西昌盆地昭觉凹陷白果湾组泥页岩生烃动力学模拟及资源潜力  

Hydrocarbon generation kinetic simulation and resource potential of Baiguowan Formation shale in Zhaojue Sag of the Xichang Basin

作　　者：陈杨[1,2] 何伟 曾繁如[3] 龙潇 牟必鑫[1,2] 李轲 宋金辉 周瑞琦 CHEN Yang;HE Wei;ZENG Fanru;LONG Xiao;MU Bixin;LI Ke;SONG Jinhui;ZHOU Ruiqi(Sichuan Institute of Coal Field Geological Engineering Exploration and Designing,Chengdu,Sichuan 610072,China;Shale Gas Evaluation and Exploitation Key Laboratory of Sichuan Province,Chengdu,Sichuan 610091,China;College of Surveying and Geo-Informatics,Sichuan Water Conservancy College,Chengdu,Sichuan 611200,China)

机构地区：[1]四川省煤田地质工程勘察设计研究院 [2]页岩气评价与开采四川省重点实验室 [3]四川水利职业技术学院测绘地理信息系

出　　处：《天然气工业》2022年第3期50-60,共11页Natural Gas Industry

基　　金：四川省科技基金“西昌盆地构造特征及页岩气保存条件研究”项目(编号:2018JY0625);四川省自然资源厅“西昌盆地页岩气资源调查评价和区块优选”项目(编号:DK-2017-F-008);四川省煤田地质局科研项目“西昌盆地昭觉凹陷白果湾组陆相页岩生烃动力学及油气富集机理研究”(编号:KJ2020-02)。

摘　　要：昭觉凹陷上三叠统白果湾组是西昌盆地油气勘探的主要潜力层系之一,但目前尚处于勘探起步阶段,且未系统开展过生烃动力学研究,生烃能力、生烃规模及勘探潜力还不明确。为明确该区白果湾组泥页岩生烃动力学特征及油气勘探潜力,基于黄金管热模拟实验,取得了昭觉凹陷白果湾组泥页岩产烃率及动力学参数,建立了生烃模式,并估算了油气资源量。研究结果表明:(1)实验条件下,白果湾组泥页岩生成的天然气主要为C_(1),C_(2)~C_(5)次之。随着温度和EASY%R;的升高C_(1)和C_(2)~C_(5)的产率不断增大,而C_(2)~C_(5)、C_(6)~C_(14)和C_(14)的产率先增后减呈现典型的峰值分布,且不同的重烃气因其含碳原子个数不同导致产率不尽相同。(2)白果湾组泥页岩在0.5%≤R_(0)<1.24%时为生烃的成熟阶段,C_(1)、C_(1)~C_(5)的产率增长较快;在1.24%≤R_(0)<2.0%时为泥页岩生烃的高成熟阶段,C_(1)和C_(1)~C_(1)的产率增长最快,同时该阶段还生成较多的重烃气,C_(5)和C_(4)的产量极少,主要为C_(2)和C_(3);R_(0)>2.8%,C_(1)和C_(1)~C_(5)的产率增长速度仍然较快,依然保持增长趋势,重烃气的产率随之递减,为生烃的过成熟阶段,也是干气阶段,气态烃以C_(1)为主。(3)白果湾组泥页岩最大产油率为8.15 mg/g,最大产气率为22.68 mL/g;泥页岩生烃强度为54.8×10^(4)t/km^(2),有机碳-氢指数法估算泥页岩生烃量为8213.27×10^(4)t,具备形成中小型油气田的烃源岩条件。结论认为,该实验模拟恢复了白果湾组泥页岩的生烃演化过程,揭示了昭觉凹陷白果湾组泥页岩生烃潜力,为西昌盆地昭觉凹陷陆相油气勘探提供了依据。The Baiguowan Formation of Upper Triassic in Zhaojue Sag is one of the main potential strata for oil and gas exploration in the Xichang Basin.At present,however,it is in the initial exploration stage,its hydrocarbon generation kinetics has not been studied systematically and its hydrocarbon generation capacity,hydrocarbon generation scale and exploration potential have not been clarified.In order to clarify the hydrocarbon generation kinetic characteristics and oil and gas exploration potential of Baiguowan Formation shale in this area,this paper determines the hydrocarbon production rate and kinetic parameters of the Baiguowan Formation shale in Zhaojue Sag based on the gold tube thermal simulation experiment.In addition,its hydrocarbon generation model is established and the amount of its oil and gas resources is estimated.And the following research results are obtained.First,under the experimental conditions,the natural gas generated from the Baiguowan Formation shale is mainly C_(1)and secondarily C_(2)-C_(5).With the increase of temperature and EASY%R;,the yields of C_(1)and C_(1)-C_(5)increase continuously while the yields of C_(2)-C_(5),C_(6)-C_(14)and C_(14)increase firstly and then decrease,presenting a typical peak distribution.What’s more,the yields of heavy hydrocarbon gases are not the same for they are different in the number of carbon atoms.Second,when R_(0)is in the range of 0.5%-1.24%,the Baiguowan Formation shale is in the mature stage of hydrocarbon generation and the yields of C_(1)and C_(1)-C_(5)increase faster.When R_(0)is in the range of 1.24%-2.0%,the shale is in the high maturity stage of hydrocarbon generation and the yields of C_(1)and C_(1)-C_(5)increase the fastest,while more heavy hydrocarbon gases are also generated,which are dominated by C_(2)and C_(3)with little C_(5)and C_(14).When R_(0)is over 2.8%,the yields of C_(1)and C_(1)-C_(5)still increase at a higher speed,the yields of heavy hydrocarbon gases decline,and it is in the over-mature stage of hydrocarbon generation,i.e.,th

关 键 词：西昌盆地 昭觉凹陷 白果湾组 泥页岩 生烃动力学 生烃模式 

分 类 号：P618.13[天文地球—矿床学]