Field Testing of Submersible Cable
The increased number of installations of submersible pumps in the oilfield has brought about an increased need for decreasing the operating costs associated with the cable. The devices and methods of field testing the cable are explained, and the results of application of different testing parameters and techniques are evaluated. The effect of temperature on the insulating material is presented. Specifications and standards for manufacturing and factory testing of submersible cable are also discussed.
Can present field test technology reasonably determine cable quality
One of the most controversial issues in the field of cable technology involves trying to determine the status of used cable. There is no consensus within the industry or even among the so called "experts" as to how this decision should be made. This paper identifies methods and limitations of techniques used by different organizations. These range from recommended practices to company guidelines. A model for insulation is presented. The results of the model are compared with common criteria used to evaluate cable. Criteria for any installation are addressed. Detailed analysis is applied specifically to an electric submersible pump (ESP) cable.<<ETX>>
Microstructure of the solder-casting zone in bridges of dental gold alloys.
The composition and structure were studied in the cast and in the solder of bridges which had failed clinically. Both materials were gold alloys but with different contents of Pt, Ag and Zn. The metallographic investigation revealed defects mostly in the solder, situated in the subsurface layer. SEM studied of the fracture surface revealed large porosites and a structure of dense parallel lines--striations--, indicating that the material had failed from fatigue. The materials in the fractured bridges were identified by micro-probe measurements. It was stated that cast material and solder material used together, were of different composition.