The article demonstrates the technology of testing reservoir layers represented by fractured clay-carbonate rocks in the Eastern Ciscaucasia. Practice shows that if the saturation of permeable rocks is uniform, the reliability of the tests can be ensured if the tested interval does not exceed 25 m. The probability of obtaining an inflow during tests significantly decreases with the increase in the amount of repression of the washing liquid and the duration of its impact on the reservoir. This is caused by clogging of the near-well zone of the reservoir, which results in the hydrodynamic connection of the reservoir with the well deteriorates. Test results are the most reliable if they are performed no later than 3-5 days after opening the reservoir, however, even in this case, the reservoir may be contaminated. For high-quality testing of reservoir layers represented by fractured clay-carbonate rocks, the following processes are required: to make an individual selection of the depression on the formation, to have a priori accurate information about the strength characteristics of the well walls.