Abstract: Methods of testing circuits for degradation of electrical signals and compensating for this degradation are disclosed. One such method involves visually comparing a visual representation of a reference signal generated by a test signal source, which can be made substantially identical to an original signal, and a degraded signal generated by another test signal source after passing through a video system. The degraded image is then adjusted to visually match the reference image. Another disclosed method involves converting a degraded signal that has passed through a video system into two substantially identical copies of said degraded video signal and then adjusting one of the two substantially identical copies of said degraded video signal to compensate for the degradation of the system while comparing it with the other substantially identical copy of said degraded signal which remains uncompensated.

Abstract: Inflow regulation device for a production pipe for production of oil or gas from an oil- and/or gas reservoir (9), where the production pipe comprises a lower drainage pipe with drainage pipe sections (5) with one or more drainage pipe elements (2; 2a, 2b) having opening(s) (3; 3a, 3b) for inflow of oil and/or gas to an inner space (8) of the drainage pipe section. The inflow may be regulated by a movable sleeve (1) that abuts one adjacent side surface of the drainage pipe section (2; 2a, 2b) and where the sleeve is provided with a portion(s) (6) being able to cover/uncover the opening(s) in the drainage pipe element. The sleeve further comprises helical spurs/recesses (14, 15) that in conjunction with one adjacent abutting surface (18, 21) of the drainage pipe element (2; 2a, 2b) forms channels (16, 17) that may connect the reservoir (9) with the inner space (8) of the drainage pipe. The helical spurs/recesses (14, 15) may be constituted by one or more pair(s) of left- and/or right-oriented spurs/recesses.

Abstract: An injector (1) for injecting a traceable material into an oil and/or gas reservoir is lowered down into a bore hole that is in communication with the reservoir. An electro-hydraulic system is activated to inject a traceable material stored in a container into the reservoir. The injector is provided with a gland plate (7) that seals a space between the injector and the wall of the bore hole (16) in a manner that prevents traceable material from being distributed in the bore hole, but secures direct injection of the material into the reservoir. The injector is adapted to be positioned at a specific depth level in the bore hole, and to be cleaned by pressurized liquid after the injection operation is completed.