Optimal drill string design for acoustic borehole communication
The acoustic telemetry used the drill string as a communication channel, which allows data transfer without interrupting drilling operations. This technology suffers from stop-bands that reduce the feasible bands for transmission up to 60 percent. The stop bands come due to the structure of the drill string constructed from pipes and tool joints. In this paper, we optimized the design of the drill string main components, which are pipes and tool-joints lengths, with an aim to increase the pass-bands total bandwidth. Using the verified drill string channel model, we proved that, with optimal lengths of pipes and tool joints, we can make the whole drill string channel bandwidth available for transmission. We also investigated the effect of small deviation from the optimal lengths on the channel transmission bands. The results showed that an increase of more than 138 percent in the available transmission bandwidths compared with standard drill string dimensions.