声波钻杆信道及信息传输仿真研究  

On Simulation of Acoustic Drill String Channel and Information Transmission

作　　者：尚海燕[1] 周静[1] 燕并男[1] 

机构地区：[1]油气钻井技术国家工程实验室西安石油大学井下测控研究室,陕西西安710065

出　　处：《测井技术》2015年第2期165-170,共6页Well Logging Technology

基　　金：国家科技重大专项大型油田及煤层气开发项目旋转导向及随钻测录;酸性气层测试技术与装备(2011ZX05021-005);中国石油天然气集团公司重大专项钻井新装备新工具研制课题随钻测量与传输装备研制(2014B-4313);陕西省教育厅自然科学研究项目随钻声波传输信道模拟与信息最佳传输研究;西安石油大学科技基金研究项目OFDM技术在随钻声波遥传系统中的应用研究

摘　　要：为利用声波沿钻杆有效地随钻传输钻井数据,提出应用声波无缝传输模型将任意井下钻具组合(BHA)分解为单个声波无缝传输模型(RATO)的级联。建立了BHA中每个钻具的RATO,分别设计FIR滤波器模拟该模型,根据对信道通带位置最佳逼近原则应用相位均方误差最小准则获得最佳FIR长度;将子双口网络参数连乘得到模拟的多钻具级联构成的BHA的系统函数;应用有加工误差为±4%的5in同规格钻杆随机级联为例仿真声波钻柱信道验证了FIR滤波器的方法的正确性和可行性;在该信道上采用2FSK调制解调方式进行信息传输仿真,信号载频位于信道子通带内,约2 500m信道、传输波特率为20bit/s时误码率小于3%。可以应用FIR滤波器仿真声波钻柱信道进行信息传输研究,为随钻声波传输仪器的研制提供测试平台和技术支持。In order to develop a communication system that uses extensional stress waves in hollow steel drill pipe to carry encoded data between the bottom of well and the operator, the reflectionless acoustic transmission models（RATO） are established, with which the calculation of the acoustic properties of bottom hole assembly（BHA） could be decomposed into the cascade of the RATO of single drill pipe owing to no reflection at the position of models connection. Then a finite impulse response（FIR） filter is designed to approach parameter of two ports network of the RATO of single drill pipe, phase approximation criterion is applied to determine the optimal FIR length. Next, by multiplying two port network parameter of all single ones, the two port parameter of the whole BHA can be calculated quickly and easily. Finally, citing cascaded 5 inch standard drill pipes with machining error within ±4% as an example, FIR filter is designed to simulate this about 2 500 meters channel. The results show the practicality and reliability of the FIR channel simulator. Furthermore, 2FSK modulate and demodulate is used in this FIR channel to transmit information of drilling. When the carry frequency of 2FSK is within the pass bands of the acoustic channel, the baud rate reaches 20 bit/s with the bit error rate lower than 3%. Therefore, FIR method could he applied for simulating acoustic channel transmission characteristics of various BHA and information transmission methods can be studied on various simulating channel, thus providing an effective testing platform for the development of acoustic instruments.

关 键 词：随钻声波测井 钻杆信道 声波无缝传输模型(RATO) 脉冲滤波器(FIR) 双口网络 钻具组合(BHA) 

分 类 号：P631.84[天文地球—地质矿产勘探]