Well completions with expandable casing portions

摘要

Expandable casing portions are provided, such as casing slip joints or expansion joints, on opposite sides of a fracture initiation location to accommodate casing and formation movement during fracturing of a well. The fracture initiation location provided by forming openings through the well casing and then forming fan-shaped slots in the formation surrounding the casing. These fan-shaped slots circumscribe an angle about the axis of the casing substantially greater than the angle circumscribed by the opening itself through which the slot was formed. These techniques are particularly applicable to fracturing of horizontal wells, but are also useful on vertical wells. The expansion joints formed as tubular members having alternating inner and outer annular grooves. In another embodiment, the expansion joints formed by tubular members defining alternating inner and outer spiral grooves therein.