塔里木盆地麦盖提斜坡罗斯2井奥陶系油气藏的TSR作用:来自分子标志物的证据

Effect of TSR on the crude oil in Ordovician reservoirs of Well Luosi-2 from Maigaiti Slope,Tarim Basin: Evidences from molecular markers

马安来 金之钧 朱翠山 顾忆 李慧莉 路清华

Ma Anlai Jin Zhijun Zhu Cuishan Gu Yi Li Huili Lu Qinghua

采用内标物色谱质谱方法，对罗斯2井原油中金刚烷系列、二苯并噻吩系列和硫代金刚烷系列进行了定量分析。罗斯2井原油中金刚烷系列化合物含量、4-甲基双金刚烷+3-甲基双金刚烷含量分别为10 818，331 μg/g，表明原油经历了较强的裂解作用，裂解比例达到90%左右。金刚烷指标表明原油成熟度在1.6%以上。罗斯2井原油可以检测到完整的硫代单金刚烷、硫代双金刚烷和硫代三金刚烷系列，硫代金刚烷、硫代单金刚烷、硫代双金刚烷和硫代三金刚烷含量分别为192，160，26和6 μg/g。高含量的硫代金刚烷表明罗斯2井原油的TSR强度大于绝大多数塔中地区下奥陶统鹰山组原油。TSR作用导致罗斯2井原油具有较高含量的二苯并噻吩，含量为8 201 μg/g，使得原油二苯并噻吩/菲比值（DBT/P）增加，导致C-/C-DBTs和C-/C-DBTs比值增加。

The study made a quantitative analysis of diamondoid, dibenzothiophenes and thiadiamondoid series in the crude oil from Well Luosi-2 via the GC-MS method with internal standards.The concentrations of diamondoid and 4-+3-methyldiamantane(4-+3-MD)are 10818 and 331 g/g in the study area,suggesting that the crude oil suffered serious cracking and the proportion of cracking oil is up to about 90%.The diamondoid indexes show that the maturity of crude oil from Well Luosi-2 is above 1.6% .Complete thiaadamantane,thiadiamantane,thiatriamantane series were detected from the Well Luosi-2 crude oil,with the contents of thiadiamondoid,thiaadamantane,thiadiamantane,thiatriamantane being 192,160,26 and 6 μg/g respectively.The high concentration of thiadiamondoid is a sign that the degree of thermochemical sulfate reduction(TSR)of oil from Well Luosi-2 is higher than that of most crude oil from the Lower Ordovician Yingshan Formation in Tazhong uplift.TSR results in the higher DBTs, about 8 201 μg/g,in the oil from Well Luosi-2, and in turn the higher ratios of DBT/P,C-/C-DBT and C-/C-DBT.

10.11743/ogg20180410