Cuttings Bed Erosion in Horizontal Wells

Abstract

Many of the time consuming and economically demanding drilling problems faced today can be tracked back to poor hole cleaning, even more so when drilling through highly inclined sections. Improved hole cleaning operations can subsequently guarantee improved well construction quality.

Hole cleaning has been subjected to comprehensive investigation, where rules of thumb have been proposed to ensure acceptable levels of cuttings transport to surface. Nonetheless, the superiority of oil based muds over water based muds is still not fully understood.

To try and unveil the ambiguities within the topic, this thesis focuses on the erosion threshold of cuttings beds where a simple model and laboratory experiments methodology to be followed are proposed. Instead of the standard approach taken to this date in the petroleum engineering field, where most of the efforts are directed into the drilling fluids features, here we follow the sedimentology s approach, where both drilling fluid and cuttings bed composition are thoroughly reviewed.