METHOD FOR DEVELOPMENT OF HIGH-VISCOSITY OIL DEPOSITS Russian patent published in 2010 - IPC E21B43/24 E21B7/04 E21B43/10 

FIELD: oil and gas production.

SUBSTANCE: invention relates to method for development of high-viscosity oil deposits with application of its heating. Concept of the invention is as follows: main well is arranged according to method. For this purpose the main borehole is drilled, afterwards casing pipe string is lowered in it, and cementing is carried out from bottomhole to wellhead to form a cement ring. Then lower part of main well is drilled in the form of horizontal section arranged in payout bed. Over horizontal section of the main well, within this payout bed, side horizontal borehole is drilled. Afterwards packer is installed in the main well below interval of side horizontal borehole cutting with the help of pipe string. Packer seals space between lifting pipe and casing pipe string of the main borehole of the main well. Lifting pipe string (LPS) assembly is started. At the same time it is equipped with tubular filter and nipple with whipstock arranged above, provided with window arranged in wall of lifting pipes over nipple, and bypass channel, inlet of which communicates with over-wedge space of lifting pipe string, and outlet - to under-packer space of lifting pipe string. Afterwards lifting pipe string is lowered into main borehole of main well until nipple tightly interacts with packer with arrangement of tubular filter in horizontal section and arrangement of window opposite to cutting interval of side horizontal borehole above packer. Then perforated string is lowered on process pipe with additional packer via lifting pipe string, whipstock and window into side horizontal borehole until perforated pipe string is located in its horizontal section. Then additional packer is installed between lifting pipes and process pipe over window, but below inlet of bypass channel. Pump is lowered into process string on rod string and is arranged over perforated string. Then well is put in operation, at the same time, pumping of coolant, for instance water steam, into main borehole of main well is carried out along tube space of lifting pipes and process pipes string, bypass channel, under-packer space of lifting pipe string and filter. In side horizontal borehole coolant arrives into payout bed, and as it lifts upwards, it heats payout bed, liquefying high-viscosity oil. Heated high-viscosity oil via perforated string arrives to suction of pump, which pumps high-viscosity oil along process pipe string onto surface. Since coolant is pumped in tube space between process pipe string and lifting pipe string, direct contact of coolant with walls of casing pipe string, and accordingly, with cement ring, is eliminated, which, in its turn, reduces heat losses as coolant is pumped into payout bed.

EFFECT: increased efficiency of method due to reduction of heat losses by coolant in well and direct exposure of well walls to heat in process of deposit development.

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