A wellbore lining system that puts liners into place immediately behind the drill head tool is used in drilling and for preparing natural gas hydrate (NGH) deposits for production of its natural gas. The system overcomes the requirement of setting casing from the wellhead, which controls well bore diameter with depth and allows for flexibility in well bore size at any depth. Wellbore liners stabilize the well walls by being very tightly fitting against bounding rocks and sediments, which overcomes the requirement for cementing, which commonly accompanies conventional well casing. In addition, liners can be emplaced with designed impermeability, permeability, and complex flow-through patterns so that production processes, such as sand flow, can be put in place as part of a liner section.

A flow control system for a well includes a primary safety valve and a secondary safety valve for controlling flow from production tubing in the well. The primary safety valve includes a first valve body, a first flapper, a first control line port for receiving control fluid pressure from a control line, and a first actuator operable to open the first flapper in response to the control fluid pressure. The secondary safety valve is disposable within the valve body of the primary safety valve. The secondary safety valve also includes a second valve body, a second flapper, a second control line port for receiving control fluid pressure from the same control line as the primary safety valve when the secondary safety valve is disposed in the first valve body of the primary safety valve, and an actuator operable to open the second flapper in response to the control fluid pressure. A choke in fluid communication with the second control line port delays a closing of the second flapper relative to a closing of the first flapper in response to a decrease in the control fluid pressure.

A flow control system for a well includes a primary safety valve and a secondary safety valve disposable within a valve body of the primary safety valve. The secondary safety valve may include a control line port for receiving control fluid pressure from the same control line as the primary safety valve. A choke in fluid communication with the control line port delays a closing of the secondary safety valve relative to a closing of the primary safety valve in response to a decrease in the control fluid pressure.

A system involving a lower tubing mounted safety valve having one or two control lines further contains a landing nipple above for a wireline insert valve. One line that serves the lower safety valve is tied to a connection on the landing nipple for the insert valve. When the lower safety valve malfunctions the landing nipple wall is penetrated to get communication to the line coming from the lower safety valve so that such line can serve as a balance line for the insert valve. The other line from the surface to the other connection on the landing nipple serves as the operating line for the insert valve. Making one line serve a dual purpose eliminates one control line from the surface.

A rupture apparatus (50) often deployed within a wall of a casing string (53) of an oil and gas well, comprising a housing (51) defining a housing bore (54) with a bore inlet and a bore outlet; a carriage carrying a rupturable component (12) the carriage being moveable in the housing bore between a rupturable position, an open and a closed position. Thus the bore can be opened or closed or closed subject to rupture of the rupturable component (12). Moreover, after rupture the bore can still be closed. Wireless signals are normally used to for control, especially electromagnetic or acoustic signals. A pressure balancing port (6) may be defined in a wall of the housing allowing fluid communication between at least a portion of the housing bore, and an outside of the housing which can pressure-balance the carriage such that it remains stationary unless actuated.

The present invention relates to a downhole inflow production restriction device for mounting in an opening in a well tubular metal structure arranged in a wellbore, the downhole inflow production restriction device comprising a device opening, and a brine dissolvable element configured to prevent flow from within the well tubular metal structure through the device opening to an outside of the well tubular metal structure before being at least partly dissolved in brine, wherein the brine dissolvable element is at least partly made of a magnesium alloy. The present invention also relates to a downhole completion system and to a completion method.

The present invention relates to a downhole inflow production restriction device for mounting in an opening in a well tubular metal structure arranged in a wellbore, the downhole inflow production restriction device comprising a device opening, and a brine dissolvable element configured to prevent flow from within the well tubular metal structure through the device opening to an outside of the well tubular metal structure before being at least partly dissolved in brine, wherein the brine dissolvable element is at least partly made of a magnesium alloy. The present invention also relates to a downhole completion system and to a completion method.

Method and apparatus for creating a fluid communication line in a downhole environment between an annular chamber and a throughbore of a tool. The tubular wall therebetween is provided with circumferentially arranged recesses extending into the wall to provide selected thin-walled sections for perforation by a communication tool. The communication tool has two oppositely arranged punch heads, one aligned with a recess and the other between neighbouring recesses giving an orientationless configuration in operation. An embodiment for creating a fluid communication line through a tubing retrievable safety valve for operation of a wireline retrievable safety valve located therein is described.

The present invention relates to a downhole inflow production restriction device for mounting in an opening in a well tubular metal structure arranged in a wellbore, the downhole inflow production restriction device comprising a device opening, and a brine dissolvable element configured to prevent flow from within the well tubular metal structure through the device opening to an outside of the well tubular metal structure before being at least partly dissolved in brine, wherein the brine dissolvable element is at least partly made of a magnesium alloy. The present invention also relates to a downhole completion system and to a completion method.

The present invention relates to a downhole inflow production restriction device for mounting in an opening in a well tubular metal structure arranged in a wellbore, the downhole inflow production restriction device comprising a device opening, and a brine dissolvable element configured to prevent flow from within the well tubular metal structure through the device opening to an outside of the well tubular metal structure before being at least partly dissolved in brine, wherein the brine dissolvable element is at least partly made of a magnesium alloy. The present invention also relates to a downhole completion system and to a completion method.