1. Application background
In the traditional oil extraction process, only about 30% to 40% of the oil in the underground ** reservoir can be recovered. CO2 enhanced oil extraction technology is a technology that uses carbon dioxide to enhance oil recovery. The carbon dioxide in the industrial exhaust gas is collected and injected into the underground oil layer of the oilfield"expelled "out" and sealed in situ at the same time. Through CO2-enhanced oil extraction technology, the overall recovery rate can be increased to more than 50%, thereby improving the efficiency of oil resource utilization. According to 1 ton of carbon dioxide, 025 tons**, the annual increase in production is about 20 thousand tons, so as to achieve a win-win situation of oil production increase and carbon emission reduction.
CO2-enhanced oil extraction technology has many advantages. First, it can enhance the recovery of oil, which extends the service life of oil reserves. Secondly, carbon dioxide is an environmentally friendly, recyclable gas that does not pollute the environment. In addition, CO2-enhanced oil extraction technology can also reduce greenhouse gas emissions, which is beneficial to the fight against climate change. This technology is of great significance for building an "artificial carbon cycle" model and successfully helping China achieve the "double carbon" goal.
Second, on-site needs
CO2-enhanced oil extraction technology requires an in-depth understanding of the geological characteristics of oil reservoirs and the mechanism of action of carbon dioxide. There were 8 CO2 tankers on site, each with 4 liquid CO2 storage tanks, each equipped with a Siemens S7-200 Smart PLC at the tail. In the process of carbon dioxide injection, the S7-1500 PLC in the central control room closely monitors the flow, pressure, liquid level, temperature signal and other parameters in multiple liquid storage tanks on site, and displays them at the HMI end, which can optimize the injection parameters and fluid flow mode in real time.
Due to long-term exposure to high temperature, high pressure and corrosive substances, the pipeline of the oilfield is easy to be damaged by corrosion, and the replacement and maintenance costs are large, and the wiring is inconvenient. Therefore, the wireless mode is used to realize the wireless communication requirements between the carbon storage tank and the central control room, so as to reduce and reduce the occurrence of accidents and improve the safety factor.
Design requirements:1The Siemens S7-1500PLC in the central control room needs to monitor the flow, pressure, liquid level, temperature signal and other data in the carbon storage tank in real time during the carbon dioxide injection process.
2.The carbon storage tank uses Siemens S7-200Smart PLC to collect various parameters and remotely transmit them to the S7-1500PLC end of the central control room.
3.The distance between the central control room and the carbon dioxide tanker is about 200 meters, and there are steel frames and other barriers in the middle.
3. Wireless solutions
Due to the complex environment of the oil extraction site, there are great safety risks, and the design of the wireless solution also needs to take into account the simultaneous transmission of data from multiple tanks in order to monitor the phase change of carbon dioxide during the injection process in real time. Stable and high-real-time data interaction can adjust and maintain gas injection parameters in time to avoid affecting formation seepage and affecting the flow and recovery rate of oil.
Considering the above factors, Datai PLC wireless communication experts decided to use 33 pieces of Siemens PLC wireless communication terminal DTD418MB, through the RJ45 interface under the S7 protocol, to complete the PLC wireless Ethernet communication between the central control room and the tank 1 master and 32 slaves. A DTD418MB is installed at the S7-1500 PLC end of the central control room and the S7-200 Smart end of 32 carbon storage tanks to realize wireless data transmission between the central control room and 32 carbon storage tanks. It not only improves the exploitation and utilization rate of petroleum resources, but also has great significance for reducing carbon emissions and promoting the development of green energy.
Schematic diagram of the wireless communication scheme
Fourth, the benefits of wireless solutions
1.Save the transformation cycle and maintenance costs, and improve production efficiency: Eliminate the trouble of wiring maintenance, and greatly improve the operation safety, consistency and mining efficiency.
2.Multiple sets of wireless communication terminals are used at the same time without interfering with each other: The internal program of the wireless communication terminal adopts a channel to encrypt a single communication, even if multiple wireless devices work at the same time, there will be no interference between the devices.
3.Achieve a win-win situation of increasing oil production and carbon emission reduction: Significantly improve oil recovery, reduce carbon emissions, cooperate with and support the green and low-carbon sustainable development of petrochemical energy enterprises, and continue to make important contributions to the realization of the "dual carbon" goal.
4.Easy to install, ready to use: it can directly replace wired Ethernet cables, and is compatible with mainstream PLC communication protocols. Energized wiring is ready to use, no programming is required, and the electrician can install it.
5.Independent networking, no operating costs: The equipment adopts an all-digital wireless encrypted transmission mode, which does not rely on the cloud platform or factory LAN construction, and belongs to the wireless ad hoc network communication mode, and there is no operating cost in the later stage.