Method for inducing and further propagating formation fractures

摘要

Fractures are induced from lobe shaped inflatable members disposed at different axial locations along a string with frac ports in the circumferential gaps between the lobes. The lobes are inflated by landing a ball on a seat on a sleeve that is initially shifted enough to expose a fill port on each lobe. The lobes are inflated to a pressure that initiates fractures in the formation as the lobes extend. Further raising the pressure induces the sleeve to move a second time to open frac ports. The annulus can be cemented and fracturing can penetrate the cement to further propagate the initiated fractures from lobe inflation. The process is repeated at different levels until the zone of interest is completed. Sensors can relay information by telemetry techniques as to the onset of fractures or other well conditions. The sleeve for the frac ports can be moved in a variety of ways without intervention tools.

主权项

1. A fracturing method for a borehole in a subterranean location, comprising:
providing a string with circumferentially spaced extendable lobes oriented axially along said string and a plurality of selectively opened adjacent wall ports, said wall ports located between upper and lower ends of said adjacent lobes; configuring said lobe to leave at least one gap oriented axially along said string in an annular space surrounding said string when said lobes are extended; locating said string at a desired location for fracturing; extending said lobes into a borehole wall to apply force to the borehole wall to initiate fractures with an initial movement of a valve member that opens at least some said wall ports; mechanically stopping said valve member from further movement beyond said initial movement; selectively opening other said ports after said valve member initial movement by defeating said mechanically stopping to apply fluid pressure to the borehole wall to propagate the initiated fractures.