吉木萨尔凹陷芦草沟组致密油地质特征及有利区分布  

Tight Oil Geological Characteristics and Favorable Area Distribution of Lucaogou Formation in Jimusar Sag

作　　者：孙旭光[1] 哈斯叶提·叶斯博拉提 闫小龙 郑斌[1] 刘斌[1] 张军[1] SUN Xu-guang;HASIYETI Yesibolati;YAN Xiao-long;ZHENG Bin;LIU Bin;ZHANG Jun(Exploration and Development Research Institute of Petro China Xinjiang Oilfield Company, Kelamayi 834000, China)

机构地区：[1]中国石油新疆油田分公司勘探开发研究院,克拉玛依834000

出　　处：《科学技术与工程》2022年第13期5134-5145,共12页Science Technology and Engineering

基　　金：国家自然科学基金(42102328)。

摘　　要：芦草沟组是现阶段准噶尔盆地致密油勘探开发的主要层位,为分析其地质特征及有利区分布,从“源-储”配置条件出发,通过有机质类型、总有机碳(total organic carbon,TOC)含量、成熟度、储集岩类型及孔渗性分析,结合成藏埋藏下限进行有利区划分。研究表明:芦草沟组有机质干酪根类型以Ⅰ型及Ⅱ_(1)型为主,TOC含量介于0.16%~13.86%,平均含量在3.0%以上,灰质泥岩平均含量为3.79%。有机质成熟度介于0.55%~1.35%,主体分布在0.8%以上,由西向东,有机质成熟度逐渐降低,具有分布范围广、厚度大的特点,包括上、下两个“烃源甜点层”,“下甜点”厚度大于“上甜点”层。储层岩石类型多样,优质储层集中于过渡性岩类中发育,白云质粉砂岩是最主要的储层岩石类型,孔隙结构以微细孔喉发育为主,为典型的低孔特低渗储层,孔喉连通性好,储层孔渗相关性良好。结合致密油成藏深度下限,划分上芦草沟组一段及二段有利勘探区,其中芦草沟组二段Ⅰ类有利区集中分布在凹陷东南部J32-H-J25-J32-J22井区,芦草沟组一段Ⅰ类有利区分布在凹陷中南部J251-J32-J174井区。Lucaogou Formation is the main formation for tight oil exploration and development in Junggar Basin.In order to analyze the geological characteristics and distribution of favorable areas,the favorable areas were divided based on the analysis of organic matter type,total organic carbon(TOC)content,maturity,reservoir rock type and porosity and permeability,combined with the lower limit of reservoir formation and burial.The results show that the organic kerogen types of Lucaogou Formation are mainly typeⅠand type Ⅱ_(1),with TOC content ranging from 0.16%to 13.86%,average content above 3.0%,and average content of calcareous mudstone is 3.79%.The maturity of organic matter is between 0.55%and 1.35%,and the main body is more than 0.8%.From west to east,the maturity of organic matter decreases gradually,and it has the characteristics of wide distribution and large thickness,including the upper and lower two“source sweet spots”,and the thickness of“the lower sweet spot”is larger than“the upper sweet spot”.Reservoir rock types are diverse,high-quality reservoirs are concentrated in transitional rocks,dolomitic siltstone is the main reservoir rock type,and the pore structure is dominated by fine pore throats,which are typical low porosity and ultra-low permeability reservoirs.The pore-throat connectivity is good,and the reservoir porosity-permeability correlation is good.Combined with the lower limit of tight oil accumulation depth,the favorable exploration areas of the first and second member of the Upper Lucaogou Formation are divided.The favorable exploration areas of the second member of the Lucaogou Formation are mainly distributed in well J32-H-J25-J32-J22 in the southeast of the sag,and the favorable exploration areas of the first member of the Lucaogou Formation are mainly distributed in well J251-J32-J174 in the middle and south of the sag.

关 键 词：致密油 地质特征甜点 有利区 芦草沟组 吉木萨尔凹陷 

分 类 号：P624[天文地球—地质矿产勘探]