Separated layer production is an effective means to mitigate inter-layer problems, minimize invalid water circulation and improve oilfield production efficiency. A non-contact connection separated layer production technology is developed in this paper to realize the automatic monitoring and control of production wells.

By developing a downhole production parameter monitoring and CPU management system, acquisition of downhole pressure, flow and temperature data, control of flow control valve opening, and saving of historical test and adjustment data into downhole system can be realized. A downhole communication sub is used for signal transfer. The ground and downhole communication sub communicate with each other via power line carrier, while the downhole communication sub makes wireless communication with the downhole automatic control system. Downhole charging from the ground is realized by utilizing the non-contract charging type power supply system.

An oil well test study is carried out based on this technology. The maximum temperature of the test well is 82°C, and the water cut is 96.8%. With successful downhole non-contact connection, stable and reliable data transmission at a rate of 9,600bps, and no data packet loss during communication, the test results have verified the feasibility of this technology and the realization of automatic monitoring and control of downhole working conditions. The downhole charging current is 7.4A, and the electric energy conversion efficiency is 31.4%. According to calculation results, the battery can be used for more than 20 times of automatic allocation of production flow. The adjustment interval is set at one month and the system can work continuously for more than one and a half years under this condition.

In this paper, the technical problems of non-contract charging and wireless data transmission in high temperature downhole environment are solved successfully, and a downhole separated layer production automatic control system is developed.

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