METHOD OF VISUAL CONTROL OF SCREWING OF THE COUPLING OF OIL AND GAS FIELD PIPES Russian patent published in 2019 - IPC E21B17/00 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil industry and can be used for multiple screwing and unscrewing for control (visualization) of the relative position of the nipple and coupling elements, corresponding to the end of the screwing-up of the threaded joint of pipes, mainly extracted from the well. Method of visual inspection of screwing the coupling joints of oil and gas field pipes with a male end with male thread and with a female thread coupling, wherein the marks are applied with a threaded grease mixed with a pigment contrasting with the color of the application surface. Contrast marks are applied in a continuous layer, evenly distributing along the internal thread and external thread until the thread is tapped, until the color of the application surface disappears under the contrast mark. Visual control of screwing is provided until the moment of screwing completion, at the moment of disappearance of the entire contrast mark of the nipple end, along with a thread runoff under the outer end of the coupling.

EFFECT: improving the reliability of sealing coupling threaded connections.

1 cl, 3 dwg