Research into the growth of bearing capacity of the near-wall zone during and after the borehole drilling operation

The purpose of this paper is to study the bearing capacity of the near-wall zone during and after borehole drilling to assess the actual condition of the borehole during the drilling process. The author makes a forecast of the quantitative growth of the open borehole bearing capacity based on the results of hydraulic testing performed in the real X1 East Cheleken borehole (Turkmenistan). Six hydraulic pressure tests of the open borehole were performed sequentially when the borehole reached the depths of 1950 m, 2236, 2677, 3409, 3760 and 4085 m upon running the 324-mm intermediate string to the depth of 1793 m during further deepening of the borehole. Over time, wall packing also occured at these levels, which was confirmed at the depth of 4085 m, when the bearing capacity of the borehole walls was restored. The bearing capacity of the near-wall area in the zone below the casing seat exceeded the calculated pressure of the theoretical hydrofrac by more than 60 kg/cm2. The increase in the borehole bearing capacity was 0.4509 kg/cm2 per day for the upper red-colored sediments. The author recognizes the fact that such studies were carried out only in one borehole and in one area, which allows us to refer to obtaining only an estimated quantitative result and only for a specific borehole condition. This work can be used as a methodology base for further studies. The author believes that it is possible to forecast the dynamics of increasing the bearing capacity of the near-wall zone of the boreholes drilled based on successive surveys, which can be used to assess the condition of the borehole during the drilling of subsequent boreholes in the area.