Research On Radio Frequency Technology Of Ground-Downhole Information Transmission In Oil And Gas Wells

Last decade,new technologies of oil and gas exploitation,represented by multi-stage layered hydraulic fracturing and guided drilling,have developed rapidly,which not only improves the operating efficiency of oil and gas Wells,but also greatly reduces the cost of well construction.These new technologies are centered on oil and gas downhole smart tools.However,how to achieve the data transmission of ground-downhole intelligent tools is still a"bottleneck"problem to be solved.Considering that the information transmitted to downhole intelligent tools can be simplified into some simple instructions,because the information has the characteristics of intermittence and small amount of data.This paper proposes the idea of using Radio Frequency Identification（RFID）technology to realize the ground-oil and gas well information transmission.The feasibility of the technology was discussed,and the technical scheme was put forward.The prototype of the principle was developed and the confirmatory experimental research was carried out.The main research results obtained are as follows:1^st.The principle of radio frequency technology is analyzed.The feasibility of RFID technology applied to oil and gas well information transmission is demonstrated.The frequency band characteristics of RFID is studied.The working frequency suitable for the working environment of oil and gas wells is optimized.2^nd.The difficulties of RFID technology in oil and gas well information transmission is analyzed.The overall scheme of ground-downhole information transmission system based on RFID technology is proposed.Low-frequency RF readers and RF electronic tags on the ground and underground are designed.The debugging of the circuits are completed,such as the power supply voltage circuit,Microcontroller module circuit,ground RF module circuit,underground high temperature RF module circuit,communication interface circuit and other hardware circuits.The corresponding functional software is developed.The RF reader antenna is designed and produced,and the prototype machine is made.3^rd.Aiming at the special environmental requirements of oil and gas wells,the miniaturization method and high temperature treatment technology of radio frequency electronic tags were proposed,and the micro-labels with outer diameter of 3.8 millimeters and length of 15.5 millimeters were developed.Verification tests on the prototype show that the tag can work reliably after heating at 105degrees Celsius,and in the high temperature water tank simulating the downhole environment,the RF reader can reliably identify the RF electronic tag to ensure the correct transmission of information.These research results provide a new technical idea for solving the problem of ground-downhole information transmission,and have practical application value.