As per API RP11S5, cable armor is the outer covering of the cable which provides mechanical protection during installation and removal of cables. In addition to mechanical protection, the armor provides mechanical constraint against swelling and expansion of underlying elastomeric materials in case of any exposure to well fluids.
As per API RP11 S5, supplementary layers of materials, named: braids and coverings, are used to guarantee a specific mechanical performance characteristics. It could be either applied over the insulation or on both sides of the jacket. Braids and coverings provide additional strength and protect the underlying cable components. On the other hand, these materials increase the cable diameter and the associated cost. Furthermore, they are also susceptible to deterioration depending on well fluids and conditions.
As per API RP11S5, cable jackets are protective coverings used to mechanically shield the insulation from the downhole environment. The jacket materials protect the insulation from mechanical abuse associated with handling. Some jacketing material may provide secondary insulation. The most used types of jackets in submersible pump cable are made of: EPDM elastomers or nitrile.
As per API RP11S5, cable insulation isolates the electrical potential between conductors and other conducting materials. Insulation also minimizes leakage current from the conductors.
Insulation selection depends on many factors mainly related to produced fluids properties and well behavior; such as: gas type and concentration, well environment, gas to oil ratio, pressure cycling, exposure to downhole chemicals…
There are two classes of cable insulation materials used in oil and gas industry:
The AC current is carried from the surface to the motor using either copper or aluminum cable conductors. For ESP applications, four sizes of conductors have been standardized: #1, #2, #4 and #6 AWG.
AWG stands for “American Wire Gauge”.
Power losses and operating temperature decrease by increasing the conductor size for a given current. Moreover, for a given conductor size increasing current will increase both the power losses and cable operating temperature.