DEWAXING METHOD OF OIL PRODUCING WELL Russian patent published in 2013 - IPC E21B37/06 

FIELD: oil and gas industry.

SUBSTANCE: dewaxing method of an oil producing well involves creation in a wax deposition zone of temperature exceeding wax melting temperature by pumping to the well of components interacting with heat emission, carryover of reaction products and molten wax from the tubing. First, there built are curves of temperature distribution of a borehole flow at intervals of the production casing from the working face to pump suction and the tubing string from the pump to the head considering determination of liquid temperature at pump discharge, curves of pressure distribution in the well at the above intervals and curves of oil saturation temperature with wax in the well considering pressure change in the well and gas content of oil during lifting of gas-liquid mixture according to the following formula: t_oi=t_od+A_l·P_i/P_sat-A₂G_i,/G₀, where t_oi - saturation temperature of oil with wax in the well; t_od - saturation temperature of degassed oil; P_i - a number of successive pressure values at the specified interval, MPa; P_sat - saturation pressure of oil with gas; G_i - gas saturation of oil at corresponding pressure values P_i and temperature T_i, m³/m³; G₀ - gas content of oil at pressure P_sat; A₁ and A₂ - correlation coefficients depending on oil composition and properties. As per the built distribution curves at cross point of temperature of the borehole flow and saturation temperature of oil with wax there determined is depth and thermodynamic conditions of intensive waxing in the well. Then, considering the determined conditions, number and concentration of components are chosen for carryover of molten wax.

EFFECT: improving efficiency of struggle with asphaltene-resin-wax-bearing deposits.

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