Abstract: Apparatus and a method for adding and removing tubulars whilst containing the pressure within a drill string and/or maintaining circulation of drilling fluid down a drill string using a diverter sub which is able to open up to mud flow from a side mud port and close off the flow of mud from above the drill string with or without continuous rotation of the drill string.

Abstract: An underwater drilling rig (1) in modular form, which can be simply assembled underwater and in which standard tubulars and tubular assemblies are stored in a novel arrangement within containers (6) and can be added to, and removed from, the string in the well bore, whilst there is continuous circulation of drilling fluid and also continuous segregation of drilling fluid from the seawater.

Abstract: Slips (1, 21, 41) for engaging any jointed, coiled or flexible tubular with substantially no scoring, gouging or scraping, such as when supporting a drill string in a borehole or gripping a tubular (2, 22) during the connection or disconnection of a tool joint or pulling a cable or pipeline; additionally, applying a pre-determined minimum gripping force in order to avoid rotary slippage when the weight of the string is insufficient to achieve a conventional slips action; additionally, including a coarse wedge (30, 50) to take up the extra travel of a worn tool joint or a tubular of smaller diameter, with a means to ensure that the coarse wedge acts before the fine wedge (29, 49) does and a means to ensure that the wedging action remains if the actuating force is removed; additionally, including a secondary slips (40) to interfere with the upset on the tool joint to avoid relying on friction to support the string and a means of integrating this with the gripping slips and ensuring that the secondary slips act

Abstract: A method for drilling wells in which the tubular can be added or removed from the drill string whilst mud and drilling fluids being circulated continuously and kept separated from the environment to reduce pollution. A connector is used with an inlet and outlet for the mud etc. and which incorporates rams to seal off and separate the flow of mud as a tubular is added or removed.

Abstract: Methods and apparati are disclosed for continuous circulation of drilling fluids while adding or removing tubulars to and from a drill string, and also for continuing drilling during the addition or removal of tubulars to and from the drill string.

Abstract: A slips assembly which comprises a plurality of slip segments which, when positioned adjacent to each other, form a collar, which collar is larger than the diameter of the tubular body of the tubular at the top of the drill string and smaller than the diameter the upset shoulder of the said tubular, there being a segment moving means which can move the segments together to from a collar slidably located around the body of the said tubular, which slips assemblies can also be utilised in conjunction with, or as part of, the couplers referred to in prior patent applications, either to support, raise or lower the string below, or restraint, lower or raise the tubular, or stand of tubulars, above.

Abstract: A system and method is disclosed for continuously supplying drilling fluid down a bore hole while adding or removing tubulars.

Abstract: Methods and apparati are disclosed for continuous circulation of drilling fluids while adding or removing tubulars to and from a drill string, and also for continuing drilling during the addition or removal of tubulars to and from the drill string.

Abstract: A method for drilling wells in which the tubular (5) can be added or removed from the drill string (17) whilst the drill is rotating with the mud and drilling fluids being circulated continuously and kept separated from the environment to reduce pollution. A connector is used with an inlet (15) and outlet (10) for the mud etc. and which incorporates rams (11) to seal off and separate the flow of mud as a tubular is added or removed.

Abstract: Methods and apparati are disclosed for continuous circulation of drilling fluids while adding or removing tubulars to and from a drill string, and also for continuing drilling during the addition or removal of tubulars to and from the drill string.

Abstract: A method for drilling wells in which the tubular (5) can be added or removed from the drill string (17) while the drill is rotating with the mud and drilling fluids being circulated continuously and kept separated from the environment to reduce pollution. A connector is used with an inlet (15) and outlet (10) for the mud etc. and which incorporates rams (11) to seal off and separate the flow of mud as a tubular is added or removed.