摘要
通过塔里木盆地塔中１０井油层和水层石炭系储集岩烃类宏观组成和分子地球化学特征研究，认识到油层和水层中储集岩含油率和烃类族组成存在着明显的差异。水洗作用对饱和烃生物标志化合物尤其是二环倍半庸影响较大，水层中倍半萜烷化合物已被消耗殆尽，三环萜烷含量降低，而伽玛蜡烷含量则相对增加；孕甾烷、升孕甾烷和重排甾烷的含量亦相对降低。水洗作用导致储集岩烃类芳烃组成中二苯井噻吩系列化合物的相对含量显著下降，二环和三环多环芳烃含量下降，而四环以上多环芳烃尤其是苯并萤蒽和苯并芘化合物相对含量显著增加。
Gross compositions, saturated and aromatic hydrocarbons distribution of Carboniferous sandstone reservoir rocks in oil zone and water zone for Tazhong-10 Well of Zhongyang Uplift in Tarim Basin were studied systematically using Rock-Eval, thin-chromatograph-flame ionization detection (TLC - FID), gas chromatograph, gas chromatograph-mass spectrometry techniques. The results suggest that reservoir hydrocarbon gross compositions between oil zone and water zone have significant differences. The relative contents of total hydrocarbons (saturated and aromatic hydrocarbons) in oil zone are abundant (higher than 70% ), but the resin and asphaltene contents are lower. In contrast, in water zone, the relative contents of total hydrocarbons are lower than 60%, but polar compound contents are higher. Water washing has noticeable effect on drimane series compounds, which have been depleted completely in water zone. However, homodrimane and drimane are predominant in oil zone, which show a similar distribution pattern with that of marine oil sands as well as asphaltic sands in other oil fields, Tarim Basin. Water washing dramatically decreases the contents of tricyclic diterpanes and pentacyclic triterpanes. In oil zone, the tricyclic diterpanes contents are higher than those in water zone, the C_(23) diterpanes/C_(30) hopane, C_(26+) diterpanes/hopanes and all diterpanes/hopanes ratios range from 0. 54 - 0. 99, 0. 20 - 0. 30, 0. 77 - 0. 19, in water zone the ratios are 0. 14, 0. 09, 0. 21, respectively. Pentacyclic triterpanes are also affected by water washing. In water zone, 18α(H) trisnorhopane (Ts) decreases and the ratio of Ts to Tin (17α(H) trisnorhopane) is 0. 53, which is lower than that (0. 94) in oil zone. The result is similar with works of Palmer (1984). In addition, the 17α(H), 21β (H) norhopane and C_(31)-C_(35) homohopanes contents decreases by water washing, the C_(29)-norhopane/ C_(30) hopane ratio of water zone and oil zone are 0. 48 and 0. 89, respectively. However, the water-zone reservoir hydrocarbon contains large amount of gammacerane, and the gammacerane index is greater for water-zone (28. 49% ) compared to the oil-zone (15. 25% ). This suggests that gammacerane is more resistant to water wishing than diterpanes and homohopanes. Steranes including pregnane, homopregrane, diasteranes and regular steranes are the major components for oil zone and water zone, but there are markedly differences for the relative contents of steranes between oil zone and water zone. The contents of pregnane, homopregrane, diasteranes decreases by water washing, (pregnane + homopregrane) /regular steranes and diasteranes/steranes ratios for oil zone are 0. 25, 0.71, the ratios of water zone are 0.07, 0.19, respectively. In addition, the C_(29) sterane S/ (S + R) and C_(29) sterane αββ/ (αββ + ααα) maturity ratios in water zone are lower than oil zone because of higher C_(27) αααR, C_(28)αααR and C_(29)αααR regular steranes in water zone. In addition, the content of dibenzothiophene series compounds in water zone decrease significantly by water washing, the relative abundance between benzonaphiothiophene and dibenzothiophene series of% total polycyclic aromatic hydrocarbons in oil zone and water zone decrease from 7. 60% to 2. 94% and 26.73% to 4.28%, respectively. However, the content of bicyclic and tricyclic aromatic hydrocarbon decrease slightly and the content of tetracyclic and pentacyclic aromatic hydrpcarbons, especially benzofluoranthene and benzopyrenes, increase markedly due to a decrease in light aromatic hydrocarbons as a result of water washing.
出处
《地球化学》
CAS
CSCD
北大核心
2000年第3期287-292,共6页
Geochimica
基金
中国石油天然气集团公司中青年创新基金
关键词
水洗作用
生物标志物
储集岩
油藏
烃类组成
water washing
biomarker
dibenzothiophene
reservoir rock
Tarim Basin
