Characteristics and Origin of Crude Oils from Well Tazhong 82 Area of Tazhong Uplift
Received date: 2007-11-26
Revised date: 2008-10-09
Online published: 2008-12-10
This paper discussed the characteristics and origin of crude oils found in well Tazhong 82 area by systematic geochemical analysis. It shows that saturate fraction is the main component in the oils, while low carbon nalkanes are the main composition of the saturated hydrocarbon, the ratio of C21-/C 22+ranging from 1.4 to 5.4 and the biomarker content being very low. After n-alkanes being removed by molecule sieves, the biomarker content is still very low, the sterane contents of C27-C28-C29 have the distribution of “V” style, and the contents of rearranged steranes are high; the contents of tricyclic terpanes are higher and pentacyclic terpanes are very low in terpanes, C20 or C23 is predominant in tricyclic terpanes. Triaromatic sterances can not be clearly distinguished; dibenzothiophene present in a higher content, and δ13C ratio is light with a saturate δ13C ratio less than -32.8‰. These characteristics are different from Cambrian oils of well Tadong 2. MPI index shows that maturity of oils is about 0.8% (RO), which indicates that the oils of well Tazhong 82 area are not the products generated by organic matter at higher maturity, but were generatedy Ordovician organic matter with moderate maturity, and were flooded by Cambrian natural gas after accumulation, and accumulated again in the present reservoir.
Key words： Tarim basin; Tazhong 82 area; Crude oil origin.
GUO Jian-jun ;CHEN Jian-fa ;WANG Yi-feng ; SHI Sheng-bao ;MIAO Zhong-ying . Characteristics and Origin of Crude Oils from Well Tazhong 82 Area of Tazhong Uplift[J]. Natural Gas Geoscience, 2008 , 19(06) : 770 -774 . DOI: 10.11764/j.issn.1672-1926.2008.06.770
［1］邬光辉,李启明,张宝收,等.塔中Ⅰ号断裂坡折带构造特征及勘探领域［J］.石油学报,2005,26(1):27-37.
［2］韩剑发,梅廉夫,杨海军,等.塔里木盆地塔中地区奥陶系碳酸盐岩礁滩复合体油气来源与运聚成藏研究［J].天然气地球科学,2007,18(3):426-435.
［3］周新源,王招明,杨海军,等.塔中奥陶系大型凝析气田的勘探和发现［J］.海相油气地质,2006,11(1):45-51.
［4］梁狄刚,张水昌,张宝民,等.从塔里木盆地看中国海相生油问题［J］.地学前缘,2000,7(4):534-547.
［5］苗继军,贾承造,邹才能,等.塔中地区下奥陶统岩溶风化壳储层特征与勘探领域［J］.天然气地球科学,2007,18 (4): 497-500.
［6］张水昌,王招明,王飞宇,等.塔里木盆地塔东2油藏形成历史——原油稳定性与裂解作用实例研究［J］.石油勘探与开发,2004,31(6):25-30.
［7］肖中尧,黄光辉,卢玉红,等.塔里木盆地塔东2井原油成因分析［J］.沉积学报,2004,22(增):66-72.
［8］马安来,张水昌,张大江,等.塔里木盆地塔东2井稠油地球化学研究［J］.地质科技情报,2004,23(4):59-63.
［9］肖中尧,卢玉红,桑红,等.一个典型的寒武系油藏——塔里木盆地塔中62井油藏成因分析［J］.地球化学,2005,34(2):155-160.
［10］张水昌,梁狄刚,黎茂稳,等.分子化石与塔里木盆地油源对比［J］.科学通报,2002,47(增):16-23.
［11］张水昌.运移分馏作用——凝析油和蜡质油形成的一种重要机制［J］.科学通报,2000,45(6):667-670.
［12］Tompson K F M.Fractionated aromatic petroleums and the generations of gas-condensates［J］.Organic Geochemistry, 1987, 11(6): 573-590.
［13］Graas G W, Gilje A E, Isom T P,et al.The effects of phase fractionation on the composition of oils, condensates and gases［J］.Organic Geochemistry , 2000, 31: 1419-1439.
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