DEVICE FOR THERMAL INSULATION OF STRING Russian patent published in 1998 - IPC

FIELD: oil production industry. SUBSTANCE: this can be used in operation of oil and gas wells with intensive creation of paraffin and hydrate. Device is made up of string of external pump-compressor pipe. Installed inside this pipe string is internal pump-compressor pipe string with casing centralizers. Mounted on pipe string is centrifugal pump, and installed above centrifugal pump on pipe string is ejector. Ejector incorporates working nozzle and confuser. Both of them together create receiving chamber which through valve is connected with annular space. Confuser of ejector is converted into mixing chamber in the form of telescopic joint with its external part being connected with confuser of ejector. Internal part of telescopic joint through diffuser is connected with internal pipe string. Located below mounting place of ejector on external pipe string is circulation valve which connects enclosed annular space with hole clearance. Internal and external strings of pump-compressor pipes in their lower parts are connected to each other by means of seat and cone pair. For engagement of telescopic joint at lifting of ejector to surface, stops are rigidly connected to internal pipe string and to external part of telescopic joint. Working nozzle of ejector is connected with outlet of centrifugal pump through pipe string. Aforesaid arrangement of components improves efficiency of device operation which is supplement with simplification of its overall design. EFFECT: higher efficiency. 1 cl, 4 dwg 1 cl, 4 dwg