A method for fracturing a hydrocarbon-containing formation includes running a tubing string into an open hole and uncased, non-vertical section of the wellbore, and expanding first, second, and third solid body packers until each sets and seals against the wellbore wall. The method also includes applying a first pressure within the tubing string inner bore such that the hydraulically actuated sliding sleeve moves from a closed port position to an open port position without engaging any fluid conveyed sealing device. The method also includes conveying a sealing device through the tubing string, passing through a first sliding sleeve and landing in and sealing against a second sliding sleeve's seat moving the second sliding sleeve to an open port position permitting fluid flow through a second port. And the method includes pumping fracturing fluid through the second port and into an annular wellbore segment to fracture the hydrocarbon-containing formation.