 1.3 | ||
Z7-1-5 | N1 | 74.0 | 9.5 | 6.2 | 0.86 | -42.0 | -26.8 | 0.8 | MB2-1 | 基岩 | 78.6 | 7.3 | 8.2 | 0.87 | -27.8 | -24.7 | 1.6 | ||
Z7-2-3 | N1 | 80.9 | 9.6 | 3.5 | 0.85 | -41.0 | -27.2 | 0.8 | MX106 | E3 1 | 87.8 | 3.1 | 8.0 | 0.96 | -28.0 | -22.4 | 1.6 | ||
Z9-2-1 | N2 1 | 82.1 | 6.3 | 4.3 | 0.91 | -39.2 | -25.3 | 0.9 | MX1-3 | E3 1 | 89.2 | 2.9 | 7.3 | 0.96 | -26.1 | -21.7 | 1.8 | ||
ZP1 | N2 1 | 71.5 | 12.4 | 5.7 | 0.77 | -39.4 | -26.5 | 0.9 |
2 样品和分析方法
2.1 样品
2.2 轻烃组分和单体烃碳同位素分析
3 结果与讨论
3.1 天然气成因类型
图5 柴达木盆地西部和北缘天然气中C5 - 7轻烃的典型气相色谱(a)柴西S205井;(b)柴北缘K2井注:2,2-DMC4=2,2-二甲基丁烷;2-MC5=2-甲基戊烷;2,2-DMC5=2,2-二甲基戊烷;MCC5=甲基环戊烷;2-MC6=2-甲基己烷;CC6=环己烷;1,1-DMCC5=1,1-二甲基环戊烷;1,c3-DMCC5=1,c3-二甲基环戊烷; 1,t3-DMCC5=1,t3-二甲基环戊烷; MCC6=甲基环己烷 Fig.5 Representative gas chromatograms of C5 - 7 light hydrocarbons of natural gas in the western part and northern margin of the Qaidam Basin |
表2 柴达木盆地西部和北缘C5—C7轻烃组分(%)和单体碳同位素(‰,VPDB)组成Table 2 Components (%) and individual carbon isotopes (‰, VPDB) of C5-C7 light hydrocarbons in the western part and northern margin of the Qaidam Basin |
井号 | ΣDMCC5 /% | n-C7 /% | MCC6 /% | 3RP/% | 5RP/% | 6RP/% | K1 | δ13CMCC5 /‰ | δ13CMCC6 /‰ | 井号 | ΣDMCC5 /% | n-C7 /% | MCC6 /% | 3RP/% | 5RP/% | 6RP/% | K1 | δ13CMCC5 /‰ | δ13CMCC6 /‰ | ||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
S205 | 18.0 | 51.5 | 30.5 | 37.8 | 16.2 | 45.9 | 1.07 | -21.7 | -21.9 | ZT3 | 5.7 | 84.6 | 9.6 | 67.0 | 4.7 | 28.2 | 1.05 | -18.1 | -21.4 | ||
S58 | 20.2 | 44.0 | 35.7 | 35.2 | 14.8 | 50.0 | 1.07 | -20.5 | -23.1 | Q12-H5 | 47.8 | 33.5 | 18.8 | 58.5 | 28.9 | 12.6 | 1.45 | ||||
HN5-43 | 30.4 | 44.1 | 25.5 | 60.9 | 19.7 | 19.4 | 1.18 | N105 | 19.4 | 34.6 | 46.0 | 29.1 | 13.5 | 57.4 | 1.24 | -18.2 | -21.6 | ||||
YP3 | 13.9 | 63.0 | 23.1 | 48.4 | 14.6 | 37.0 | 1.32 | -22.7 | -23.7 | N14 | 13.3 | 49.4 | 37.4 | 21.0 | 7.7 | 71.4 | 1.28 | ||||
Y8-371 | 15.9 | 59.5 | 24.7 | 47.7 | 15.3 | 37.0 | 1.13 | -20.7 | -21.9 | N2-5 | 19.5 | 50.4 | 30.1 | 47.7 | 15.6 | 36.7 | 1.29 | ||||
YⅡ5-13 | 40.3 | 31.7 | 28.0 | 56.6 | 20.8 | 22.5 | 1.20 | JT2 | 15.5 | 21.6 | 62.8 | 18.6 | 10.9 | 70.5 | 1.06 | -23.5 | |||||
Y1-2-B1 | 19.3 | 51.7 | 29.1 | 40.9 | 14.5 | 44.6 | 1.43 | DP171 | 14.5 | 51.2 | 34.2 | 36.7 | 11.6 | 51.7 | 1.17 | -23.2 | -25.1 | ||||
Y1-2-B4 | 17.8 | 59.7 | 22.5 | 43.1 | 15.7 | 41.2 | 1.33 | DP1 | 9.0 | 58.7 | 32.3 | 40.2 | 6.9 | 52.9 | 1.13 | ||||||
Y27-1 | 15.7 | 62.2 | 22.2 | 48.5 | 13.4 | 38.1 | 1.53 | P1-2-7 | 7.6 | 65.3 | 27.1 | 41.8 | 6.4 | 51.9 | 1.11 | ||||||
Y38-3 | 20.5 | 57.4 | 22.1 | 42.1 | 16.2 | 41.7 | 1.42 | P1-2-8 | 13.3 | 55.6 | 31.0 | 43.0 | 11.7 | 45.3 | 1.17 | ||||||
Y29-1 | 20.7 | 54.1 | 25.1 | 43.8 | 14.6 | 41.5 | 1.27 | N105 | 10.5 | 54.8 | 34.7 | 36.2 | 8.6 | 55.2 | 1.13 | ||||||
Y4-2 | 16.9 | 58.0 | 25.0 | 45.5 | 14.6 | 39.9 | 1.27 | -19.6 | -20.5 | N1 | 17.9 | 26.4 | 55.8 | 23.1 | 12.3 | 64.6 | 1.16 | -21.9 | -24.2 | ||
Y9-4 | 21.0 | 57.5 | 21.5 | 51.8 | 15.6 | 32.6 | 1.47 | N1-2-1 | 18.0 | 27.9 | 54.1 | 31.5 | 13.0 | 55.5 | 1.26 | ||||||
YD301 | 20.5 | 54.2 | 25.3 | 41.3 | 15.8 | 42.9 | 1.44 | K2 | 16.3 | 27.3 | 56.4 | 25.6 | 11.8 | 62.6 | 1.21 | -24.6 | |||||
YD3-3 | 20.7 | 54.6 | 24.7 | 43.6 | 16.1 | 40.3 | 1.27 | -19.5 | -21.0 | LHZ14 | 15.8 | 47.2 | 37.0 | 39.4 | 13.0 | 47.5 | 1.16 | -24.8 | -25.6 | ||
L4-5 | 16.3 | 54.7 | 28.9 | 17.8 | 7.1 | 75.2 | 1.42 | LQ4 | 17.4 | 32.7 | 50.0 | 28.6 | 13.4 | 58.1 | 1.18 | ||||||
W8-11 | 10.1 | 55.3 | 34.5 | 31.9 | 7.9 | 60.2 | 1.13 | -22.1 | P302 | 12.2 | 45.4 | 42.4 | 40.1 | 12.6 | 47.3 | 1.22 | |||||
WB6-19 | 18.0 | 47.4 | 34.6 | 37.7 | 14.8 | 47.5 | 1.16 | -18.8 | -22.1 | X1-1 | 12.9 | 37.5 | 49.7 | 33.2 | 12.8 | 54.1 | 1.10 | ||||
Z11-33 | 20.1 | 57.8 | 22.2 | 51.4 | 17.8 | 30.8 | 1.38 | -20.2 | -22.4 | X17 | 8.1 | 66.7 | 25.2 | 35.4 | 11.5 | 53.1 | 1.12 | ||||
Z11-4 | 20.6 | 56.7 | 22.6 | 52.3 | 17.9 | 29.8 | 1.37 | X18 | 13.2 | 37.8 | 49.0 | 37.1 | 11.7 | 51.3 | 1.11 | -22.9 | -22.4 | ||||
Z11-8-5 | 19.7 | 53.9 | 26.4 | 38.4 | 15.7 | 45.8 | 1.25 | MB2-9 | 18.3 | 38.5 | 43.3 | 33.3 | 9.0 | 57.6 | 1.18 | ||||||
Z218 | 46.9 | 38.8 | 14.3 | 60.0 | 24.6 | 15.4 | 1.17 | MB1-1 | 14.9 | 44.9 | 40.2 | 20.4 | 8.6 | 71.0 | 1.18 | ||||||
Z7-1-5 | 14.7 | 59.3 | 26.0 | 42.7 | 14.6 | 42.7 | 1.20 | MB2-1 | 14.3 | 50.0 | 35.7 | 27.4 | 9.9 | 62.7 | 1.17 | ||||||
Z7-2-3 | 15.1 | 59.0 | 25.8 | 45.8 | 12.9 | 41.3 | 1.29 | MX106 | 11.5 | 52.8 | 35.7 | 47.7 | 6.9 | 45.5 | 1.09 | -27.1 | -24.9 | ||||
Z9-2-1 | 19.6 | 52.2 | 28.2 | 39.3 | 16.0 | 44.6 | 1.30 | MX1-3 | 13.4 | 35.8 | 50.8 | 25.8 | 9.6 | 64.6 | 1.13 | ||||||
ZP1 | 22.6 | 51.0 | 26.5 | 46.4 | 17.8 | 35.8 | 1.17 | -20.9 | -22.5 |