摘要
轮南地区是塔里木盆地重要的油气产区之一,目前已发现了一批大中型油气田。该区含油气层位众多,奥陶系、石炭系和三叠系中均发现了天然气。地球化学特征研究表明,轮南地区天然气以甲烷为主,重烃气含量较低,轮南、塔河、解放渠东等油气田天然气主要为湿气,而轮古东地区、桑塔木地区以干气为主,吉拉克气田三叠系和石炭系天然气主体分别为湿气和干气;甲烷碳、氢同位素值分别为-46.7‰^-32.0‰和-190‰^-127‰,δ13 C2值主体介于-39.6‰^-31.6‰之间,烷烃气碳、氢同位素系列主体表现出正序特征,受同型不同源气混合的影响,部分样品发生了甲烷、乙烷同位素部分倒转。轮南地区天然气为油型气,其中轮南油田、塔河油气田和解放渠东油田天然气主体均为干酪根裂解气,混有部分原油裂解气;而轮古东气田、桑塔木气田天然气则主要为原油裂解气;吉拉克气田三叠系天然气主体为干酪根裂解气,混有部分原油裂解气,而石炭系天然气则为典型原油裂解气。轮南油田和塔河油气田天然气则来源于寒武系—下奥陶统和中上奥陶统烃源岩,而轮古东气田、桑塔木气田、解放渠东油田和吉拉克气田天然气主体来自寒武系—下奥陶统烃源岩。
Lunnan area is one of the important oil and gas producing units in the Tarim Basin,and a series of oil and gas fields have been discovered. The oil and gas in the-Lunnan area are reservoired in several strata, and natural gas has been found in Ordovician, Carboniferous and Triassic reservoirs. The study on geo- chemical characteristics of natural gas indicates that the gas in the Lunnan area is dominated by methane with a minor contribution of heavier hydrocarbons. The gases from Lunnan,Tahe and J iefangqudong fields are wet, whereas those from Lungudong and Sangtamu fields are dry, and gases from Triassic and Carbonif- erous reservoirs in Jilake Field are wet and dry, respectively. The carbon and hydrogen isotopic values of methane range from-46.7%0 to -32.0~0 and from-190%0 to -127~0, respectively, and the carbon isotopic values of ethane mainly range from -39.6g0 to -31.6%~. The alkane gases generally display positive carbon and hydrogen isotopic series,and several samples display partial reversal between methane and ethane due to the influence by mixing of gases from different source with the same organic type. Gases in Lunnan area are typically oil-associated, and those from Lunnan, Tahe and Jiefangqudong fields are mainly primary kero- gen cracking gas with some minor contribution of oil-cracking gas, whereas those from Lungudong and San- gtamu Fields are generally from secondary oil cracking. In-Jilake Field, the Triassic-reservoired gas is main2 ly kerogen-cracking assisted by oil-cracking gas, whereas the Carboniferous-reservoired gas is typically from oil cracking. The gases from Lunnan and Tahe Fields were derived from both Cambrian-Lower Ordo- vician and Middle-Upper Ordovician source rocks, and those from Lungudong, Sangtamu, Jiefangqudong and Jilake were mainly derived from Cambrian-Lower Ordovician source rocks.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2014年第1期53-61,共9页
Natural Gas Geoscience
基金
国家自然科学基金项目(编号:41302118)资助
关键词
轮南地区
天然气
地球化学特征
成因
来源
Lunnan area
Natural gas
Geochemical characteristics
Origin
Source
