The most widely used Russian electrical and electromagnetic logging tools are the high-frequency electromagnetic sounding tools (VEMKZ/VIKIZ), the unfocused induction tool (IK), the unfocused lateral logging tool with gradient and potential arrays (BKZ), and the focused lateral logging tools with two three-electrode arrays (BK). A direct comparison of responses from these tools with responses from three benchmark Western tools-the Schlumberger HRLA high-resolution laterolog array tool, Schlumberger AIT array induction tool, and Schlumberger Rt Scanner triaxial array induction tool-was achieved using simulated tool responses from ID and 2D isotropic and anisotropic synthetic models of a conventional clastic reservoir typical of Western Siberia. A brief history of the Russian logging tools includes corresponding bibliography on tool theory, hardware, and processing options. We present the tool configuration for the most common versions of the Russian tools, describe some numerical algorithms used in this paper to calculate the tool responses in ID and 2D models, discuss and illustrate some workflows that provide quality control (QC) of Russian logs on the basis of radial ID modeling, address environmental corrections, and introduce standard interpretation of Russian logs. We also briefly mention the advanced processing tools, such as 2D inversion of BKZ data and joint 2D inversion of BKZ and VEMKZ logs. The comparison of tool responses in isotropic and anisotropic benchmark models includes comments from the point of view of Russian and Western log analysts. The comparison illustrates that in simple, mostly uninvaded models, focused responses of the HRLA and AIT tools have some advantages compared with the unfocused BKZ and VEMKZ measurements. However, simulated tool responses in realistic 2D isotropic and, especially, anisotropic models showed that the advanced 2D inversion-based processing is required for both Russian and Western tools to determine parameters of the virgin formation and invaded zone accurately.
|Number of pages||34|
|Publication status||Published - Feb 2020|