摘要
针对Ⅱ界面窜槽的井孔声场传播机理不清,以及缺乏有效的Ⅱ界面固井质量评价办法的问题,提出采用实轴积分法模拟Ⅱ界面窜槽井孔声场的全波列曲线、二维谱和频散曲线,提取Ⅱ界面特征波,分析窜槽流体环厚度、振源主频、套管尺寸等因素对Ⅱ界面特征波的影响。结果显示:当流体环厚度比较小时,特征波首波幅度随厚度增大而减小;反之,首波幅度随厚度增大而增大;随厚度增大首波旅行时间近似线性地减小。使用特征波幅度计算Ⅱ界面水泥胶结指数,可以消除仪器主频和套管尺寸的影响。进而认为特征波主要是在钢套管和水泥环中传播,通过对比发现决定特征波幅度及旅行时间的主要是水泥环厚度,而非窜槽流体环的厚度。
Because propagation mechanism of borehole acoustic field with Ⅱ interface channeling was unclear and lacked of effective Ⅱ interface cementing quality evaluation methods. Real-axis integration method is used to simulate the full wave curve, the two-dimensional spectra and dispersion curves of borehole acoustic field with Ⅱ interface channeling. Ⅱ interface characteristic wave is extracted and analyzed the influence factors to Ⅱ interface characteristic wave which included channeling fluid ring thickness, local oscillator frequency and tube size et al. The results show： when the fluid ring thickness was relatively small, the first wave amplitude of Ⅱ interface charac- teristic wave decreased with increasing thickness On the contrary, the first wave amplitude increased with the thick- ness; the first wave travel time analogously decreased with increasing thickness. Characteristic wave amplitude is used to calculate the cement Bond index, and can eliminate the effects of local oscillator frequency and tube size. Account that characteristic wave mainly spread in steel casing and cement. And discovery by comparison that the most important factor of the characteristic wave amplitude and travel time were cement thickness instead of channe- ling the fluid ring thickness.
出处
《科学技术与工程》
北大核心
2014年第35期27-33,共7页
Science Technology and Engineering
关键词
Ⅱ界面
特征波
井孔声场
窜槽厚度
固井质量
Ⅱ interface characteristic wave borehole acoustic field menting quality channeling thickness ce-
