Daqing Branch of CNPC Logging Company Limited, Daqing 163412, Heilongjiang, China

In order to meet the needs of the development of thin beds and thin interbeds in oilfields, a high-resolution digital focusing dual laterolog equipment is developed using the interactive equipment emulation design method. This method is based on a combination of numerical simulation and circuit emulation. Through equipment emulation, a dual laterolog electrode system with a vertical resolution of 0.2 m is formed. The corresponding investigation depths for deep and shallow resistivities are of 1.09 and 0.38 m, respectively. The signal amplitude and the apparent resistivity measurement error under different formation conditions are also obtained. Field tests show that the vertical resolution and investigation depths of the designed dual laterolog tool are consistent with the theoretical results. The curve repeatability meets the quality requirements. The equipment emulation method effectively links theoretical design with equipment development. This method is not only useful for developing the dual laterolog tool with 0.2 m high resolution dual, but also suitable for the design of electrode-type logging tools.