The Key Technologies of High Precision Imaging Logging while Drilling

In order to solve the problem of the long distances between the geosteering while drilling system and the drill bit, and the problem of limited detection information and low detection accuracy, a near-bit gamma imaging logger and a high-resolution resistivity LWD tool were developed. They are based on the principle of sector scanning while drilling, which combines with a MEMS dynamic tool surface detection, imaging acquisition algorithm of near-bit gamma rotation cumulative counting, and the imaging acquisition algorithm driven by the dynamic PID adjustment emission of resistivity while drilling. It takes into consideration the fact that the near-bit gamma measurement covers 16 sectors and resistivity while drilling measurement contains 128 sectors. The results of field test suggest that the near-bit gamma imaging LWD data can provide technical support in the geosteering drilling of complex oil and gas reservoirs, while the resistivity LWD data is consistent with the cable logging data and can provide valid data for formation evaluation while drilling. Studies show that the near-bit gamma imaging logger and the high-precision resistivity LWD logger can acquire very large quantities of high precision logging data, and provide support in geosteering and formation evaluation.