Application Of Geostatistical Inversion In Coal Seam Prediction In Ningdong Mine Field

Coal exploration is important in China because of the identity of a large country in Coal Resources.Coal production in China is far ahead of the rest of the world.But we need to pay attention to know the stratigraphic structural characteristics in order to avoid the occurrence of safety problems such as gas leakage,roof fall,water inrush and so on.It's the most important to research the special geological structure,roof and floor lithology of coal seam,thickness distribution and water-rich zone.In this paper,according to the current technical means of seismic exploration,we research on fracture system,lithology change and coal seam thickness by the combining with seismic data,logging data,inversion of well and earthquake,multiattribute and ant body tracking tecnique.This research is based on the “Exploration of coal mine in yuanyang lake of Ningxia Ningdong field”.Through analyzing the climatic environment and sedimentary characteristics of strata in this area,we know the target layerlies in the Yanan formation of Middle Jurassic.The sedimentary environment is composed of impingement plain facies and delta front facies.Deposit stability and coal seam have thickness.Because of this type of geological structure,we can use inversion of post-satck to identify only thick coal seam.We can use the 3D lithologic data volume to describe the coal seam and lithology distribution characteristics of plates of them.Thanks of the seismic attribute analysis technique and the tracking attributes of the curvature body and the ant body,we can describe the fracture development of the target layer easily.Tn order to improve the sensitivity of HGG and HG and DLW to wave impedance,we use the way of random simulation and data weight construction,which acquire a new wave impedance data volume that can indicate lithologic change is fitted.This method can improve the vertical resolution of the inversion result.Combined with the actual geological sedimentary environment and well data,the wave impedance data volume is converted into lithologic data volume in time domain after adjusting the parameters and threshold values.By establishing the velocity model for time-depth conversion,the 3D lithologic data volume in the depth domain is obtained.Picturing the geological structure map of each coal seam and the lithologic thickness distribution map of the top and bottom plate,which provides a favorable basis for reservoir description.