Abstract: A downhole corrosion monitor comprises a sensor head suspended on a cable, the cable being extensible so as to raise and/or lower the sensor head downhole and having a signal conductor to return data from the sensor head to the surface, the sensor head comprising a plurality of mutually insulated electrical sensors and means for detecting the voltages and/or currents existing therebetween. The electrical sensors can detect corrosion rate by one or both of linear polarisation rate and electrochemical noise and thus there will usually be at least three. The sensor head can further comprise sensors for at least one of temperature, pressure, vibrations, acceleration, flow sand rate and water cut. A corresponding method of obtaining data is also disclosed, together with a method of designing an item of downhole equipment and the item of downhole equipment thus designed.

Abstract: A subsea raw water injector including a pump which is connected to an injection string and a filter connected to an inlet of the pump to remove particulates from the surrounding sea water. The filter is in the form of an inclined tube settler disposed such that particulates separated from sea water flowing through it are discharged to the seabed.

Abstract: A method and apparatus for detecting and measuring localized corrosion of a metallic surface is described. An array of electrodes fabricated from the same material as the metallic surface is exposed to the same corrosion conditions as the metallic surface. The coupling current between two electrodes of the array is measured, and the electrochemical current noise originating in the electrode array is measured. The two measurements are compared, the electrochemical current noise increasing as compared to the coupling current as the degree to which corrosion is localized increases. The electrochemical current noise originating in the coupled array electrode and the associated electrochemical corrosion potential noise are produced by the natural corrosion processes.