WELL AND WELL OPERATION Russian patent published in 2002 - IPC

FIELD: construction, repair and operation of water intakes of underground water, water supply systems, oil and gas industry. SUBSTANCE: well includes operational string of pipes, outer and inner perforated pipes of filter with plugged lower but of outer pipe and filtering backfill of granulated material in zone close to filter and between them installed uneasily with operational string of pipes, transducer of dynamic level of water, member to remove sand and sediment. The latter has feed-drain pipe-line, jet-type pump, solenoid valve, element transmitting vibration to tubular backfill. It includes submersible pump and springs. Element transmitting vibration has bearing flange on shoe of operational string. It is combined with foam polystyrene filter-gland placed in enclosure. Non-perforated part of filtering string is mounted freely for movement on spring, its movement is limited by thrust flange. Perforated part of string is located between water confining strata with lower end of settler in the form of hemisphere " floating " in water-bearing horizon and held in static state in vertical position on shoe of operational string of pipes thanks to own weight and formation pressure. In periods of regeneration of backfilling and pouring of filtering material perforated part is given free vibrations and displaces due to action percussion element transmitting vibration. It includes striker- cylinder, spring, thrust journal-bushing, spring bullhead, cable, cable drive switched on by signal from standby and master transducers of dynamic level of water in observation and production wells. It excludes false switching on of regeneration mechanism caused by drop of water level in water-bearing horizon proper and not in zone close to filter because of collimation. In correspondence with invention periodic regeneration is conducted by water hammer under automatic condition advancing collimation under variants of passive and active regeneration. Passive regeneration is automatically conducted constantly during operation of pump and change of pressure in water supply system by water distribution point. With this in mind pressure in well water-lifting pipe is changed by submersible pump owing to change of water distribution in external water supply and to limited discharge of well in time intervals 6-9 and 17-20 hours of maximum water distribution and in time interval 0-3 hours of maximum transit of water into water tower. This alters porosity of backfill around filtering string traveling on spring thanks to compression or stretching of spring. During regeneration conditions preventing sand clogging, formation of sediment and closing of sand washout cavities are created. Active regeneration is carried out by single or several cycles described below by specified program or manually with time- intensified processes of colmatage. Periodic short-time switching off of submersible pump and momentary, 0.1 s controlled planned water hammer on return valve, its disc and body advancing colmatage is fed with this in mind. By it filtering string is displaced on spring. Vibration load is applied normally to axis of pipe to internal lower part of settler of filtering string freely " floating " in water-bearing horizon with the aid of vibrator for time of 5 min or under in advance to water hammer for time minimally required to diminish side cohesive force between filtering string and backfill. EFFECT: prevention of colmatage in zone near filter and in well filter in process of water production by longitudinal and lateral movement of filtering string and its backfill caused by vibration. 5 cl, 11 dwg