The Influence Of The Characteristics Of Shale Gas Reservoir To The Tectonic Evolution Of The North American Plate And The Tectonic Evolution Of The Prototype Basin

Based on the previous studies in ancient continental reconstruction of thirteen geological periods(Precambrian,Cambrian,Ordovician,Silurian,Devonian,Carboniferous,Permian,Triassic,Jurassic,Early Cretaceous and Upper Cretaceous,Eocene,Miocene),by using the theory of Plate Tectonic Analysis,Tectonics,Sedimentology,Basin Analysis as guidance,I study tectonic evolution in thirteen geological periods of North America Plate and Developmental features of prototype of basins during the main geologic periods.According to the distribution of shale strata in North America from previous summary,I focus my attention on the analysis of developmental features in shale strata of foreland basins and cratonic basins,in addition,I analysis the differences and similarities of gas-bearing properties among the different prototype of basins.Tectonic evolution and developmental characteristics of prototype of basins in North American plate has been summarized:(1)Late Proterozoic to early Paleozoic:In the breaking stage of Rodinia and Pannotia,there are mainly developed cratonic basins and passive continental margin basins;(2)From the beginning of Late Paleozoic--the converging stage of the supercontinent Pangea--mainly developed back-arc basins,foreland basins,cratonic basins and passive continental margin basins;(3)In the beginning of Early Mesozoic--the breaking stage of Pangea--mainly developed rift basins,passive continental margin basins in Eastern North America,and back-arc basins,foreland basins in Western North America;(4)After late Mesozoic,Eastern North America mainly developed passive continental margin basins,and back-arc basins,fore-arc basins and foreland basins in Western North America.According to previous studies,the shale gas basins in North America is mainly distributed in foreland basins and cratonic basins.The shale strata is mainly distributed in Devonian strata,Carboniferous strata,Jurassic strata and Cretaceous strata.This paper selects two shale strata--the Barnett shale in Fort Worth Basin in foreland basins and the Antrim shale in the Michigan Basin in cratonic basins--to analysis.Although the reservoir characteristics varies a lot in different basins,but their shale strata have some similarities.This paper will analyze from 5 different aspects:sedimentary environment,lithology,mineral composition,conditions gas accumulation and structure background.It is helpful to discuss same and different points of the gas-bearing property in shale strata in foreland basins and cratonic basins.