Drilling and Production Waste Injection in Subsea Operations – Challenges and Recommendations

Abou-Sayed, A.S., and Guo, Q.
Presented at 2002 Offshore Technology Conference held in Houston, Texas U.S.A., 6–9 May 2002.


Handling drilling and production waste associated with oily contaminated drill cuttings, NORM and produced water is an environmental and economic issue in offshore drilling and production operations. There are a number of waste management options and subsea injection into suitable geological formations can be a preferred one. This is because it can achieve zero discharge operations; eliminating transportation and spill risks. It can also be economically favorable. Although subsea drill cuttings and produced water re-injection operations have been conducted in an environmentally acceptable manner, system design and operational experience are limited. A few worldwide drill cuttings re-injection operations from mobile offshore drilling units are reviewed first in the paper. Lessons learned from these and other system design and operational experience include a detailed subsurface study and careful engineering, wellhead and injection system design and effective communication to handle emergency disconnect, quality control on well integrity and slurry injection procedure. Challenges and best practice guidelines for waste injection operations from subsea wellheads are given to minimize failure and maximize success.