Well logging sedimentary facies of Silurian in Tazhong area of Tarim Basin

Key words:  Tarim Basin  Tazhong area  Silurian  well logging sedimentary facies  interpretation model

Abstract:

According to the sequence characteristics of well logging sedimentary fades obtained by common logging data,dip logging data and imaging logging data and the litho-facies interpretation by artificial neutral network (ANN)，the types, spatial distribution and paleocurrent direction of sedimentary facies in Tazhong area were researched. The results show that detritus tidal flat deposits include sub-tidal sand flat, inter-tidal channel, mixed sand-mud flat, supra-tidal mud flat. The comparison of litho-facies to logging data section shows almost no difference. The provenance is mainly located in the northwest of the study area, and secondary provenance is northeastern during the depositional period of lower sandstone paragraph. Based on litho-logies section interpreted by logging data, the sedimentary structure and paleocurrent interpreted by using dip legging with the core correction and treatment results by ANN,the logging data models and deposition models of the key wells of Silurian sedimentary micro facies in Tazhong area were established. These models not only provide sequential and relatively exact litho-facies section for the analysis of relations of vertical cycles overlay of key wells, but also contribute to the research of spatial distribution of sedimentary system in the study region. In addition, the conclusion is also helpful to sequence division and correlation of transitional continental-oceanic facies and to the search for subtle oil and gas reservoirs in Tarim area.