沉积正演模拟在准噶尔盆地永进地区西山窑组辫状河三角洲砂体分布预测中的应用  

Distribution characteristic of favorable sand bodies in braided river delta of Xishanyao Formation,Yongjin area,Junggar Basin:Insight from stratigraphic forward modelling

作　　者：张增宝[1] 张立宽[2] 严一鸣 张立强[3] Zengbao ZHANG;Likuan ZHANG;Yiming YAN;Liqiang ZHANG(SINOPEC Shengli Oilfield Company,Dongying 257062,China;Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;School of Earth Science and Technology,China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]中国石化胜利油田分公司,山东东营257062 [2]中国科学院地质与地球物理研究所油气资源研究重点实验室,北京100029 [3]中国石油大学(华东)地球科学与技术学院,山东青岛266580

出　　处：《天然气地球科学》2024年第11期2064-2077,共14页Natural Gas Geoscience

基　　金：国家科技重大专项(编号:2017ZX05008-004);国家自然科学基金项目(编号:42030808)联合资助。

摘　　要：准噶尔盆地腹部永进地区深层侏罗系西山窑组勘探潜力大,但储层非均质性强、钻井少、地震资料品质差,利用地震资料预测有利储层难度大。采用沉积正演模拟方法,基于沉积背景和模型参数分析,构建了永进地区西山窑组辫状河三角洲相的四维沉积学模型,并预测了井间有利相带和砂体分布。研究结果表明:西山窑组发育4个湖泛面,可划分为4个四级层序;层序格架和孢粉含量垂向变化反映湖平面演化主要经历了7次湖退和6次湖侵;西山窑组沉积时期为弱氧化—弱还原环境,古水体深度较浅,平均古水深约为34.69 m;系统试错法模拟确认当河流水体沉积物浓度参数K为0.08 g/L时,6口井地层厚度吻合度均大于89%,且单井点岩性吻合度最高。沉积正演模拟揭示西山窑组沉积砂体叠加方式与规模在不同时期发生显著变化,早期发育垂向加积为主的大型河流沉积,河道复合砂体规模大,随后河流系统发育规模缩小,而沉积晚期以小型、快速横向迁移、分布范围广的河流为特征;辫状河三角洲平原分流河道是研究区优势储层相带,Y1井—Y3井和Y2井—Y6井等分流河道发育概率较高的地区可能是有利勘探目标。展示的案例研究表明,沉积正演模拟可为低勘探程度的深层储层预测提供有效工具。The deep-buried tight sandstone reservoirs of the Xishanyao Formation in Yongjin area,Junggar Basin have significant exploration potential.However,the reservoirs exhibit poor physical properties,strong heterogeneity,limited wells,and poor seismic data quality,making the prediction and characterization of favorable sand body distribution challenging.Based on sedimentary background analysis,this study employs sedimentary forward modelling and simulation parameter analysis to construct a four-dimensional sedimentology model of the braided river delta of the Xishanyao Formation in the study area,and also predicts favorable facies and the distribution of sand bodies between wells.The results indicate that there are four flood surface in the Xishanyao Formation,and the Xishanyao Formation can be divided into four fourth-order sequences.Based on the sequence framework and vertical changes of sporopollen content,the simulated evolution process of the lake level is set to seven regression and six transgressions.Results from the reconstruction of paleoenvironment and paleo-water depth based on trace element suggest that during the sedimentation period of the Xishanyao Formation,the environment was weakly oxidizing to weakly reducing,with relatively shallow water depth,averaging about 34.69 m.Using the systematic trial and error method,simulation results confirm that when the parameter K for sediment concentration in river water is set to 0.08 g/L,the conformity of layer thickness among six wells is higher than 89%,with the highest lithological conformity at individual well points.The simulated study indicates that large-scale river deposits dominated,primarily characterized by vertical aggradation,and the river channel complexes were relatively extensive in the early stage of Xishanyao Formation deposition.In the middle stage,the river system exhibited a smaller scale and limited developed characteristics.In the late stage,the features were characterized by small,rapidly laterally migrating rivers with a broad distribution

关 键 词：沉积正演模拟 有利砂体 辫状河三角洲 西山窑组 永进地区 

分 类 号：TE132[石油与天然气工程—油气勘探]