The present invention relates to a downhole straddle assembly for straddling over a zone downhole in a well, the straddle assembly comprising a plurality of tubular sections mounted end to end in succession to form one tubular pipe having a first end tubular section forming a first open end of the tubular pipe, and a second end tubular section forming a second open end of the tubular pipe, said tubular pipe having an outer diameter, wherein the tubular section mounted to the first end tubular section is a first expandable metal sleeve being more pliant than the first end tubular section, and the tubular section mounted with the second end tubular section is a second expandable metal sleeve being more pliant than the second end tubular section. Furthermore, the present invention relates to a downhole straddle system for straddling over a zone downhole in a well and to a downhole straddle method.

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The present invention relates to a downhole straddle assembly for straddling over a zone downhole in a well, the straddle assembly comprising a plurality of tubular sections mounted end to end in succession to form one tubular pipe having a first end tubular section forming a first open end of the tubular pipe, and a second end tubular section forming a second open end of the tubular pipe, said tubular pipe having an outer diameter, wherein the tubular section mounted to the first end tubular section is a first expandable metal sleeve being more pliant than the first end tubular section, and the tubular section mounted with the second end tubular section is a second expandable metal sleeve being more pliant than the second end tubular section. Furthermore, the present invention relates to a downhole straddle system for straddling over a zone downhole in a well and to a downhole straddle method.

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A downhole seal element (10) comprises a cup portion (11) formed of or including a resiliently deformable material. The cup portion (11) extends between on the one hand a nose part (12) comprising an annulus intended for sealingly mounting the seal element on a mandrel (22) and on the other hand a skirt (13), the seal element flaring in shape between the nose part (12) and the skirt (13). The skirt includes extending therefrom away from the nose part (12) a plurality of elongate, flexible limbs (18) that are spaced at intervals about the skirt (13).

A downhole seal element (10) comprises a cup portion (11) formed of or including a resiliently deformable material. The cup portion (11) extends between on the one hand a nose part (12) comprising an annulus intended for sealingly mounting the seal element on a mandrel (22) and on the other hand a skirt (13), the seal element flaring in shape between the nose part (12) and the skirt (13). The skirt includes extending therefrom away from the nose part (12) a plurality of elongate, flexible limbs (18) that are spaced at intervals about the skirt (13).

A method of plugging a well extending into a formation to facilitate temporary or permanent abandonment of the well. The method comprises conveying a plug placement and verification tool (PPVT) through the well, to a plug formation location, the PPVT comprising a stinger for delivering a plugging material into the well, an expandable packer disposed at one end of the stinger and a pressure sensor disposed below the expandable packer, and operating the expandable packer to form a seal in the well above the pressure sensor. The method further comprises delivering a plugging material from the stinger into a region of the well above the expandable packer, thereby forming a plug in the well, and thereafter creating a pressure change above the plug and verifying the integrity of the plug using the pressure sensor.

A method of plugging a well extending into a formation to facilitate temporary or permanent abandonment of the well. The method comprises conveying a plug placement and verification tool (PPVT) through the well, to a plug formation location, the PPVT comprising a stinger for delivering a plugging material into the well, an expandable packer disposed at one end of the stinger and a pressure sensor disposed below the expandable packer, and operating the expandable packer to form a seal in the well above the pressure sensor. The method further comprises delivering a plugging material from the stinger into a region of the well above the expandable packer, thereby forming a plug in the well, and thereafter creating a pressure change above the plug and verifying the integrity of the plug using the pressure sensor.

A pressure control device for sealing a conduit is described. The pressure control device comprises a seal element comprising an elastomer, the seal element defining a seal element external surface portion, the seal element external surface portion defining an external perimeter. The external perimeter is adapted to increase as an environmental temperature increases, such that, in use, an increase in the environmental temperature can move the seal element external surface portion into engagement with the conduit or, once engaged with the conduit or if already engaged with the conduit, can create an improved seal with the conduit.

Some examples of the present disclosure relate to a method for washing an annulus that at least partially surrounds a casing in a well. The method comprises locating a tool inside a wellbore casing, and flowing a washing fluid from an injection aperture on the tool and into the annulus via a first casing aperture in the casing. An inflow region of the casing is created having a reduced pressure relative to the annulus, and the method involves flowing the washing fluid from the annulus and into the inflow region of the casing through a second casing aperture in the casing.

Some examples of the present disclosure relate to a method for washing an annulus that at least partially surrounds a casing in a well. The method comprises locating a tool inside a wellbore casing, and flowing a washing fluid from an injection aperture on the tool and into the annulus via a first casing aperture in the casing. An inflow region of the casing is created having a reduced pressure relative to the annulus, and the method involves flowing the washing fluid from the annulus and into the inflow region of the casing through a second casing aperture in the casing.

A tool for use in a wellbore comprising a seal assembly and a cone member configured to force the seal assembly radially outward into engagement with the wellbore. A shear thickening fluid is disposed within an area formed between the seal assembly and the cone member. The shear thickening fluid is configured to prevent relative movement between the cone member and the seal assembly when the shear thickening fluid is changed from a substantially fluid state to a substantially solid state due to a sudden force applied to the shear thickening fluid, by release of a sheared mechanism for example.