Abstract
This paper presents the results of an investigation into fracture growth pattern in three horizontal wells, each fractured multiple times. The completion system was selected such that it allowed recording of the bottom-hole pressure in two critical locations; at the frac port which was being fractured, and, within the previously fractured part of the same wellbore. Downhole cups isolated the two locations from each other.
The data show remarkable results. All fractures initiated axially and re-oriented to become perpendicular to the minimum principal stress (MPS). The re-orientation details varied widely between different fractures in the same well, and also between wells. In-spite of these variations, there was no communication within the formation between the multiple fractures. All fractures in the same well had the same value of MPS, and in fact nearly the same in all three wells. In one of the wells there was obstruction to proppant movement inside the fracture which caused increasing pressures during fracture extension. In one instance this resulted in screen-out very near the wellbore early in the treatment, and in another case inside the fracture and close to the end of the stage. Still, the high pressures encountered during these fractures did not cause communication with the previous fractures. The growth pattern in all fractures can best be described as off-balance, with no evidence of "complexity".
