A drainage device is for a tubular, telescopic pipe-landing unit having a through pipe bore partially formed of a center pipe extending from an upper end portion of an outer pipe-landing section and with a free end in through an upper end portion of an inner pipe-landing section, which is axially movable in the outer pipe-landing section. The center pipe has a fluid-communication opening arranged for pressure equalization between the pipe bore and an annulus between the center pipe and the outer pipe-landing section. The annulus has a drain passage arranged to be opened by the axial movement of the inner pipe-landing section into the outer pipe-landing section away from an extended, operative position, in which an abutment portion on the upper end portion of the inner pipe-landing section is resting sealingly against a seat portion on a lower end portion of the outer pipe-landing section.

A well construction method, and corresponding apparatus, in which a drilled bore (106) is lined with a plurality of successively smaller diameter sections of bore-lining tubing includes at least one casing (108, 110, 112) and at least one liner (120). The well construction method comprises: drilling a final section of a bore (106) to intersect a hydrocarbon-bearing formation (130); providing a shoe (134) at a distal end of a liner and a running tool (150) at a proximal end of the liner, and coupling an inner string (140) between the shoe (134) and the miming tool (150); running the liner (120) into the final section of the bore (106) such that the liner extends into the hydrocarbon-bearing formation (130); pumping a settable material (116) from surface (104), through the inner string (140), and through the shoe (134) to at least partially fill an outer annulus (114) surrounding the liner (120); and retrieving the inner string (140) and the running tool (150).

A method of forming a wellbore includes providing a drilling assembly comprising one or more lengths of casing and an axially retracting assembly having a first tubular; a second tubular at least partially disposed in the first tubular and axially fixed thereto; and a support member disposed in the second tubular and movable from a first axial position to a second axial position relative to the second tubular, wherein, in the first axial position, the support member maintains the second tubular axially fixed to the first tubular, and in the second axial position, allows the second tubular to move relative to the first tubular; and an earth removal member disposed below the axially retracting assembly. The method also includes rotating the earth removal member to form the wellbore; moving the support member to the second axial position; and reducing a length of the axially retracting assembly.

The present invention relates to methods and systems for establishing a well foundation as well as for drilling and installation of a surface casing without any use of a drilling rig.

A wellbore is plugged using a bismuth alloy. The wellbore is arranged so that a liquid bismuth alloy sets with an excess pressure of the plug relative to the borehole fluid pressure along a desired seal height distance.

An apparatus for flowing and mixing cement within a subterranean formation includes a housing, a flow control device, and baffles. The housing is configured to contain a cement additive. The housing includes a first end and a second end. The first end is configured to couple to a cement retainer. The flow control device is disposed at the second end of the housing. The baffles are disposed within the housing.

An apparatus for flowing and mixing cement within a subterranean formation includes a housing, a flow control device, and baffles. The housing is configured to contain a cement additive. The housing includes a first end and a second end. The first end is configured to couple to a cement retainer. The flow control device is disposed at the second end of the housing. The baffles are disposed within the housing.

A subsea coiled tubing drilling system and a subsea drilling device thereof are provided. The subsea drilling device includes an underwater derrick, a well head device and a dual-roller coiled tubing device, the dual-roller coiled tubing device includes an injection head, a roller for drilling and a roller for running casing, the injection head is arranged right above the well head device, the roller for drilling and the roller for running casing are distributed on two sides of the injection head; both the drilling coiled tubing and the casing running coiled tubing are capable of respectively penetrating through the injection head and the well head device in sequence. Drilling and casing running operations can be realized on the basis of not moving the underwater derrick or changing the self structure state of the underwater derrick, and operation steps can be simplified, and the work efficiency can be improved.

Systems and methods for cementing an annular space radially outward of a casing of a subterranean well include a float shoe located at a downhole end of the casing. A float valve is located within the float shoe and within a fluid flow path extending through the float shoe from an internal bore of the casing to an exterior surface of the float shoe. At least two wing members are located on an outer diameter surface of the casing, each of the wing members extending from the float shoe to an uphole end of the casing. The wing members are sized to define two or more separate sections of the annular space. A downhole splitter is located on a downhole surface of the float shoe. The downhole splitter is sized to seal between the downhole surface of the float shoe and an end surface of the subterranean well.

A wellbore is plugged using a bismuth alloy. The wellbore is arranged so that a liquid bismuth alloy sets with an excess pressure of the plug relative to the borehole fluid pressure along a desired seal height distance.