METHOD FOR MULTILATERAL WELL CONSTRUCTION Russian patent published in 2008 - IPC E21B7/06 

FIELD: oil and gas production industry, particularly to construct oil and gas well clusters.

SUBSTANCE: method involves lowering pipe string in casing pipe in predetermined interval, wherein pipe string has whipstock to be retained with respect to casing pipe so that the whipstock may rotate through predetermined angle; serially cutting windows in casing pipe along casing pipe perimeter by means of cutter secured to flexible shaft end with the use of whipstock to create technological channels in productive reservoir; removing flexible shaft; serially creating technological channels having necessary lengths along casing pipe perimeter with the use of flexible pipe provided with nozzle at one end thereof and adapted to supply high pressure liquid to create technological channel group along casing pipe perimeter. After flexible pipe provided with nozzle removal from well the nozzle is substituted for fan-like nozzle. After that flexible pipe having fan-like nozzle is lowered in well up to contact with whipstock. Then each technological channel is reamed with the use of flexible pipe with fan-like nozzle by liquid injection through the flexible pipe with the nozzle. After flexible pipe provided with fan-like nozzle removal from pipe string whipstock is detached from casing pipe and fixed over or under initial whipstock location so that whipstock may be rotated through predetermined angle. Then additional windows are cut in casing pipe and additional technological orifice row is created within next production reservoir in the same way. After that other additional windows are serially cut in casing pipe in the same way to create and ream further additional technological channels within the limits of next productive reservoirs to be penetrated.

EFFECT: decreased material consumption and costs due to elimination of additional well constriction in heavy oil reservoirs, possibility of different horizon penetration with single well.

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