吐哈盆地胜北洼陷中——下侏罗统致密油烃源岩评价及油源对比  

Source Rock Evaluation and Oil⁃Source Correlation for Middle-Lower Jurassic Tight Oil in Shengbei Subsag,Turpan-Hami Basin

作　　者：刘锋 赵红静[2] 金颖 甘应星 曾雁 温旺彪 徐桂芳 LIU Feng;ZHAO Hongjing;JIN Ying;GAN Yingxing;ZENG Yan;WEN Wangbiao;XU Guifang(Research Institute of Exploration and Development,Tuha Oilfield Company,PetroChina,Hami,Xinjiang 839009,China;Hubei Key Laboratory of Oil and Gas Geochemistry and Environment,Yangze University,Wuhan,Hubei 430100,China)

机构地区：[1]中国石油吐哈油田分公司勘探开发研究院,新疆哈密839009 [2]长江大学油气地球化学与环境湖北省重点实验室,武汉430100

出　　处：《新疆石油地质》2023年第3期277-288,共12页Xinjiang Petroleum Geology

基　　金：国家自然科学基金(41302121,42072119)。

摘　　要：胜北洼陷风险探井沁探1井在西山窑组以下致密砂岩中见22层荧光级油气显示,需对所钻遇的烃源岩进行评价,确定致密油来源层系。西山窑组烃源岩在台参2井附近大部分层段为非—差烃源岩,但4 700.00~4 900.00 m层段为好烃源岩,在洼陷区的沁探1井则为中等—好烃源岩;三工河组为中等—好烃源岩。中—下侏罗统有机质整体为Ⅱ_2型—Ⅲ型,在西山窑组为成熟,在三工河组和八道湾组为高成熟。烃源岩可溶有机质中链烷烃碳数分布宽,C_(27)-C_(28)-C_(29)αααR构型甾烷呈反“L”型,表明以陆源高等植物输入为主的混合型有机质来源。西山窑组有机质中伽马蜡烷含量低,姥植比相对偏高,其沉积水体为相对低盐度的弱氧化—弱还原条件;三工河组和八道湾组有机质中低姥植比,富含伽马蜡烷,其沉积水体盐度较高,还原性较强。β-胡萝卜烷在三工河组全层段发育,且在部分层段颇为丰富,含量与主峰碳相当,表明这些层段具嗜盐细菌的贡献,为还原性水体沉积。据C_(27)/C_(29)αααR甾烷、姥植比、C_(19+20)/C_(23+24)三环萜烷、C_(24)四环萜烷/C_(26)三环萜烷、重排藿烷、β-胡萝卜烷相对含量等,可推断出三工河组原油来源于自身烃源岩;西山窑组底部原油经过二次运移,源自三工河组富含β-胡萝卜烷烃源岩层系,西山窑组中—上段油砂抽提物则与西山窑组烃源岩相关。22 oil and gas layers in the tight sandstones below the Xishanyao formation were interpreted in the risky exploration Well Qintan-1 in the Shengbei subsag,Turpan-Hami basin.It is necessary to evaluate the encountered source rocks and determine the tight oil source.The source rocks in the Xishanyao formation are non-or poor source rocks in most intervals near Well Taican-2,except the 4700-4900 m in-terval,and are moderate-good source rocks in Well Qintan-1 in the subsag.The source rocks in the Sangonghe formation are moderate to good.The organic matters in the Middle-Lower Jurassic are generally TypeⅡ2-Ⅲ.The Xishanyao formation source rocks are mature,while the Sangonghe formation and Badaowan formation source rocks are highly mature.The carbon number of the paraffins in the soluble organic matters in source rocks distributes in a wide range,and the C27-C28-C29αααR sterane shows a reverse“L”configuration,indicating a hybrid organic matters mainly sourced from terrestrial higher plants.The organic matter of Xishanyao formation has a low gammacerane content and a relatively high pristane-phytane ratio(Pr/Ph),corresponding to a weak oxidation-weak reduction sedimentary environment with relatively low salinity.The organic matter of Sangonghe formation and Badaowan formation have low Pr/Ph and high gammacerane content,showing a strong reduction sedimentary environment with high salinity.β-carotane is developed in the entire Sangonghe formation,and is quite abun-dant in some intervals,with the content equivalent to that of the main peak n-alkanes,indicating the contribution of halophilic bacteria and a reducing water environment in these intervals.According to the parameters such as C27/C29αααR sterane,Pr/Ph,C19+20/C23+24 tricyclic ter-pane,C24 tetracyclic terpane/C26 tricyclic terpane,rearranged hopane andβ-carotane,it can be inferred that the crude oil in the Sangonghe formation came from the source rocks of the same formation;the crude oil at the bottom of the Xishanyao formation originated from the S

关 键 词：吐哈盆地 胜北洼陷 中—下侏罗统 致密油 生物标志化合物 β-胡萝卜烷 烃源岩评价 油源对比 

分 类 号：TE122[石油与天然气工程—油气勘探]