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 the column, successive formation of main process channels with the nozzle at the end over the perimeter of the casing column by means of the divertor, thus forming successively a group of main process channels over the perimeter of the casing column 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. Prior to being dropped into the well the flexible pipe is fitted with filters, the filtering openings of which are plugged with acid-soluble material. After formation of one main process channel the flexible pipe is disconnected from the pipe string and it is left in the process channel. Then the additional pipe string is withdrawn out of the well and fitted with the next flexible pipe with similar filters for formation of the next main process channel. On completion of formation of a group of main process channels 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 diverter 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 between them. 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.

3 dwg