Abstract: A pump is installed in a drill string above the bit and both the bit and pump are connected to the outputs of a differential gearing located therebetween. The circulation of drilling fluids is the reverse from the conventional and by operating a valve in the drill string the torque applied to the bit and pump can be controlled. Useful for drilling weak formations.

Abstract: In a method of and apparatus for laying and connecting a flow line to a submerged base structure, wherein the end portion of the line for connection to the submerged base structure comprises an elbow portion and a connection at the end of the elbow portion, which connection is capable of pivoting about the axis of the elbow portion and forms part of a basic structure for vertical connection to the base structure, the basic structure is held fixed relative to the end portion of the line by operation of a locking apparatus rigidly connecting the elbow portion to the connection, the collector line is progressively submerged in alignment with the submerged base structure until the basic structure coincides with connecting means on the submerged base structure, and the locking apparatus is unlocked so that the elbow portion of the line can pivot freely about its axis relative to the basic structure.