METHOD OF CATHODIC PROTECTION OF A WELL EQUIPMENT AND A DEVICE FOR ITS REALIZATION Russian patent published in 2004 - IPC

FIELD: petroleum industry.

SUBSTANCE: the invention is dealt with methods and devices for protection of the well equipment, including the deep-seated equipment, in particular, electrical centrifugal pumps (ЭЦН) from rust with superposition of a controlled difference of potentials and may be used in petroleum industry. The technical result is an increase of a cathodic protection of the well equipment without decrease of efficiency of protection in spite of the change of its depth in the well. The method provides for superposition of a difference of potentials between a terminal of a cable connection to the casing string on the day time surface and the anodic earth electrode and additionally - of the difference of potentials between the foot point of the well equipment and the anodic earth electrode. The difference of potentials between the foot point of the well equipment and the anodic earth electrode is imposed through the terminal point of the cable connection to the casing string on a day time surface. For a cathodic protection of the well equipment with a centrifugal electric pump (ЭЦН) the difference of potentials between the foot point of the well equipment and the anodic earth electrode is imposed with application of an additional core of the power cable of the a centrifugal electric pump. The station of the cathodic protection may be follow-up connected to the foot point of the well equipment by one- , two- or three-core power cable.

EFFECT: the invention allows to increase the cathodic protection of the well equipment without decrease of its efficiency of protection in spite of the change of the equipment depth in the well.

7 cl, 1 dwg, 2 tbl, 2ex