Abstract: A method and apparatus for improving the performance of production-injection wells whereby a pump (35), driven by a hydraulic turbine (32) sharing the same central shaft (33, 34), is run and set in an oil-producing well. The oil enters the annulus of the well from the production zone and is induced into the pump to be forced to the wellhead; the injection water is forced down the wellbore to drive the turbine whereafter the injection water exhausts through the pump to be injected into the underlying aquifer thereby providing additional pressure support to the producing zone.

Abstract: The invention relates to a bridging platform arrangement (20) for bridging a gap (16) between a railway rail (10) and an adjacent ground surface (14). The bridging platform arrangement (20) includes a bridging plate (58) and a mounting arrangement for mounting the bridging plate (58) between the railway rail (10) and the ground surface (14). In use, the mounting arrangement permits displacement of the bridging plate (58) between two positions—a first rest position in which the bridging plate (58) extends between respective upper surfaces of the railway rail (10) and the ground surface (14); and a second displaced position in which the bridging plate (58) is displaced below the first position so as to not interfere with the passage along the railway rail (10) of a wheel (1) of a railway vehicle.

Abstract: The invention relates to a bridging platform arrangement (20) for bridging a gap (16) between a railway rail (10) and an adjacent ground surface (14). The bridging platform arrangement (20) includes a bridging plate (58) and a mounting arrangement for mounting the bridging plate (58) between the railway rail (10) and the ground surface (14). In use, the mounting arrangement permits displacement of the bridging plate (58) between two positions—a first rest position in which the bridging plate (58) extends between respective upper surfaces of the railway rail (10) and the ground surface (14); and a second displaced position in which the bridging plate (58) is displaced below the first position so as to not interfere with the passage along the railway rail (10) of a wheel (1) of a railway vehicle.

Abstract: A method and apparatus for improving the performance of production-injection wells whereby a pump (35), driven by a hydraulic turbine (32) sharing the same central shaft (33, 34), is run and set in an oil-producing well. The oil enters the annulus of the well from the production zone and is induced into the pump to be forced to the wellhead; the injection water is forced down the wellbore to drive the turbine whereafter the injection water exhausts through the pump to be injected into the underlying aquifer thereby providing additional pressure support to the producing zone.

Abstract: A double-barrier metal-to-metal seal assembly includes a seal gasket (3) having an outer flexible seal element (6) and an inner flat rib (8). The assembly also includes a pair of hubs (4, 5) each having an internal machined profile characterised by a tapered profile (7) which, when the hubs (4, 5) are mechanically set, provides an interference fit against the outer flexible element (6) of the seal gasket (3) so as to provide an outer seal, and an inner profile (9) comprising a plurality of concentric circular nibs (9) machined on the hubs (4, 5) which, when the hubs (4, 5) are being mechanically set, progressively embed themselves (9) to a pre-determined depth into the rib (8) of the seal gasket (3) to effect an inner seal. The embedment is limited by the face-to-face abutment of the hubs (4, 5) outside the locus of the outer seal during the mechanical imposition of preload.