Control Of Geological Structure On Gas Of The Southern Margin Of Ordos Basin

This article based on the data which collected of geological exploration and gas materials from production and related topics of the southern margin of the Ordos basin,application the theory of plate tectonics and structural geology, structural geology gradual control of gas occurrence,theory of gas and geology,analyzing the development characteristics of geological structure and the occurrence and distribution features of gas,summarizes the basic law of gas geology,meanwhile,discussed on the different scales and different levels of evolution and development characteristics of geological structure effects the storage and distribution of gas, Revealed the geological structure on gradual control of gasIt is concluded that (1)Based on the research of tectonic framework and revolution in the study area,conclusions are drawn that since the formation of coal seam in Carboniferous-Permian,The study area has experienced at least three stages of tectonic stress field (Indosinian period,Yanshan period and Himalayan period),forming the complex geologic structure pattern nowadays;(2)Regional tectonic controlled the study area of gas distribution.In shallow seam area, paleo-uplift of Coal accumulation area,Anticline area and Extensional faults of Concentrated area,coal seam methane content and mine gas pour amount were lower;In deep seam area,Combine parts of Structure,Ancient sunken area of Coal accumulation and Syncline area,coal seam methane content and mine gas pour amount were higher;(3)Tectonic evolution of the study area on the occurrence of coal and gas can be divided into two phases:During the period of extrusion tectonic regime in the late Paleozoic-Mesozoic,were the formative stage of the coal and gas;during the period of extensional tectonic regime in Cenozoic,saving stage of coal and gas;(4)It was apparent that Progressively control feature of geological,Coal distribution and the main tectonic region structures in the study area controlled the development characteristics and distribution direction of Mines and mining geological structure,also controlled the extent of occurrence and distribution of coal-bed methane and gas;(5)Different constructed types controlled the different gas;Tectonic units in composite parts,Synclinal axis,Lower plate of reverse fault,Near the small faults always form high gas area;Anticline axis,Large normal fault intensive zone,the plate of reverse faul always form low gas area;...