Logging measurements in a well make it possible to measure the properties of rocks and fluids and can represent thousands of meters of data. Logging data enable quality assessment of drilled layers and archiving of data, and the data are stored in the form of diagrams and drawings. Different probes have different vertical resolutions and depth range. They do not always react the same way to the same rocks. The resolution of the layer, however, is related to the depth range and the geometry of the measurements. Cementing, which is performed after the installation of protective pipes, is very important in the construction of the well. There are two cement joints in the well. One contact occurs between the cement and the pipe, and the other between the cement and the formation. The function of cement is to insulate the well from the surrounding rock and thus prevent the uncontrolled intrusion of liquids and gases upwards through the interspace between the outer wall of the protective pipe and the wall of the well. Good cementing prevents the loss and contamination of the drilling muds, strengthens the columns of protective pipes so that they cannot move, protects the pipes from corrosion and provides support to the pipe or prevents the collapse of the unconsolidated wall of the well. Cement, however, can be lost, e.g., also in cracks, and a poorly cemented well occurs. To perform logging with a CBL probe, we had to find a suitable well. The well had to be cemented and filled with water. The well in which we performed logging is located in Laško, in the area of the Laško health resort.
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