A vessel (1) adapted to perform subsea wellbore related operations involving a riser string between the subsea wellbore and the vessel, e.g. drilling and/or wellbore intervention. The vessel (1) has a hull (2) and a riser storage (40) adapted to store therein of multiple risers in horizontal orientation. The riser storage (40) is adapted to store therein, or has stored therein, multiple pre-assembled riser stands (60), e.g. at least 25 riser stands, each riser stand being assembled from multiple riser sections (60, 61) connected end-to-end, e.g. each riser stand (62) consisting of two riser sections (60, 61), each riser section comprising a riser pipe and optionally one or more satellite pipes on the outside of and along the riser pipe, each riser section (60, 61) comprising a connector fitting arrangement at each end thereof, and each riser section (60, 61) comprising preferably one or more buoyancy members, wherein in a riser stand the connector fitting arrangement of one riser section is connected to a connector fitting arrangement of another riser section.

Offshore drilling system for performing subsea wellbore related activities including a drilling vessel, with a floating hull subjected to heave motion. A main cable heave compensation sheave is provided for heave compensation of a travelling block. A connection cable heave compensation sheave is provided between a connection cable winch and a top sheave assembly supported on the hull of the vessel in or above the moonpool. The main cable heave compensation cable sheave and the connection cable heave compensation sheave are mechanically interconnected so as to allow for synchronous motion thereof.

An offshore drilling rig includes a drill deck, at least one work center arranged in the drill deck; a diverter system operatively connectable at least to a riser extending towards the seafloor; a hoisting system adapted for raising or lowering tubular equipment through the work center; wherein the offshore drilling rig includes a first positioning system configured for positioning at least the work center and/or the diverter system and/or a riser tensioning system selectively at a first horizontal position and a second horizontal position, different from the first horizontal position; and wherein the hoisting system is operable to raise or lower tubular equipment through the work center when said work center is positioned at said first horizontal position.

Embodiments of an offshore drilling rig includinga drill floor deck having a hole defining a first well center;a first mast upwardly extending relative to the drill floor deck;a first hoisting system supported by the first mast and configured for hoisting and lowering tubular equipment through the first well center; wherein the load bearing structure of the first hoisting system is displaced from and located on a first side of the first well center;first pipe handling equipment for moving tubular equipment to the first hoisting system so as to allow the first hoisting system to hoist or lower the tubular equipment through the first well center; wherein the first pipe handling equipment is operable to move tubular equipment at least partly underneath the load bearing structure and/or through a gap formed in said load bearing structure.

A land based dynamic sea motion simulating test drilling rig has a soil bound foundation and a pivot structure secured to said foundation. A motion base is mounted on said pivot structure and pivotable about at least one horizontal pivot axis. A drilling tower is erected on said motion base and is provided with a hoisting device adapted to manipulate a drill string section in a vertical firing line. A drilling tubulars storage vertically stores drilling tubulars and a tubulars racker device moves drilling tubulars between the drilling tubulars storage device and the firing line allowing for assembly and disassembly of a drill string section in the firing line. A motion drive is provided which is adapted to impart cyclic pivoting motion about said at least one horizontal pivot axis to the assembly of the drilling tower, drilling tubulars storage, and tubulars racker device in order to simulate said assembly being subjected to a sea state induced motion.

The present invention relates to a method for riser string handling on an offshore drilling vessel (1), the offshore drilling vessel comprising a multiple firing line hoist system, a riser tensioner system (50) arranged in the second firing line, and a suspended riser transfer device (60). The method comprising the steps of lowering a riser string in the first firing line, and simultaneously assembling and preparing a riser tensioner system in the second firing line, wherein the riser hang-off assembly displaces the riser string, leaving the top end of the riser string exposed, from the first firing line to the second firing line to be connected to the riser tensioner system.

An offshore drilling vessel includes a main deck, a moonpool a firing line hoist system having a tower, a BOP transport system and a pivotally supported U-shaped working deck. The U-shaped working deck can be pivoted between an active position, in which it extends in a substantially horizontal direction such that it covers a portion of the moonpool, and a non-active position, in which it extends in a substantially vertical direction such that it provides room for a BOP to be moved by the BOP transport system from a storage position adjacent the moonpool into a launch position above the moonpool, in which launch position the BOP is located between the tower and the working deck.

A method for riser string handling on an offshore drilling vessel, the offshore drilling vessel including a multiple firing line hoist system, a riser tensioner system arranged in the second firing line, and a suspended riser transfer device. The method including the steps of lowering a riser string in the first firing line, and simultaneously assembling and preparing a riser tensioner system in the second firing line, wherein the riser hang-off assembly displaces the riser string, leaving the top end of the riser string exposed, from the first firing line to the second firing line to be connected to the riser tensioner system.

An offshore drilling rig comprising a drill deck, at least one work center arranged in the drill deck; a diverter system operatively connectable at least to a riser extending towards the seafloor; a hoisting system adapted for raising or lowering tubular equipment through the work center; wherein the offshore drilling rig comprises a first positioning system configured for positioning at least the work center and/or the diverter system and/or a riser tensioning system selectively at a first horizontal position and a second horizontal position, different from the first horizontal position; and wherein the hoisting system is operable to raise or lower tubular equipment through the work center when said work center is positioned at said first horizontal position.

The invention relates to underwater drilling for procuring and analyzing ground samples of a bed of a body of water. An underwater drilling device placed onto a bed of the body of water. By a drill drive a drill rod composed of at least one tubular drill rod element is drilled into the bed of the body of water in a first drilling step, wherein a drill core is received in a receiving part in the tubular drill rod element. The receiving part with the drill core is deposited in a storage place of a storage area on the base frame. Subsequently, one further drilling step is carried out with a further drill rod element. By means of sensor means at least one physical and/or chemical property of the drill core is determined. data on the storage place of the drill core in the second storage area.