Abstract: A method of locating a drilling apparatus and/or a borehole in a subterranean region. The method may include the steps of transmitting seismic waves into the subterranean region during a subterranean drilling operation, the seismic waves being transmitted from a location remote from the drilling apparatus, detecting a seismic response from the drilling apparatus or borehole, and comparing the detected response with predetermined seismic survey data of the subterranean region to determine the location of the apparatus or borehole.

Abstract: A subsea mud pump can be used to return heavy drilling fluid to the surface. In order to provide a less stringent requirement for such a pump and to better manage the bottom hole pressure in the case of a gas kick or well control event, the gas should be separated from the drilling fluid before the drilling fluid enters the subsea mud pump and the pressure within the separating chamber. The mud pump suction should be controlled and kept equal or lower than the ambient seawater pressure. This can be achieved within the cavities of the subsea BOP by a system arrangement and methods explained. This function can be used with or without a drilling riser connecting the subsea BOP to a drilling unit above the body of water.

Abstract: The invention relates to a method and a device for determining the thickness and topography of buoyant objects, especially ship's hulls (1), by means of a beam (2, 17) carrying an array of ultrasound sensors (3). The object (1) and the beam (2) are moved relative to each other in the object's longitudinal direction while the distance between the object and the beam are automatically adjusted by raising/lowering the beam (2) by means of lifting means (6) and/or distance elements secured by floating bodies (4). The invention also relates to a device for implementing the method.

Abstract: A drilling riser for use at great sea depths for drilling of wells in the seabed using a drill string, with the drilling riser arranged to be connected between a wellhead at the seabed and a vessel, and arranged for use with a drilling fluid with sufficiently high density to balance the fluid pressure from the geological formations, with a sensor arranged to detect the level of the drilling fluid's level in the drilling riser, and a return riser pipe with an adjustable return riser pump. The return riser pipe extends up to the vessel, from an outlet on the riser, from a depth which is substantially below the sea surface, and at the same time at a height substantially above the seabed.