Study on Seam Features and Control Factors of Huagang Formation of Xihu Depression in East Sea

In order to study development features of the seams in Huagang Formation of Xihu Depression, the paper discussed the major control factors of the sea ms development. The statistic analysis method of the well logging and recording data in the study zone, the sedimentology graphic and map analysis and other method were applied to study the formation environment and development features of the seams. The results showed that the distribution of the seams in Huagang Formation W as wide and the thickness variation was high. Along the expansion direction of the basin, the seams were symmetrical distributed, the distributions of the seams were n onuniform and the features of the north and south zones were obvious. During the sedimentary period of the Huangang Formation, Xihu Depression was in the depressi on period and the development of the fluvial facies- delta facies- lacustrine facies sedimentary environment would be favorable to the coal formation. The seam distribut ion features were affected by the basic floor features and the sedimentary environment control and the paper pointed out that the sedimentary environment was the mai n factors of the seam development.