Development Of A Smart Underground Valve With Communication Cable

Combined with specific processing condition, the smart layered extracting technology, whose key technology is the accurate control of aimed valves, with the special geologic feature of offshore oilfields, guarantees the continuous, steady and efficient extraction of offshore oilfield.On account of the disadvantage of common valves, which cannot communicate in a twoway way, designed two solutions, one using PLC as a core controller on top of the well, the other using SCM as a core controller under the well. After a thorough and detailed comparison, concluded their features and utilizing occasions.For the solution whose controller is on top of the well, used PLC and relays to establish controller, motor drive, etc. hardware system. With its monitoring computer, power source and controller in a special box on top of the well, and its actuator down well, it s reliable, steady, and easily maintained. Using the protocol PPI, the monitoring computer and controller accomplish point-to-point communication.As for the other solution, designed SCM(single-chip microcomputer system), FSK modulation/demodulation, reducing voltage, motor drive, etc. circuits to establish the hardware system. Using DC power line carrier communication technology, signals are coupled to DC power line by FSK modulation/demodulation, achieving a two-way transmission of data and orders, accomplishing two-way communication with those controllers located in other layers of the same well. The distance of effective communication is 3,000 meters. Most importantly, just using one single cable core, this solution can power and communicate with multiple devices located in the same well, minimizing the cost effectively.With virtual instrument technology, the PC monitoring programs of those two solutions were designed by using modular design methods. Initialization of system data during the layered extraction process, real-time display and storage of those key data, sending of orders for layer selecting and replay of historical data, all can be realized easily.Laboratory tests indicated that both of the two solutions can achieve the goal accurately and reliably, which is controlling of the aimed layer flow underground and real-time monitoring of the well.