Patent RU-2749658-C1 (RU)
Title: Method for developing high-viscosity oil deposits by cyclic steam method
Inventor: AKHMADULLIN ROBERT RAFAELEVICH
IPC: E21B7/04
Filed: 2020-11-20
Granted: 2021-06-16
Abstract: FIELD: oil field development.SUBSTANCE: invention relates to the field of oil field development. The method for developing a high-viscosity oil reservoir using the cyclic steam method includes drilling appraisal wells to delineate the oil-saturated reservoir and assess the potential for industrial development of the reservoir, testing the reservoir, studying oil samples, determining the viscosity of oil in reservoir conditions, building a horizontal well, pumping a coolant to warm the reservoir and then selecting products from wells. After the construction of a horizontal well, a tubing string is lowered with the end of the tubing located in the interval of the highest oil saturation of the horizontal wellbore. After the completion of the injection of the coolant, exposure is carried out for thermocapillary impregnation, geophysical studies of the well are carried out using the methods of thermometry and pressure measurement. According to the parameters obtained, as a result of geophysical studies, the point of high-viscosity oil withdrawal and the subsequent injection of the coolant are determined. Next, the equipment is lifted for the injection of the coolant and the assembly is lowered for the production of super-viscous oil and the injection of the coolant, including from the bottom up: a liner, an anti-rotation anchor, a screw pump, an expansion pipe, a mandrel, a pipe, a clamp, a tubing string, while parallel to the pipe between the mandrel and a clamp is used to install temperature and pressure sensors - TMS, then connect the TMS to the high-temperature cable and to the ground unit at the control station. High-viscosity oil is selected, with the help of TMS sensors, changes in pressure and temperature of the formation fluid, the environment, and also at the pump outlet are monitored. When the pump intake pressure is less than 2 atm and/or the liquid temperature is less than 40°C, the horizontal production well is transferred for injection. The planned volume of the coolant is injected up to the maximum allowable pressure not exceeding the hydraulic fracturing pressure. After that, the analysis of the formation temperature change is carried out using the TMS sensors and the analysis of the current pressure at the pump intake. When the pump intake pressure is less than 2 atm and the liquid temperature is less than 60°C, the coolant injection is resumed. With a pump intake pressure of more than 2 atm and a liquid temperature of 60-110°C, the well is transferred to production. When the pump intake pressure is more than 2 atm and the liquid temperature is above 110°C, the well is stopped for thermocapillary impregnation until the pump intake temperature drops to 110°C or less, after which the horizontal well is transferred to production. The injection and production cycles are repeated, after each cycle, the analysis of the formation temperature and the current pressure at the pump intake is carried out, the transfer of the well for injection or production is carried out by lowering or raising the assembly without lifting and changing the equipment layout.EFFECT: invention improves efficiency of reservoir development, reducing the period of thermocapillary impregnation and the total processing time, expanding and increasing reliability of the arsenal of technological means.1 cl, 3 ex