钻井液压力脉宽及脉位多进制相移键控信号分析  

Analysis of drilling fluid pressure MPSK signals for PWM and PPM

作　　者：李翠[1] 高德利[1] 沈跃 

机构地区：[1]中国石油大学石油工程教育部重点实验室,北京102249 [2]中国石油大学理学院,山东青岛266580

出　　处：《石油学报》2013年第1期178-183,共6页Acta Petrolei Sinica

基　　金：国家自然科学基金创新研究群体项目(No.51221003);国家重大科技专项"复杂结构井优化设计与控制关键技术"(2011ZX05009-005)资助

摘　　要：在构建出钻井液压力脉宽及脉位多进制相移键控(MPSK)调制信号数学模型的基础上,分析了MPSK信号的频谱特性,从频域研究了将脉宽及脉位调制方式应用于钻井液压力MPSK信号传输的可行性。通过建立MPSK信号沿定向井钻柱分布的传递函数,研究了钻井液信道参数和调制方式对信号传输的影响。数值分析表明,钻井液压力脉宽MPSK调制信号的频谱主瓣带宽内信号的相对能量过低,从频谱角度看不适于频带传输;钻井液压力脉位MPSK调制可用于井下数据的频带方式传输,但信号的传输损失相对较大,因此对信号的检测、处理及旋转阀的转速控制要求较高。Signal frequency spectra were analyzed based on establishing a mathematic model for multiple phase shift keying （MPSK） signals for pulse width modulation （PWM） and pulse position modulation （PPM） of drilling fluid pressure. The feasibility of apply- ing the PWM and PPM methods to transmit down-hole MPSK signals of drilling fluid pressure was studied in terms of frequency do- main. Impacts of drilling fluid channel parameters and modulation methods on data transmission were examined by establishing trans fer functions for the MPSK signal distribution along directional drill string. Numerical calculation results show that the relative ener- gy of signals within the main-lobe bandwidth of MPSK signal for PWM of drilling fluid pressure is too low to fit the frequency-band transmission in terms of frequency spectra, while only the MPSK signal for PPM of drilling fluid pressure can be used for data fre quency-band transmission. However, this transmission pattern usually has relatively stricter requirements for the signal detection, treatment and rotating speed control of the rotary valve because of a greater transmission loss.

关 键 词：随钻测量 载波调制 多进制相移键控 脉宽调制 脉位调制 传递函数 

分 类 号：TE249[石油与天然气工程—油气井工程]