As a key factor restricting the fracturing effect of shale reservoir,the origin and content of quartz components have always been the focus of academic and industrial circles.Due to the great influence of diagenesis p...As a key factor restricting the fracturing effect of shale reservoir,the origin and content of quartz components have always been the focus of academic and industrial circles.Due to the great influence of diagenesis process,the accuracy of trace element determination to identify the origin of quartz is not good,which can not meet the increasingly accurate research requirements.In this paper,mineral quantitative analysis technology(QemScan)is used to identify quartz components by two-dimensional quantitative scanning,and the content data of quartz components with different grain sizes are extracted.The results show that the size of quartz particles is obviously controlled by the difference of sedimentary water and sedimentary environment,that is,quartz particles less than 30 mm are mainly concentrated in Long112 and Long114 layers,which is the normal oxygen environment under the background of medium retention in deep water environment;quartz particles larger than 20 mm are mainly concentrated in Long111 and Long113 layers,which is the poor oxygen environment under the background of strong retention in deep water environment.In shallow water environment,the stronger hydrodynamic conditions make the strata rich in terrigenous clastic quartz particles with larger grain size,and oxygen poor environment is conducive to the enrichment of authigenic quartz with smaller grain size.展开更多
Based on forward modeling of detachment fold, this study presents a method to analyze multi-level detachment structures and identify the authenticity of deep-seated anticlines using time-domain seismic section. The st...Based on forward modeling of detachment fold, this study presents a method to analyze multi-level detachment structures and identify the authenticity of deep-seated anticlines using time-domain seismic section. The steps include the conversion of the time-migrated seismic image into depth domain image using a constant velocity field, structural interpretation of the depth seismic image, measurement of each structural relief area and each height above reference level, plotting of area-height relationship chart with piecewise fitting etc. The area-depth correlation can help the division of structural sequences, the definition of detachment levels, the calculation of the tectonic shortening, and the identification of deep-seated structure. The segment area-height relationship is a feature of multi-level detachment structures, while little or no linear correlation between area and height is an indicator of non-deformation or pseudo-anticline. Regardless of the uncertainty of area-height relationship, the segment slopes will correspond to the differential shortenings of multi-level detachments, the intersection between adjacent segments will give the height of detachment surface above reference level and then help define the detachment level in original time-domain seismic section. This method can make use of time-domain seismic data to determine the geologic structure of complicated structure areas and assess risks of deep exploration targets. It has achieved good results in southern Junggar and eastern Sichuan areas.展开更多
基金This work was supported in part by National Natural Science Foundation of China(No.51804038)PetroChina Innovation Foundation(No.2018D-5007-0210)+1 种基金Innovation and entrepreneurship training program for college students in Hubei Province(S202010489032)Innovation and entrepreneurship project for college students of Yangtze University(2019026).
文摘As a key factor restricting the fracturing effect of shale reservoir,the origin and content of quartz components have always been the focus of academic and industrial circles.Due to the great influence of diagenesis process,the accuracy of trace element determination to identify the origin of quartz is not good,which can not meet the increasingly accurate research requirements.In this paper,mineral quantitative analysis technology(QemScan)is used to identify quartz components by two-dimensional quantitative scanning,and the content data of quartz components with different grain sizes are extracted.The results show that the size of quartz particles is obviously controlled by the difference of sedimentary water and sedimentary environment,that is,quartz particles less than 30 mm are mainly concentrated in Long112 and Long114 layers,which is the normal oxygen environment under the background of medium retention in deep water environment;quartz particles larger than 20 mm are mainly concentrated in Long111 and Long113 layers,which is the poor oxygen environment under the background of strong retention in deep water environment.In shallow water environment,the stronger hydrodynamic conditions make the strata rich in terrigenous clastic quartz particles with larger grain size,and oxygen poor environment is conducive to the enrichment of authigenic quartz with smaller grain size.
基金Supported by the China National Science and Technology Major Project(2016ZX 05003-001)
文摘Based on forward modeling of detachment fold, this study presents a method to analyze multi-level detachment structures and identify the authenticity of deep-seated anticlines using time-domain seismic section. The steps include the conversion of the time-migrated seismic image into depth domain image using a constant velocity field, structural interpretation of the depth seismic image, measurement of each structural relief area and each height above reference level, plotting of area-height relationship chart with piecewise fitting etc. The area-depth correlation can help the division of structural sequences, the definition of detachment levels, the calculation of the tectonic shortening, and the identification of deep-seated structure. The segment area-height relationship is a feature of multi-level detachment structures, while little or no linear correlation between area and height is an indicator of non-deformation or pseudo-anticline. Regardless of the uncertainty of area-height relationship, the segment slopes will correspond to the differential shortenings of multi-level detachments, the intersection between adjacent segments will give the height of detachment surface above reference level and then help define the detachment level in original time-domain seismic section. This method can make use of time-domain seismic data to determine the geologic structure of complicated structure areas and assess risks of deep exploration targets. It has achieved good results in southern Junggar and eastern Sichuan areas.
