Abstract: A pressure barrier apparatus 2 for providing a removable pressure barrier in a borehole is described. The apparatus comprises a housing 6, 8 defining a central bore 10 having a first part 20 and a second part 22 separated by an erodeable pressure barrier member 18. The housing also defines a second fluid flow passage 12 for connecting the first part to the second part, and a plurality of conduits 24 for directing fluid onto the barrier member. A sleeve 30 has a first condition in which fluid communication between the first part 20 and the second fluid flow passage 12 is prevented, and a second condition in which fluid is permitted to flow from the first part to the second fluid flow passage to cause erosion of the barrier member.

Abstract: A method for repeatably providing large operating forces to actuate a remote device in a well which includes well production means penetrating to some depth, surface means for restricting or closing-off flow of product from the well and changing well pressure during an operating sequence of the well, at least one downhole pressure storage chamber, a valve communicating between the pressure storage chamber and prevailing well pressure, a piston/cylinder device coupled with the remote device to actuate the latter, and isolation valve for controlling the supply of pressure energy from the storage chamber to the piston/cylinder device. The method includes the steps of replenishably storing pressure in the storage chamber during the operating sequence, such stored pressure being derived from fluid flow permitted by the valve, and repeatably operating the isolation valve to apply differential pressure to the piston/cylinder device to actuate the remote device.

Abstract: A hydraulically operated setting tool for use in setting a plug or other component in a wellbore, and which is responsive to a supply of input actuating pressure to actuate the tool. An elongate tool housing has an inlet to receive the supply of actuating pressure, and an actuator element is axially displaceable relative to housing and also engageable with the plug or other component to set and release the component with respect to the wellbore. A pressure multiplier arrangement includes a hydraulically operated low pressure and high volume output piston which performs initial loading of the tool, and a high pressure, low volume output piston which provides a multiplied hydraulic force applied to the actuator element to set the plug or other component in a required position in the wellbore.

Abstract: A method for controlling entry from a main bore of a casing into a lateral bore of a producing well which incorporates (i) means for surface-actuated flow control in the lateral bore (ii) a flow control means located in the casing adjacent to the lateral bore, and said method comprising the steps of: a) removing the flow control means when entry to the lateral bore is required, said flow control means having an internal passage allowing upward flow of produced fluid from the main bore and through said passage; b) mounting a locating nipple on the casing adjacent to the lateral bore; c) engaging the flow control means with the nipple to locate the flow control means in the casing; and d) providing diverter means in the casing which engages with and is orientable relative to the nipple and operates to guide entry to the lateral bore from above the nipple following removal of said flow control means.

Abstract: A running tool which is intended to be lowered down a tubular member via a wireline extending from the surface to a connection to the upper end of the tool by which the tool is suspended, said tool being capable of advancing itself along the wall of the tubular member when required (e.g. when the tubular member is inclined to the vertical as a “lateral”), by repeated application and release of tension force in the wireline.