The procedure for bringing the oil wells on to stable production, equipped with the electric centrifugal pumps units, is strictly regulated by normative documents and requires periodic monitoring of the fluid inflow rate from the reservoir needed for cooling the submersible electric motor. Evaluation of the electric motor temperature regime can be carried out either using special deep sensors of the thermomanometric system or, in the absence of such sensors in the pumping unit, by indirect measurements, the most common option, which is the measurement of the liquid level in the space between the production string and the well tubing (annulus) by an echo sounder, the well flow rate by the automatic group metering station, the buffered pressure and gas pressure in the well annulus. In some cases, direct measurement of the flow rate or liquid level in the well annulus without the thermomanometric system sensors readings is impossible. In particular, this situation occurs for wells, which are being developed after drilling, current repair or workover.
The considered problem statement of calculating the absent flow rate parameter or fluid level in the well annulus during the well development in the proposed article is simplified, which makes it possible to obtain an analytical expression linking the well flow rate with the fluid level in the annulus and with the electrical parameters of the submersible electric motor of the pump unit. The use of this analytical expression as a basis for the development of the "virtual flow meter" algorithm allows, by interpreting the measured electrical parameters of the submersible electric motor of the pumping unit and the parameters of the liquid level in the well annulus, to carry out a rapid assessment of the well flow rate. The solving the inverse problem (at a given well flow rate) makes it possible to estimate the missing parameter of the fluid level in the well annulus, which is necessary to assess the fluid inflow from the reservoir. The estimation of the calculation accuracy using the "virtual flow meter" algorithm was carried out by comparing the calculation results with the data from the process flow charts for bringing the pump on to stable production for wells in the West Siberian region.
References
1. Pashali A.A., Aleksandrov M.A., Kliment'ev A.G. et al., Automatization of collecting and preparation of telemetry data for well testing using ''virtual flowmeter'' (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 11, pp. 60–63.
2. Pashali A.A., Topol'nikov A.S., Mikhaylov V.G., Flow rate retrieval on the basis of algorithms of the “virtual flowmeter” for wells testing (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2017, no. 11, pp. 63–67.
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