Changes in the composition of oil and water of a horizontal well developed by the method of thermogravitational drainage after its treatment with the GALKA® gel-forming system

The effect of the GALKA® thermotropic gel-forming system used to isolate the heat carrier in a horizontal well developed using the technique of thermogravitational drainage at the Lyael area of the Yaregskoye field is investigated. The data on changes in the composition of the produced oil and associated water are presented. Four-fold treatment with the GALKA® gel-forming system of every 80–100 m3 has provided an increase in oil production rates and a decrease in the water cutting of well production in 1.5–2 months. An increase in heavy polar components in the oil composition promoted a twofold increase in oil viscosity with a more complete recovery was observed. The episodic decrease in viscosity and asphaltene content, as well as the appearance of saturated hydrocarbons, are probably due to the involvement into development of a previously unsulated section with oil of a lighter composition. The appearance of ammonium and bicarbonate ions, an increase in the concentration of carbonates and chlorides and a twofold increase in the mineralization and pH of produced water from 7.1 to 9.7 suggests the presence of a gel-forming system in the composition of water.