A reamer includes a housing, a flow tube extending along a longitudinal axis of the housing, and a plurality of reamer blocks arranged radially around the flow tube and configured to extend and retract relative to the housing. The reamer has a reamer ratio between 1.8 and 2.5. The reamer ratio is a ratio between an expanded diameter of the reamer when the plurality of reamer blocks is extended and a retracted diameter of the reamer when the plurality of reamer blocks is retracted.

A reamer includes a housing, a flow tube extending along a longitudinal axis of the housing, and a plurality of reamer blocks arranged radially around the flow tube and configured to extend and retract relative to the housing. The reamer has a reamer ratio between 1.8 and 2.5. The reamer ratio is a ratio between an expanded diameter of the reamer when the plurality of reamer blocks is extended and a retracted diameter of the reamer when the plurality of reamer blocks is retracted.

A ball valve is provided. The ball valve includes a housing, a ball seat arranged in the housing, a ball member mounted within the housing and being rotatable relative to the ball seat between open and closed positions, the ball seat and ball member defining respective through bores, the ball member including a sealing surface, a bore surface and a leading edge surface extending between the sealing surface and the bore surface, the leading edge surface being configured to cut a body extending at least partially through the valve upon closure of the ball member, wherein said leading edge surface is truncated. The ball member may include a relief region proximate the leading edge surface.

A technique facilitates failsafe closure of a valve used in, for example, a subsea test tree. The technique utilizes a valve combined with a cutter oriented to sever well equipment passing through an interior passage of the valve. The valve is operatively coupled with an actuation system having an actuator piston which controls cutting and valve closure. The failsafe valve and the cutter are shifted to an open position by applying pressure in a control fluid chamber to shift the actuator piston. However, the actuator piston, and thus the valve and cutter, are biased toward a closed position via pressure applied in a pressure chamber and a gas precharge chamber. The combined pressure ensures adequate force for shearing of the well equipment and closure of the valve when hydraulic control pressure is lost. In some applications, additional closing force may be selectively provided to the actuator piston.

A technique facilitates failsafe closure of a valve used in, for example, a subsea test tree. The technique utilizes a valve combined with a cutter oriented to sever well equipment passing through an interior passage of the valve. The valve is operatively coupled with an actuation system having an actuator piston which controls cutting and valve closure. The failsafe valve and the cutter are shifted to an open position by applying pressure in a control fluid chamber to shift the actuator piston. However, the actuator piston, and thus the valve and cutter, are biased toward a closed position via pressure applied in a pressure chamber and a gas precharge chamber. The combined pressure ensures adequate force for shearing of the well equipment and closure of the valve when hydraulic control pressure is lost. In some applications, additional closing force may be selectively provided to the actuator piston.

A ram block assembly enables a very high shearing, breaking, or parting force by utilizing guide rails and passageways within the ram block assembly to accept the rails and gird the rails against deviation from intended trajectory. The ram block rails and cavities enable application of extreme forces, opposing and concentrated within a small area, when actuating the ram block assemblies into the “open” or “close” positions. The ram block assemblies move in opposition, approaching each other and applying opposing forces against any material positioned between the ram block assemblies, and deforming, severing, breaking, shearing, parting, tearing and/or cutting, as the case may be, any said material positioned between the ram block assemblies. The severing of materials in the wellbore is known as “shearing,” and the apparatus performing this shearing operation as shear rams, shear ram blocks, shear blocks or shears.

There is provided systems, methods and apparatus for the use of directed energy, including high power laser energy, in conjunction with mechanical shearing, sealing and closing devices to provide reduced mechanical energy well control systems and techniques.

A well tool device (1) comprising a housing (10) having a through channel (11) with a first end (11a) and a second end (11b), said housing (10) further comprises a breakable ball seat (15), wherein a drop ball (17) received in the ball seat (15) partially or fully closes fluid communication in the through channel (11) of the housing (10). The breakable ball seat (15) is made of brittle and/or tempered glass, wherein the ball seat (15) is broken by a pressure build up in the housing (10) forcing the ball seat (15) against one or more disintegrating means (16), said disintegrating means (16) are provided as inside protrusions in the through channel (11).

A well tool device (1) comprising a housing (10) having a through channel (11) with a first end (11a) and a second end (11b), said housing (10) further comprises a breakable ball seat (15), wherein a drop ball (17) received in the ball seat (15) partially or fully closes fluid communication in the through channel (11) of the housing (10). The breakable ball seat (15) is made of brittle and/or tempered glass, wherein the ball seat (15) is broken by a pressure build up in the housing (10) forcing the ball seat (15) against one or more disintegrating means (16), said disintegrating means (16) are provided as inside protrusions in the through channel (11).

This invention relates to a method for recovering a tubular structure (3) from a well (1), wherein a so-called free point is defined as the location where the tubular structure is stuck in the well. The method comprising providing a downhole tool string comprising a pipe-severing tool and an upper part of the downhole tool string; lowering the downhole tool string into the tubular structure to release the free pipe. Before the step of triggering the pipe-severing tool to sever the tubular structure, the method includes releasing the pipe-severing tool and subsequent withdrawing the upper part, of the downhole tool string away from the free point towards the surface over at least a predefined distance. The invention relates to a downhole tool string for use in such method.