UNDERWATER DRILLING RIG AND SUPPORTING PLATFORM FOR IT Russian patent published in 1997 - IPC

FIELD: mining industry. SUBSTANCE: rig can be used for drilling oil and gas holes in shelves of Arctic seas in conditions of long-term ice covering and for this purpose drilling rig incorporates double-hull vessel with rigid connection of hollow hulls by means of upper and lower bulkheads, supporting platform, system for lowering and lifting tubes, system for feed and rotation of drill string. For servicing of rig in conditions of immersing, it is provided with mast which is secured between hulls of ship perpendicularly to longitudinal axis of hulls, tube store located on upper bulkhead with sluice chamber for reloading of tubes, manipulator, and inert-gas pumping station. Mast is made in the form of bell with skirt having two lateral partitions with coaxial holes, and one of them divides upper part into two chambers. Lower chamber communicates with hermetic compartments through hatches made in hulls. Made in lower bulkhead is opening for passing of drilling tubes which is coaxial with holes in lateral partitions, and lower of them is adapted for closing its hole. Gas pumping station is connected to upper chamber for personnel. Platform for drilling rig has base with unit for joining with rig body which is made in the form of suspended separable truss with guide members for connection with bottom part of body by means of adjustable grips which can be axially moved along guide members. Truss has at least one vertical shaft of variable cross section, and located in its lower part of smaller diameter is drill plate for suspension of casing strings. EFFECT: high efficiency. 12 cl, 5 dwg