摘要：It is difficult to effectively identify low-resistance oil layers using conventional logging methods. The genesis of low-resistance oil reser-voirs is very complicated, so it is very necessary to adopt new methods to identify low-resistance oil layers. In this paper, a large amount of drilling, logging, and testing data of Jurassic reservoirs in the Ordos Basin are used to carry out a study on fine logging identification of low-resistance reser-voirs. The research results show that the lower limit of resistivity of the target oil layer and oil-water layer is basically around 6 Q·m, the rock density is less than 2.45 g/cm³， and the longitudinal wave time difference is greater than 224 us/m. The resis-tivity values of the oil layer and the oil-water layer in the study area are usually lower than the average value of the oil-bearing layer and the water layer, which account for 26.3%.The Jurassic strata have good petrophysical properties, low pressure, and long mud immersion time, which will lead to a large amount of mud invasion. This is an important reason for the decrease of the resistivity of the Ju-rassic oil layer and the increase of the resistivity of the water layer. The comparison shows that the resistivity of the Jurassic reservoir in the high salin-ity area is relatively low. There is a negative corre-lation between the apparent resistivity of the target sandstone reservoir and the salinity of the formation water, that is, the lower the salinity of the formation water, the higher the apparent resistivity. The high salinity areas in the study area are mainly concen-trated in the central and northeastern regions. The calculation results of formation water salinity in this paper can effectively identify low-resistance oil reservoirs. Therefore, in this paper, an effective new method for logging identification of low-resistance oil reservoirs is proposed.
关键词：Low-resistance oil reservoir;Well logging identification;Formation water salinity;Resistivity;Longitudinal wave time difference
