METHOD OF CONSTRUCTION OF MULTI-SHAFT WELL FOR RECOVERY OF HIGH-VISCOSOUS OIL Russian patent published in 2008 - IPC E21B7/04 E21B43/02 

FIELD: petroleum industry.

SUBSTANCE: invention relates to oil and gas production industry, particularly to construction of oil and gas well clusters in underground maltha sand deposits and heavy high-viscosity oil fields. The method includes dropping a pipe string with a divertor at its end into the casing column within the interval required, cutting the casing column, successive formation of main process channels over the perimeter of the casing column by means of a flexible pipe with the main nozzle at its end, thus forming successively a group of main process channels by turning the divertor. The casing column is cut by the cutter over the whole perimeter of the column in two places so that it is possible to form process channels within one seam. The divertor is fixed in the casing column so that outlet openings of main process channels are arranged within one slot in the casing column. After formation of main process channels filters are inserted into the well on the additional pipe string into the same process channels with the aid of the diverter, the filters being tightly plugged from inside with an acid-soluble material. The filters are interconnected by flexible links with an additional nozzle, through which a hot liquid or steam is injected. Then they are disconnected from the additional pipe string, which is withdrawn for connection with the following similar filters to be inserted into the next main process channel. After equipping all main process channels with filters the divertor is released and is fixed below or above the initial place of mounting in the casing column so that it is possible to turn it through a certain angle and to form additional group of process channels similar to the main ones with additional filters within the limits of the second slot in the casing column. On completion of formation of the group of additional process channels and withdrawal of the divertor out of the casing column acid is injected into the process channels for dissolution of acid-soluble material. Next the process pipe string is lowered into the casing column and a packer is mounted. The invention provides reduction of material and financial costs and increased efficiency of operation of the multi-shaft well.

EFFECT: reduction of material and financial costs and increased efficiency of operation of the multi-shaft well.

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