The article considers the urgent issue of predicting the process of salt deposits formation during the operation of electric submersible equipment in wells. The physicochemical properties of produced waters of high-temperature deposits in the Oktyabrsky district of the Krasnoleninsky arch are given. The process of calcite precipitation is described when the thermobaric equilibrium in the formation fluid changes. In the formation waters of igneous rock the presence of ferrous ions was detected, which contributes to the formation of iron carbonate deposits. At present, predicting the iron carbonate precipitation in wells with an isothermal anomaly is difficult because of the heterogeneous structure of volcanic rocks and requires additional research.
To assess the risk of calcium carbonate precipitation by the value of the saturation index, we adapted the Oddo – Thomson’s method in r to the conditions of deposits of the Krasnoleninsky arch. In the Oddo – Thomson’s method reservoir temperature is used for calculating the saturation index. We propose to use temperature of pump. When operating wells with a high content of free gas at suction of a pump, the rate of heat generation increases, while the cooling rate of the pump decreases. This is leads to pump overheating. Increasing the temperature of the pump in this case significantly affects the process of salt formation. We made comparative analysis of the results of prediction of the salt deposits formation before and after adaptation of Oddo – Thomson’s method to the conditions of the deposits of the Oktyabrsky region. It is shown that the adaptation of the method allows more accurately determine the levels of danger of salt deposition depending on the saturation index.
References
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3. Gareev A.A., On the temperature regime and the thermal shock phenomenon in an electric centrifugal pump (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2011, no. 3, pp. 122–126.
