Sanding: A Rigorous Examination of the Interplay Between Drawdown, Depletion, Startup Frequency, and Water Cut

摘要

Factors and mechanisms leading to sanding are described within an integrated-rock and soil-mechanics framework. While the conventional sanding models generally consider a single mechanism for sanding, namely the critical depletion resulting in rock disag-gregation, the proposed approach considers the interplay of several mechanisms that can lead to the rock breakup and sand transport. One important difference is that rock disaggregation is not seen to represent the onset of sanding, because the sand mass can offer significant resistance from frictional properties, interlocking of sand grains, and arching. The approach presented here can be used to explain why sanding in the field tends to be episodic, and how depletion, which is a major factor in rock breakup, can be highly effective in holding broken-up sand grains together and, in fact, become a sand-stabilizing agent. The proposed approach is used in discussing sanding at several wells in two different fields. These wells have been in production for several years and show that sanding cannot be linked to just one unique mechanism (e.g., depletion). However, once all mechanisms for sanding are incorporated, a more consistent analysis can be used by completion and production engineers to make more objective and pragmatic decisions in managing sanding while maximizing production over the life of the well.