The Tectonic Conditions And Favorable Areas Of Coal Bed Methane Accumulation In Eastern Heilongjiang Province

The eastern Heilongjiang Province is the richest coal area in northeast China, with Hegang basin, Suibin depression, Jixi basin and Boli basin.Using the new seismic reflection profiles and drill-hole data from the eastern Heilongjiang Province, we reconstruct the structural evolution history of the basin based on structural analysis and explore the structure factors on the control effect of the coalbed methane. We apply the multi-level fuzzy comprehensive evaluation method based on the Arcgis software to predict favorable area of the coal bed methane. Some conclutions can been drawn as follows:1,The basin is superimposed by the Mesozoic residual basin and the Cenozoic basin, and the early cretaceous period influenced by the subduction of the ancient Pacific plate, the structure of the study area inland shell a strong stretch, form the downfaulted basin, control the formation of the Mesozoic coal accumulating basin.2,The Chengzihe and Muling Formations of the Lower Cretaceous are the main coal bearing strata. Tectonic conditions is stable enough to develop stable sedimentary formation. Fluvial-delta plain facies are the best sedimentary environment to coal bed.3,Late Jurassic period, the basin has been subjected to intense tectonic compression, formed the current residual basin characteristics of isolation. Syncline structures and reverse faults are considered to be beneficial to the enrichment pool-formed of CBM(coalbed methane).4,According to the integrated analysis on the coal ranks, coal beds thickness, sedimentary facies, gas content and structural conditions, the Xinyi-Nanshan coal mine and Xinan-Dalu coal mine of the Hegan Basin, the Southeast part of the Suibin Depression, the North geotectogene of Jixi Basin and the Southeast part of the Boli Basin are considered to be the most favorable area for coal bed methane exploration.