2006 年 71 巻 5 号 p. 436-444
Cuttings transport is one of the biggest challenges in extended reach drilling(ERD). However, few simulation tools satisfy the industry requirement for more practical and comprehensive study on cuttings transport in ERD. The problem might lie in the situation that most conventional cuttings transport models or simulators are of steady state calculations obtaining critical flow rate for a single section of the whole well. In this study, our previously developed prototype simulator of transient cuttings transport using two-layer model formulation was modifi ed and improved for more practical use. Modifi cations of the simulator include(1) setup for simulation input of precise well profile based on the directional survey data,(2) consideration of moving bottomhole boundary with increases of drilling depth as time elapsed,(3) a simple model for effects of drillpipe rotation. To evaluate functionality and potential of the modified simulator, some post analyses on cuttings transport were carried out for an extended reach well drilled in the Sarukawa Oil Field. The simulator successfully demonstrated transient behaviours of cuttings bed height and annular pressure over the whole well trajectory.