METHOD FOR DEVELOPMENT OF FORMATION WITH HIGH-VISCOSITY OIL Russian patent published in 2016 - IPC E21B43/241 

FIELD: oil and gas industry.

SUBSTANCE: invention can be used in development of beds with high-viscosity oil and presence of bottom water of small thickness. In method of developing formation with high-viscosity oil collector is exposed with main vertical shafts of wells drilled from them side horizontal shafts, development of side horizontal shafts, pumping of working agent and extraction of products through side horizontal shafts. Invention comprises selecting section of formation, saturated with oil with dynamic viscosity more than 400 MPa·s, with water-oil zone, where thickness of oil part formation exceeds 10 m, and water-bearing - is not more than 5 m. From vertical well is drilled from side horizontal shafts descending profile with distance from side horizontal shaft tip to oil-water contact of at least 2 m, side horizontal shaft length is not less than half distance between vertical wells or half size being well pattern. Side horizontal shaft is conditionally divided into sections with length of 10-50 m, each section separately, for which is lowered to side horizontal shaft pipe string with filter at double packers with length of not more than length of corresponding sections through pipe string and filter is pumped into bed in each section heated to temperature not less than 50 °C at bottom of solvent in volume V_n=(1…50)·l_n·m_n, where l_n is length of n-th section, m_n is porosity of formation opposite to n-th section. After thermocapillary impregnation with solvent section is allowed for pumping of liquid, each section of same way, after which entire shaft is put into operation, well operation is performed in cyclic mode selection-pumping: after reduction of oil flow rate by more than 50 % of initial oil flow rate after previous pumping cycle is pumping of solvent throughout length of barrel in volume equal to ∑V_n, at that solvent is pressed by flush fluid with temperature not less than 50 °C at bottom with increase in volume of this liquid after each cycle at 10-20 % at drawing of bottom water and watering of well by more than 95 % lower section is cut off in series with packers.

EFFECT: higher rate of oil extraction and oil recovery factor of formation with high-viscosity oil.

1 cl, 1 dwg, 2 ex