A support structure for an offshore device is provided, including a vertical guide sleeve and three elongated guide sleeves positioned around the vertical guide sleeve, and various braces connecting the elongated sleeves and the vertical guide sleeve. The support structure also includes a transition joint including a cylindrical portion for connection to an offshore device, such as a support tower of a wind turbine assembly, and a conical portion connected to the vertical guide sleeve. To provide resistance to thrust, bending, and torsional fatigue, at least one set of braces is formed in an oval, racetrack, obround, or stadium configuration, and one or more horizontal stiffeners are positioned in the transition joint to maximize the strength of the support structure.

A method is for constructing a subsea well and an associated unit. The method may include: providing a unit having at least one component of a flow control assembly, the flow control assembly to be operable for controlling a flow of injection or production fluid during operation of the well after the well has been constructed; lowering the unit through sea toward a seabed; receiving part of the unit in a subsurface of the seabed to anchor the unit in place, part of the unit projecting above the seabed, whereby the component of the flow control assembly is positioned in the projecting part; and performing at least one well construction operation through a bore in the unit.

A wellhead foundation is for one or more subsea wells. The wellhead foundation has a suction foundation provided with a housing with an open bottom and a top which is closable with a top cover, and one or more pipes being attached to the housing and extending from the top of the housing and at least over a substantial part of the vertical extent of the housing towards or beyond the open bottom of the housing inside or outside of the periphery of the housing, and a straight upper portion of each pipe projecting up above the top of the housing and forming an upper well-pipe portion which forms part of a high-pressure barrier in the well. The straight upper pipe portion of each pipe is arranged parallel to the center axis of the housing. A method of establishing a subsea wellhead foundation is described as well.

A wellhead foundation is for one or more subsea wells. The wellhead foundation has a suction foundation provided with a housing with an open bottom and a top which is closable with a top cover, and one or more pipes being attached to the housing and extending from the top of the housing and at least over a substantial part of the vertical extent of the housing towards or beyond the open bottom of the housing inside or outside of the periphery of the housing, and a straight upper portion of each pipe projecting up above the top of the housing and forming an upper well-pipe portion which forms part of a high-pressure barrier in the well. The straight upper pipe portion of each pipe is arranged parallel to the center axis of the housing. A method of establishing a subsea wellhead foundation is described as well.

A wellhead foundation is for one or more subsea wells. The wellhead foundation has a suction foundation provided with a housing with an open bottom and a top which is closable with a top cover, and one or more pipes being attached to the housing and extending from the top of the housing and at least over a substantial part of the vertical extent of the housing towards or beyond the open bottom of the housing inside or outside of the periphery of the housing, and a straight upper portion of each pipe projecting up above the top of the housing and forming an upper well-pipe portion which forms part of a high-pressure barrier in the well. The straight upper pipe portion of each pipe is arranged parallel to the center axis of the housing. A method of establishing a subsea wellhead foundation is described as well.

A wellhead foundation is for one or more subsea wells. The wellhead foundation has a suction foundation provided with a housing with an open bottom and a top which is closable with a top cover, and one or more pipes being attached to the housing and extending from the top of the housing and at least over a substantial part of the vertical extent of the housing towards or beyond the open bottom of the housing inside or outside of the periphery of the housing, and a straight upper portion of each pipe projecting up above the top of the housing and forming an upper well-pipe portion which forms part of a high-pressure barrier in the well. The straight upper pipe portion of each pipe is arranged parallel to the center axis of the housing. A method of establishing a subsea wellhead foundation is described as well.

A wellhead foundation is for one or more subsea wells. The wellhead foundation has a suction foundation provided with a housing with an open bottom and a top which is closable with a top cover, and one or more pipes being attached to the housing and extending from the top of the housing and at least over a substantial part of the vertical extent of the housing towards or beyond the open bottom of the housing inside or outside of the periphery of the housing, and a straight upper portion of each pipe projecting up above the top of the housing and forming an upper well-pipe portion which forms part of a high-pressure barrier in the well. The straight upper pipe portion of each pipe is arranged parallel to the center axis of the housing. A method of establishing a subsea wellhead foundation is described as well.

A wellhead foundation is for one or more subsea wells. The wellhead foundation has a suction foundation provided with a housing with an open bottom and a top which is closable with a top cover, and one or more pipes being attached to the housing and extending from the top of the housing and at least over a substantial part of the vertical extent of the housing towards or beyond the open bottom of the housing inside or outside of the periphery of the housing, and a straight upper portion of each pipe projecting up above the top of the housing and forming an upper well-pipe portion which forms part of a high-pressure barrier in the well. The straight upper pipe portion of each pipe is arranged parallel to the center axis of the housing. A method of establishing a subsea wellhead foundation is described as well.

Extensible shells and related methods for constructing a support pier are disclosed. An extensible shell can define an interior for holding granular construction material and define a first opening at a first end for receiving the granular construction material into the interior and a second opening at a second end. The extensible shell can be flexible such that the shell expands when granular construction material is compacted in the interior of the shell. A method may include positioning the extensible shell in the ground and filling at least a portion of the interior of the shell with the granular construction material. The granular construction material may be compacted in the interior of the extensible shell to form a support pier.

Extensible shells and related methods for constructing a support pier are disclosed. An extensible shell can define an interior for holding granular construction material and define a first opening at a first end for receiving the granular construction material into the interior and a second opening at a second end. The extensible shell can be flexible such that the shell expands when granular construction material is compacted in the interior of the shell. A method may include positioning the extensible shell in the ground and filling at least a portion of the interior of the shell with the granular construction material. The granular construction material may be compacted in the interior of the extensible shell to form a support pier.