METHOD FOR TREATMENT OF A DEPOSIT OF HIGHLY VISCOUS OIL Russian patent published in 2007 - IPC E21B43/20 

FIELD: oil and gas extractive industry, in particular, technologies for increasing efficiency of extraction of highly viscous oil deposits.

SUBSTANCE: method includes drilling primary pilot boreholes for future product and force wells with opening of productive formation. Water is forced in, pressure change in borehole of product well is registered, water forcing is stopped after upsurge of face pressure, being a sign of massive structure of productive formation within limits of extraction element being researched. Aforementioned element is drilled with vertical and/or horizontal product and force wells with area positioning system thereof. Faces or boreholes of wells are distanced so that product wells are used to open the productive formation near its ceiling, while force wells are used to open the productive formation either above or below the water-oil contact. Oil is displaced in vertical direction with forcing mode of working agent, primarily water, based on condition that current formation pressure in extraction element is not lower than original formation pressure. Forced into force wells is water thickened with polymer on condition of prevention of premature influx of working agent into product wells. In accordance to second variant, faces or boreholes of wells are distanced so that at first stage product wells are used to open the productive formation approximately in the middle, and at second stage side horizontal shafts are drilled close to ceiling of productive formation.

EFFECT: increased efficiency when extracting a deposit of highly viscous oil.

2 cl, 1 ex, 2 tbl, 4 dwg