| In the later stage of NG(natural gas)well production,due to insufficient formation energy,the gas produced is difficult to carry and discharge the liquid at the bottom of the well.Severe bottomhole fluid accumulation will lead to a reduction in NG production.In recent years,the country has vigorously promoted the construction of digital oilfields,making Io T technology widely used in oil and gas fields.Connecting oil and gas well production equipment to the Internet can enhance the automation of the mining process and improve management efficiency.Plunger gas lift is a commonly used technology.The application of this technology is beneficial to the discharge of liquid accumulation in NG wells at the later stage of production and to increase production.However,the plunger gas lift equipment can only operate according to the set working cycle under normal circumstances,and cannot automatically adjust the working cycle as the conditions of the NG well change.And the plunger,as a mechanical device,cannot obtain the actual situation of the downhole in real time.In order to realize the intelligent adjustment of the plunger working cycle,this design adds two optimization control methods to the plunger gas lift controller: time optimization and casing pressure inflection point optimization.At the same time,sensors are installed inside the plunger to accurately obtain downhole conditions.The intelligent plunger system includes two subsystems,the surface and the downhole.The downhole data acquisition subsystem uses STM32L051 as the core,uses the PT100 temperature sensor and CY310 pressure sensor to collect data,and sends it to the ground plunger control subsystem via the RFID module after reaching the wellhead.The ground plunger gas lift control subsystem uses STM32F407 as the core,collects oil pressure casing pressure data through MODBUS,uses RFID module to obtain data from the downhole data acquisition system,detects the plunger signal reaching the sensor by interrupt mode,and sends this data to the cloud,displayed and operated using an LCD display and 4 buttons.The plunger arrival sensor uses STM32F103 as the processor,and the magnetic field near the oil pipe is detected by the RM3100 magnetic field sensor.After the plunger reaches the sensor,the magnetic field strength is collected one hundred times,and the average value is calculated,and 1.2times the average value is used as a threshold to judge whether the plunger reaches the wellhead.The host computer in the cloud can not only obtain the control parameters and collect the data of the plunger gas lift controller through the network,but also send the set control parameters to the site in real time and make them effective,and can also intelligently monitor the plunger failure.After field experiments,the ground plunger gas lift controller can operate stably in the field.Time optimization and casing pressure inflection point optimization can stabilize NG production by automatically adjusting the plunger working cycle,reducing bottom-hole liquid accumulation,and reducing the rate of NG production decline. |
