Texture-genetic Classifications and Mapping Methods for Deltaic Deposits

Key words: 
• type of deltas /
• texture-genetic classification /
• litho-facies assemblages /
• layer correlation /
• multi-parameter nested mapping /

Abstract: Classifications for various depositional systems have been the general attention of sedimentary geologists. In recent years, sedimentologists have emphasized increasingly on the texture-genetic classification of deltaic depositional system which are the focus and hot issue for sedimentology study and hydrocarbon exploration and development. This paper aims to review the development of the study for deltaic depositional system, points out the  problems, demonstrates the specific meaning and scheme of texture-genetic classification for deltaic deposits systematically, and illustrates the advantages of this type of method. Simultaneously, a method of facies mapping which indicates the characteristics of texture-genetic classification for deltas is proposed with the related specific issues in this paper. Based on the principles of high resolution sequence stratigraphy and layer correlation droved by depositional facies, this mapping method emphasizes identifying depositional facies type by litho-facies assemblages and vertical successions. In order to reflect the grain size, distribution and sedimentary genesis of sand-body and represent the reservoir prediction adequately, multi-parameters from lithology, well logs and seismic are nested during mapping.