State-of-the-Art Cuttings Transport in Horizontal Wellbores

In the ever-growing use of, directional and horizontal drilling, hole cleaning is a common and costly problem. It can become particularly critical in the case of extended reach drilling where larger and longer wellbores are drilled. During the past two decades, especially in recent years, many laboratory studies as well as field observations have been directed towards addressing the cuttings transport problem. This has resulted in better understanding of the subject and some remedies to the problems. Several correlation/models have also been developed that give the field engineer a tool to better specify the hydraulic requirements in cleaning the hole. However, because of the complexity of the subject, a comprehensive and proven model, which does not exist at this time, requires much more laboratory research and field studies.