摘要
泥页岩的成岩作用研究是成岩体系、孔隙结构以及地层超压成因分析的重要内容。综合运用X衍射、测井曲线、实测孔隙度等资料,定量分析了准噶尔盆地腹部地区黏土矿物转化量,结合温度、测井曲线、孔隙度等厘定了泥页岩成岩演化阶段,并探讨了超压发育机制。研究表明,准噶尔盆地腹部地区泥页岩的成岩演化主要可以分为3个阶段。在0~2 400 m,机械压实主导阶段,该阶段黏土矿物含量主要受沉积物源影响,含量及转化量变化不大,声波测井计算孔隙度略大于密度测井计算孔隙度,声波时差(AC)、密度(DEN)、补偿中子(CNL)曲线均减小,电阻率(RT)曲线增大。在2 400~4 200 m,化学压实与机械压实过渡阶段,伊蒙混层开始向伊利石、绿泥石转化,密度测井计算孔隙度与声波测井计算孔隙度相当,AC、DEN、CNL曲线减小幅度变缓,RT曲线小幅反转。在4 200 m以下,化学压实主导阶段,黏土矿物开始大量转化,长石开始大量溶蚀。随着深度增加,温度压力逐渐升高,温度达到120℃左右时,高岭石向伊利石转化,钾长石含量几乎降为0%,密度测井计算孔隙度小幅偏离正常演化趋势,声波测井计算孔隙度大幅偏离正常演化趋势,AC、DEN、CNL、RT曲线均发生反转。超压成因为复合成因,化学压实是研究区超压的主要成因之一。
The study of diagenesis of shale is an important part of the analysis of diagenesis system,pore structure and formation overpressure.Based on the data of X-ray diffraction,logging curve and measured porosity,the transformation amount of clay minerals in the hinterland of Junggar Basin was quantitatively analyzed.Combined with temperature,logging curve and porosity,the diagenetic evolution stage of shale was determined,and the mechanism of overpressure development was discussed.The study shows that the diagenetic evolution of shale in the hinterland of Junggar Basin can be divided into three stages.At the dominant stage of mechanical compaction from 0 m to 2400 m,the clay mineral content in this stage is mainly affected by sediment sources,and the content and conversion amount have little change.The porosity calculated by acoustic logging is slightly larger than that calculated by density logging.The sonic time difference(AC),density(DEN)and compensated neutron(CNL)curves all decrease,while the resistivity(RT)curves increase.From 2400 m to 4200 m,during the transition stage between chemical compaction and mechanical compaction,illite-montmorillonite mixed layer began to transform into illite and chlorite,and the porosity calculated by density logging is equivalent to that calculated by acoustic logging.The curve of AC,DEN and CNL decreases slowly,and the RT curve slightly reverses.Below 4200 m,in the dominant stage of chemical compaction,clay minerals begin to transform in large quantities,and feldspar begins to dissolve in large quantities.With the increase of depth,temperature and pressure gradually increase.When the temperature reaches about 120℃,kaolinite transforms into illite,and the content of potassium feldspar drops to almost 0%.The porosity calculated by density log-ging slightly deviates from the normal evolution trend,while the porosity calculated by sonic logging significantly deviates from the nor-mal evolution trend,and the AC,DEN,CNL and RT curves all invert.Chemical compaction is one of the main causes of overpressure in the study area.
作者
许晨航
李军
吴涛
吾尔妮萨罕·麦麦提敏
杜治伟
范佳怡
马鸿斌
XU Chen-hang;LI Jun;WU Tao;WUERNISAHAN·Maimaitimin;DU Zhi-wei;FAN Jia-yi;MA Hong-bin(School of Earth Sciences and Engineering,Xi'an Shiyou University,Xi'an 710065,China;Shanxi Key Lab of Petroleum Accumulation Geology,Xi'an Shiyou University,Xi'an 710065,China;Research Institute of Exploration and Development,Xinjiang Oilfield Company,PetroChina,Karamay 834000,China)
出处
《科学技术与工程》
北大核心
2025年第17期7080-7091,共12页
Science Technology and Engineering
基金
西安石油大学青年科研创新团队(2019QNKYCXTD06)。
关键词
泥页岩成岩作用
孔隙演化
测井响应
超压
准噶尔盆地腹部
mud shale diagenesis
pore evolution
logging response
overpressure
hinterland of Junggar Basin
