A Comprehensive Well Control Intelligent Control System and its Application

Abstract Tremendous amounts of oil and gas reservoirs are located in ultra-deep formations, which were generally buried deeper than 8,000m in Sichuan Basin and Tarim Basin of China, in some blocks the oil and gas exploration has been expanded to 9,000~11,000m. The geological conditions are complicated, and the formation fractures and cavities which resulting a series of drilling safety problems. With the rapid development of automation and intelligence technology in drilling engineering, the new generation of well-controlled intelligent equipment for ultra-deep wells' drilling safety is significant. Firstly, an early kick detection method was proposed based on the pressure derivatives and multi-parameters artificial intelligence pattern recognition. The pressure derivative is used to amplify the small changes of pressure during the whole drilling and accurately identify the kick time, the characteristics of parameter changes such as outlet flow rate and pit gain under different working conditions can be used to confirm influx volume. To achieve the high-pressure working range precise adjustment, a cylindrically curved surface structure choke was designed with a pressure drop linear variation characteristic during 30%~70% opening range, furthermore, a novel integrated servo electric actuator was developed which can output 21 tons thrust continuously and stably, based on which the choke working pressure can be achieved to 50MPa. Moreover, a fully electric modular automatic control equipment for well control has been developed, which has the function of fully automatic control for managed pressure drilling (MPD) and well control with two automatic choke channels of 35MPa and 105MPa. Furthermore, the coordinated control process of various parameters was clarified for well control based on the multi-parameter matching relationship, and then an intelligent control method for flow rate, standpipe pressure, and wellhead pressure interconnection adjustment was established, through which the well kick parameters can be automated control easily. The proposed well control intelligent control system has been applied in Q block of SINOPEC, the kick can be detected as less than 80L and there is an excellent match between the simulation and measured data, the pressure adjustment error is less than 50 psi for well killing. Furthermore, the simulation software has been used for designing the well-killing parameters and it runs smoothly with convenient operation. Therefore it can be seen this system can be applied to provide more convenience and safety for well control. This study proposed a comprehensive well control intelligent control System, through the application we can adjust multi-parameters in real-time while well killing, and this well control intelligence has been applied in several wells very well. Therefore, this study is novel and can afford effective automated equipment for well control.