Abstract: A towing string useful for positioning a towed assembly into a horizontal well bore includes a towed assembly coupled to a tractor assembly. The tractor assembly is operable to convert introduced energy into a pulling force that is directed downhole. The tractor assembly includes a disposable motor and a coupled rotary tractor. The rotary tractor has a rotating portion that is operable to rotate around a central axis of the rotary tractor and a rotary element that is operable to frictionally engage the well bore wall. A method for using the towing string for positioning the towed assembly in the horizontal section includes introducing the towing string into the horizontal well bore, operating the towing string such that the rotary element frictionally engages the well bore wall, and introducing energy to the towing string such that the tractor assembly provides a pulling force directed downhole.

Abstract: The present invention relates to a completion assembly for running into a borehole in a formation through a well head or blowout preventer, comprising a casing string having a first end and a second end, and a drill pipe having a first end and a second end and extending through the well head or the blowout preventer and being releasably connected at the first end with the casing string. Furthermore, the invention relates to a completion method for completing a casing string. Moreover, the invention relates to a completion kit for making a completion assembly according to the present invention.

Abstract: An apparatus and method for improving control over the milling force applied to a milling bit that is turned through a rotary drive to form a hole in a wellbore casing. A bit-weighting sub is applied between the tubing used to lower the rotary drive's motor into the wellbore and the rotary drive itself, the sub serving to take the weight of the tubing off the rotary drive when the motor lands in operative connection with the drive, and further serving to apply a known milling force to the drive (and thus to the bit) independent of the weight of the tubing. In a preferred form the sub includes a spring that is compressed against the drive when the tubing and motor are landed.

Abstract: A retrievable frac mandrel and a well control adapter are used to efficiently accomplish well completion, re-completion or workover. The retrievable frac mandrel is inserted in a tubing head spool of a well to be completed, re-completed or re-worked. The well control adapter is mounted to a top of the tubing head spool and seals off against a top of the retrievable frac mandrel. After well completion, re-completion or workover is completed, the frac mandrel can be retrieved from the tubing head spool without killing or plugging the well.