随钻方位成像测井数据压缩与还原方法

Compression and Restoration of While-Drilling Azimuth Imaging Logging Data

在地质导向施工中,随钻数据实时上传是保障导向精准的关键。目前受限于MWD传输速度,随钻成像测井数据难以实时传输到地面,影响导向过程中地层特征的实时获取,制约导向实施效果。对此,提出了一种随钻成像测井数据高效压缩与还原方法,利用随钻方位成像在层界面位置成等值线特征,建立等高线方程;采用函数映射关系代替图像数据,通过传输函数关系所对应的图像映射关系参数大大降低数据量,再通过反函数解压,获取高质量成像图像,减轻泥浆脉冲数据传输带宽限制的压力。该技术试验结果表明,对井下随钻方位伽马测量数据压缩率达92.9%,大大减少了地质导向时井底数据实时上传量,实现了随钻成像数据的实时上传,可为岩性、层界面等地层关键信息实时解释提供数据支撑,助力精准地质导向。

In geosteering process,real-time uploading of drilling data is the key to ensuring precise geosteering.Currently,due to the limited MWD transmission speed,it is difficult to transmit real-time imaging logging data to the surface,which affects the real-time acquisition of formation characteristics during the geosteering process and restricts the implementation effect of geosteering.A highly efficient compression and restoration method for while-drilling imaging logging data was proposed to address this issue.Firstly,the contour line equation was established by using the geometric features of the penetration position of while-drilling azimuth gamma imaging.Then,to use function mapping relationship replaces image data,by which the data volume is greatly reduced.Finally,to use inverse function decompress the data to obtain high-quality images.The application results of this technology show that the compression rate of downhole while-drilling azimuth gamma logging data reaches 92.9%,greatly reducing the real-time uploading volume of bottomhole data during geosteering,achieving real-time uploading of imaging data while drilling,and providing data support for real-time interpretation of key formation information such as lithology and layer interfaces,assisting in precise geosteering.