Study On The Influence Of Sand Body Distribution Under The Control Of Sedimentary Facies And Diagenesis On Water Storage In Yingpanhao Zhiluo Formation

As one of the important factors threatening the safety of coal mine production,coal roof water damage has been highly valued by coal miners for many years.One of its focuses is to study the water-rich roof of coal seams.Experts and scholars have focused on the water-rich roof of coal seams,focusing on the information fusion and determining the weight of various geological data to predict the water-rich partition,but rarely combine sedimentary facies,diagenesis and water-rich.The sedimentary facies are formed in a specific environment,and the sand body formed retains the sedimentary characteristics at that time and has a certain control effect on the distribution of groundwater;diagenesis refers to the conversion of loose sediments under the influence of certain pressure and temperature.The physical and chemical processes of sedimentary rocks,as well as a series of physicochemical changes that occur later,diagenesis has a certain impact on sandstone pores and petrophysical properties.The water storage capacity of rock is an important factor in the evaluation of water richness.Therefore,through the analysis of sedimentary facies and diagenesis,it is important to study the effect of rock water storage capacity.Based on the systematic analysis and analysis of drilling,core,logging and logging data in the study area,the introduction of INPEFA logging and recognizing technology is guided by sequence stratigraphy,sedimentology,petrology and geophysics.The Zhiluo Formation of Yingpanhao Minefield re-division of the sequence stratigraphy,and on this basis,the sedimentary facies and sedimentary systems were identified;The diagenesis and pore characteristics of the Zhiluo Formation sandstone were studied by means of casting thin sections,scanning electron microscopy,overpressure porosity experiment and CT scanning three-dimensional imaging technique.Finally,the effects of sedimentary facies and diagenesis on the water storage of Zhiluo Formation were obtained by combining macroscopic and microscopic aspects.The specific understanding is as follows:(1)This paper selects the GR curve which can better reflect the change of shale quality and performs the INPEFA technology treatment.It follows the processing sequence from the whole to the local,combined with the lithology and logging data,and reclassifies the Zhiluo group into a long-term cycle,three The mid-term cycle,six short-term cycles and the establishment of the stratigraphic framework of the study area.The three medium-term cycles correspond to the first segment of the Zhiluo group,the second segment of the Zhiluo group,and the third segment of the Zhiluo group,each of which is subdivided into two sub-segments.(2)On the basis of sequence stratigraphic division,it is considered that the basin where the study area is located experienced a tectonic evolution that first declined and then rose,and formed sedimentary evolution of three sedimentary modes:braided river-braided river delta and meandering river.Further,sedimentary microfacies such as rivers,heart beaches,side beaches,natural dykes,floodplains,underwater distributary channels,subaqueous distributary channels,estuary dams,and flood plains are identified.(3)The diagenesis and pore characteristics of the Zhiluo Formation sandstone were analyzed by using casting thin sections,scanning electron microscopy,overpressure porosity experiment and CT scanning three-dimensional imaging technique.It is believed that the diagenesis of the research area is mainly composed of compaction,cementation and dissolution.Among them,the compaction and cementation are destructive diagenesis,which makes the pores of the rock smaller and the connectivity between the pores worse.The dissolution is a constructive diagenesis,which makes the pores of the rock become larger and the connectivity becomes better.(4)Comparing the experimental data with the previous research,it is considered that the water-bearing area of the braided river channel and the Xintan and the meandering river channelsedimentary area is good;the estuary dam,the underwater distributary channel deposition area,the medium water storage;the flood plain,the natural embankment The sedimentary areas such as the underwater distributary channel have poor water-bearing properties.