Research On Verification System Of Downhole Processing Algorithm For Acoustic Logging Data

The current acoustic logging while drilling method cannot meet the needs of downhole closed-loop control and geosteering.It is a general trend to upgrade the current downhole tools and develop downhole processing algorithms.The current algorithm is mostly implemented in the pure software of the PC,which can not be directly used as the real-time processing algorithm.The construction of acoustic logging downhole processing algorithm verification system is an effective way to speed up the development of downhole algorithms and promote the upgrading and improvement of tools.Firstly,based on the analysis of algorithm testing requirements and verification system requirements,the overall design of software and hardware and workflow of the system are proposed.Then,the FPGA minimum system,USB communication module and SRAM interface circuit in the hardware are designed in detail and the PCB circuit board is made.Secondly,software programs such as USB microcontroller and SRAM access module on FPGA,firmware and host computer driver identification module in USB microcontroller,file conversion and file transmission module on host computer are developed to realize two-way fast communication between front-end computer and host computer based on USB module.On this basis,the downhole compression module and host computer decompression module of acoustic logging data based on DPCM algorithm are developed.Finally,the algorithm verification system was tested at three levels : system preliminary,module function and downhole algorithm.The test results show that the function of each module of the system is normal,and the downlink and uplink speeds can reach43.04 MB/s and 34.60 MB/s respectively,which can realize the verification function of the downhole processing algorithm.This work can provide a verification environment for the development of acoustic logging downhole data processing algorithm,and provide a reference for the upgrading and improvement of downhole data processing system in acoustic logging while drilling.