Interpretation of wireline log and core data from a mid-Jurassic sand/shale sequence

Abstract

AbstractInterpretation of downhole wireline logs is generally a major source of information used to build up a picture of the quality and distribution of reservoir rocks. Logging tools respond to a number of variables and comparison of a suite of different logs is usually required to isolate and identify the response due to a single factor, e.g. porosity or clay content. A new tool, the litho-density tool (LDT), has been used along with conventional logging tools in a mid-Jurassic sand/shale sequence. The LDT simultaneously measures Pe (effective photoelectric cross-section) and ρa (apparent bulk density). Pe is a function of atomic number which in turn reflects lithology or mineral composition. By using cross-plots derived from the LDT and other logs, patterns of mineral abundance are indicated.