Research status and development trend of near-bit MWD in underground coal mine

Near-bit meusurement while drilling (MWD) integrates several key technologies such as near-bit multi-parameter measurement, power supply and communication across positive displacement motor drills, turbine continuous power generation and high-speed mud pulse wireless transmission, capable of obtaining various types of parameters near the bit. It is one of the key components of intelligent drilling technology in underground coal mine. Herein, the limitation of the existing technology applied in coal mine was analyzed with full reference to the development experience and development path of near-bit MWD in the field of surface oil and gas drilling. Meanwhile, the research idea of near-bit MWD technology in underground coal mine was proposed based on the current MWD technology in coal mine. Besides, the research status of near-bit MWD in underground coal mine was discussed, focusing on solving the technical challenges for structure miniaturization, instrument unitization, explosion-proof modularization, measurement collaboration and control integration. Under the background of intelligent construction of coal mine, it was proposed to vigorously promote the integrated development of near-bit MWD in underground coal mine with next-generation information technologies such as 5G communication, big data, cloud computing and the Internet of Things in future, from the aspects of near-bit multiple paraeters integration measurement, near-bit parameter dynamic monitoring, near-bit rotary steerable drilling and near-bit adaptive drilling.