超深层古油藏的定量表征及其...川中古隆起北斜坡灯影组为例_宋泽章.pdf

第 48 卷 第 2期2 0 2 3 年 2 月Vol.48 No.2Feb.2 0 2 3地球科学 Earth Sciencehttp:/https:/doi.org/10.3799/dqkx.2023.030超深层古油藏的定量表征及其对气藏形成的指示意义:以川中古隆起北斜坡灯影组为例宋泽章1，2，葛冰飞1，2，王文之3，田兴旺3，朱光有4*，杨岱林3，张宝收31.中国石油大学油气资源与探测国家重点实验室，北京 1022492.中国石油大学地球科学学院，北京 1022493.中国石油西南油气田分公司勘探开发研究院，四川成都 6100514.中国石油勘探开发研究院，北京 100083摘要：跨越多个构造期的深层、超深层油气成藏定量表征是地学界的一大难题.川中地区上震旦统灯影组天然气藏以典型的原油裂解气为主，油气演化经历了古油藏、古气藏直至现今气藏的复杂演化过程；古油藏的定量刻画是恢复其成藏过程的关键和核心.优选川中古隆起北斜坡上震旦统灯影组气藏为研究对象，以固体沥青为媒介，在岩心观察的基础上，综合“点”（固体沥青图像法定量表征）、“线”（固体沥青多矿物测井反演定量评价）、“面”（固体沥青含量平面分布定量表征）3个维度对固体沥青进行定量刻画，进而定量刻画古油藏并以体积法计算其资源量，以期从成藏角度对斜坡区的天然气勘探潜力评价提供支撑.研究结果表明：（1）灯影组储层固体沥青主要以半充填充填的状态赋存于孔隙空间中；灯二段固体沥青含量整体要高于灯四段；不论灯二段还是灯四段，上亚段固体沥青含量略高于下亚段；（2）固体沥青纵向和平面分布规律指示，纵向上，油气充注方向多为自上而下；平面上，油气充注主要存在两个方向：自德阳安岳裂陷槽向台内侧向充注；自北部斜坡区向南、向古隆起高部位侧向充注；（3）北斜坡地区灯影组储层古油藏完成裂解的时间早于大规模区域构造运动，因此可以用现今储层固体沥青的含量及分布来定量刻画古油藏.古油藏的识别标准为：固体沥青在孔隙空间充填度大于 25%且固体沥青含量大于 2%；（4）基于斜坡区丘滩体分布，定量刻画了川中古隆起北斜坡地区 5个可靠古油藏、4个潜在古油藏，借助体积法评价所得古油藏规模约 177.25108 t，完全裂解可产生原油裂解气约 109 893.94108 m3.关键词：固体沥青；原油裂解气；古油藏；超深层；川中古隆起；石油地质.中图分类号：P624.7 文章编号：1000-2383(2023)02-517-16 收稿日期：2023-01-22Quantitative Characterization of UltraDeep PaleoOil Reservoirs and Its Indication for Deep Gas Accumulation：A Case Study on the Dengying Formation,the North Slope of Central Sichuan PaleoUpliftSong Zezhang1，2，Ge Bingfei1，2，Wang Wenzhi3，Tian Xingwang3，Zhu Guangyou4*，Yang Dailin3，Zhang Baoshou31.State Key Laboratory of Petroleum Resources and Prospecting，China University of Petroleum，Beijing 102249，China基金项目：国家自然科学基金面上基金项目（No.42272161）；中石油科技创新基金（No.2021DQ020105）；超深层微生物白云岩储层孔隙结构多尺度定量表征（No.SCKLTJSZS20220044）.作者简介：宋泽章（1988-），男，副教授，主要从事致密储层评价及油气运聚成藏工作.ORCID：0000000155731490.Email：*通讯作者：朱光有,Email:引用格式：宋泽章，葛冰飞，王文之，田兴旺，朱光有，杨岱林，张宝收，2023.超深层古油藏的定量表征及其对气藏形成的指示意义：以川中古隆起北斜坡灯影组为例.地球科学，48（2）：517-532.Citation：Song Zezhang，Ge Bingfei，Wang Wenzhi，Tian Xingwang，Zhu Guangyou，Yang Dailin，Zhang Baoshou，2023.Quantitative Characterization of UltraDeep PaleoOil Reservoirs and Its Indication for Deep Gas Accumulation：A Case Study on the Dengying Formation，the North Slope of Central Sichuan PaleoUplift.Earth Science，48（2）：517-532.第 48 卷地球科学 http:/2.College of Geosciences，China University of Petroleum，Beijing 102249，China3.Exploration and Development Research Institute，Petro China Southwest Oil&Gas Field Company，Chengdu 610041，China4.PetroChina Research Institute of Petroleum Exploration&Development，Beijing 100083，ChinaAbstract:The quantitative characterization of deep and ultradeep hydrocarbon accumulation across multiple tectonic periods is one of the major sticking points in geoscience.The Dengying natural gas reservoirs of Upper Sinian in Central Sichuan are dominated by typical oilcracking gas,and the hydrocarbon evolution has experienced a complex process from paleooilreservoirs,paleogas reservoirs to todays gas reservoirs.The quantitative description of paleooilreservoirs is the key and core to restore its hydrocarbon accumulation process.In this paper,the Dengying gas reservoirs of Upper Sinian in the North Slope of the central Sichuan paleouplift is selected as the research object,the solid bitumen is taken as the medium,based on core description,the solid bitumen is quantitatively evaluated in three dimensions from point(quantitative evaluation of solid bitumen by image processing method),line(quantitative evaluation of solid bitumen by logging interpretation on multimineral inversion)to plane(quantitatively evaluate the plane distribution of solid bitumen),then quantitatively evaluated the paleooilreservoirs and their resources by volume method,to provide support for the evaluation of natural gas exploration potential in the slope area from the perspective of hydrocarbon accumulation mechanism.The results show that:(1)Solid bitumen in the Dengying Formation mainly exists in the pore space in the state of semifilling to fullfilling.Generally,the solid bitumen content of the second member of the Dengying Formation is higher than that of the fourth member.Also,the solid bitumen content in the upper submember is slightly higher than that in the lower sub member,no matter in the second member or the fourth;(2)The vertical and horizontal distribution of solid bitumen indicate that:in the vertical direction,the oil charging direction is mostly from top to bottom;while on the plane,there are two main directions for oil charging:from DeyangAnyue rift trough to the inner side of the platform;lateral charging from the northern slope area to south,to the high part of the paleouplift;(3)The paleooilreservoirs of Dengying Formation in the North Slope completed cracking earlier than the largescale regional tectonic movement.Therefore,the content and distribution of solid bitumen in the reservoirs can be used to quantitatively describe the paleooilreservoirs.The identification standard of paleooilreservoirs is:the filling degree of solid bitumen in pore space is greater than 25%and the of solid bitumen content is greater than 2%;(4)Based on the distribution of mound and beach body on the platformedge in the slop