用光纤电缆传输信号的多种频率阵列声波测井

Multi-frequency Array Acoustic Logging With Fiber Optic Cable Transmitting Signal

介绍了光纤电缆传输系统传输速率为10Mbit/s的多频率阵列声波测井仪及实际测井案例。多种频率阵列声波测井仪器的声系能在井下发射频率为10、204、0kHz等3种声波信号,用2组各有8个接收探头组成的接收阵列。用3种频率的探头进行的井下声学性质测量,可以获得在井壁附近不同径向深度处的介质的声学性质的测量记录结果。用长度为4250m的光缆及相应的井下电-光转换系统(井下光端机),井下光电马笼头,地面绞车上的光电转换滑环(光电滑环)和地面的光-电转换系统(地面光端机),已经能保证所传输信号的损失在10dB以下,目前已经能以1.25Mbit/s的速率传输井下采集的3种频率的声波波列信号,并已在辽河油田的模拟井内成功地进行了现场实验。

Multi-frequency array acoustic logging apparatus with fiber optic cable transmission system, which transmits signal at a speed of 10 Mbit/s, and it＇s practical logging case are introduced in this paper. The acoustic sonde of the multi-frequency array acoustic logging apparatus can transmit three acoustic signals in the borehole, whose frequencies are 10, 20 and 40 kHz. There are two sets of receiving arrays, each of which has eight receiving transducers. The measurement of the borehole acoustic property with three frequency transducers can obtain the measurement result of the medium＇s acoustic property in different radial depths round the borehole wall. The fiber optic cable whose length is 4 250 m and corresponding borehole electricity-light converting system （borehole optical transmitter and receiver）, borehole light and electricity halter, light and electricity transformation collector ring on the ground winch （light and electricity collector ring） and ground light and electricity converting system （ground optical transmitter and receiver） can control the damage of the transmitted signal under 10 dB. Now, it already can transmit acoustic wave train signals of three frequencies which are collected in the borehole at a speed of 1.25 Mbit/s, and the field log experiments have been made in the simulation well of Liaohe oilfield successfully.