摘要
准噶尔盆地中央坳陷西部三叠系超压强度大且成因复杂,但目前对三叠系超压分布与成因的研究相对较薄弱。基于钻井液相对密度、实测地层压力及测井数据等资料,利用测井曲线组合、Bowers法和声波速度−密度交会等方法,分析了中央坳陷西部三叠系超压测井响应特征,探讨了超压成因及主控因素。研究表明,三叠系超压段泥岩具有高声波时差、低电阻率的特征;中子密度及中子孔隙度均偏离正常压实趋势线,但在不同井区偏离幅度有所差异。现今三叠系超压主要为不均衡压实作用和深部压力传导共同作用形成。受三叠系岩性组合特征、沉积速率及断裂活动强度的影响,不同井区不均衡压实型超压贡献度存在明显差异,克拉玛依组尤为显著:沙窝地地区最大,莫西庄地区有所减小,征沙村地区最小。研究成果深化了对准噶尔盆地中央坳陷西部深层−超深层超压成因机制的认识。
[Objective]Overpressure in the Triassic interval of the western Central Depression,Junggar Basin,shows high magnitudes and complex genesis.Current understanding of its distribution and origin remains limited.[Methods]Integrating data of drilling fluid relative density,measured formation pressure,and logging data,and utilizing methods of logging curve combination,the Bowers method,and acoustic velocity-density crossplots,this study characterizes the log response characteristics of Triassic overpressure in the western Central Depression,and investigates the genesis and main controlling factors of Triassic overpressure.[Results]The mudstones of the Triassic overpressure section exhibit characteristics of elevated sonic time difference and reduced resistivity.The neutron density and neutron porosity of the mudstone deviate from the normal compaction trend line,but the degree of deviation spatially varies across different well areas.[Conclusion]The current Triassic overpressure is mainly caused by the combined effects of disequilibrium compaction and deep-seated pressure transfer.Affected by the lithological assemblage,sedimentary rate,and fault activity intensity,the relative contribution of disequilibrium compaction to overpressure generation varies significantly between well areas.Particularly in the Karamay Formation:the Shawodi area exhibits the largest contribution,followed by the Moxizhuang area,and the Zhengshacun area shows the smallest contribution.The research results provide a deeper understanding of the mechanism of deep to ultra-deep overpressure in the western central depression,Junggar Basin.
作者
徐龙龙
胡强
刘建章
肖雅文
叶尔阿曼·达吾力
XU Longlong;HU Qiang;LIU Jianzhang;XIAO Yawen;YEERAMAN Dawuli(Key Laboratory of Tectonics and Petroleum Resources,Ministry of Education,China University of Geosciences(Wuhan),Wuhan 430074,China;Hubei Provincial Key Laboratory of Oil and Gas Exploration and Development Theory and Technology,China University of Geosciences(Wuhan),Wuhan 430074,China;Faculty of Earth Resources,China University of Geosciences(Wuhan),Wuhan 430074,China)
出处
《地质科技通报》
北大核心
2025年第4期154-166,共13页
Bulletin of Geological Science and Technology
基金
国家自然科学基金项目(42372158,42072179)。
关键词
超压成因
超压测井响应
深层−超深层
三叠系
中央坳陷
准噶尔盆地
overpressure formation mechanism
overpressure logging response
deep to ultra-deep
Triassic
Central Depression
Junggar Basin
