Development Of Downhole Wireless Power Supply And Wireless Communication Intelligent Short Section

In the operation of a series of oil drilling operations such as drilling,well logging,and well completion,a large number of downhole intelligent instruments are needed to monitor downhole production parameters and provide scientific basis for dynamic analysis and development adjustment of oil fields.Due to the special downhole working environment,downhole intelligent instruments cannot use cabled power and communication in some cases,this project designed a set of downhole wireless power supply and wireless communication intelligence short sections to realize wireless power supply and two-way wireless communication for downhole intelligent instruments.The main work and research results of the paper are as follows:Aiming at the unfavorable conditions such as complex downhole structure and small installation size,comprehensive analysis of the current status of power supply and communication technologies and process requirements of downhole equipment is carried out.Because wireless power supply and wireless communication technology have no exposed electrical contacts,they have good insulation and corrosion resistance,and are suitable for downhole high water and oily environments.Magnetic induction coupled wireless power supply and Zigbee wireless communication method were determined.Through the theoretical analysis of the wireless power supply resonant circuit,the topology selection of the primary side circuit inverter is completed,and the selected circuit topology is simulated and analyzed,which provides the basis for the actual circuit parameter design and device selection.The ANSYS Maxwell finite element electromagnetic field simulation of the coil coupling mechanism in oil well steel structure and water environment was used to obtain the best coupling position and other important design parameters of the coil coupling mechanism.Completed the wireless power supply and wireless communication front-end(hereinafter referred to as the front-end)and the downhole wireless power supply and wireless communication end(hereinafter referred to as the end)of the hardware and software design,to achieve the wireless power supply and two-way wireless communication downhole smart instruments.The use of magnetically coupled wireless power supply technology enables wireless transmission of power from the front end to the end.ZigBee wireless communication technology is used to realize real-time two-way wireless communication between the front end and the end.The standard power output interface of the terminal and downhole smart instruments and the standard RS485(Modbus)communication interface are designed to facilitate the matching with downhole smart instruments.A self-adaptive adjustment hardware circuit and software program for wireless power supply is designed,and the transmit power can be adjusted adaptively according to the change of load power,which meets the power requirements of downhole intelligent instruments with different loads.The wireless power supply function for experimental testing in the laboratory water environment,the test result shows that 48 W wireless power supply can be provided within the allowable load range;The wireless communication function test in the water environment shows that the front-end,the end and the downhole intelligent instrument have normal three-level data communication,which can meet the production demand.