随钻声波测井研究进展

论述了随钻声波测井的纵波测量、横波测量及仪器的发展,分析了随钻声波测井面临的难题.随钻纵波测井仪器隔声体是实现随钻纵波测量的关键;利用漏能纵波求取极慢地层的纵波速度的方法也有所发展.埘随钻横波测井进行r总结.快地层随钻横波测井除了可以采用单极子测量,还可以采用四极子模式进行测量;慢地层随钻横波测井可以有偶极子或四极子等方式进行测量,存在争议的是慢地层随钻偶极子的横波测量足否可行.对仪器偏心的研究表明从随钻偶极子中提取地层横波足有可能的.随钻声波测井由于偏心的原因无论采用何种模式进行测量都会产生频散.总结了随钻测井噪声的研究现状,表明噪声均为低频噪声,埘随钻横波测井有一定影响.

Review on the Development of Sonic Logging While Drilling

Introduced is the status about sonic LWD including compressional wave measurement, shear wave measurement and sonic LWD tool, and analysed are difficulties in real sonic LWD. Acoustic isolator is the key to LWD compressional wave measurement. Some progresses have also been made in the method of estimating the slowness of P wave in very slow formation from leaky-P wave in recent years. Then summarized are the progresses about the LWD shear wave measure-ment. The LWD shear wave measurement in fast formation can be realized by monopole mode and quadrapole mode; in the slow formation, both dipole mode and quadrapole mode are optional. However,the feasibility of estimating the shear slowness in dipole mode is controversial, which has confirmed the possibility in the wave propagation studies on acoustic logging while drilling eccentric tool. There is dispersion for the off-centered tool regardless of the source type. The research documents about noise in real sonic LWD indicate the noise spreads to cover the low frequency domain, which is the shear wave measurement frequency domain. It will influence the shear wave measurement inevitably.