What Does Borehole Fracture Mean?
Borehole fractures are the result of a severe difference in the pressure of the drilling mud introduced into a bore and the hydrostatic pressure of the material through which the bore is drilled. Borehole fracture damage occurs in two ways:
- If the pressure of the drilling mud is higher than the hydrostatic pressure of the borehole wall, the mud will be forced into the surrounding material of the borehole wall. Drilling mud may stop circulating.
- If the hydrostatic pressure within the borehole's walls is higher than the pressure of the drilling mud, the same "kick occurrences" that precede blowouts in oilfield drilling will occur, although the damage in trenchless technology is more likely to resemble a collapse of the borehole wall.