Ensuring long-term well integrity and optimum completion performance is important for the economic development of any field. However, as fields are now developed with fewer wells and in more technically challenging environments, new technologies are required to deliver mechanically robust and reliable wells that can be operated at the high rates required to meet today's aggressive production targets. Unfortunately, in this environment, our industry can no longer rely on historical industry practices that are based on generalized principles, aggregate historical data, anecdotal evidence, and simplified analytical models, because the inherent inaccuracy of these types of analyses requires excessive use of a significant safety factor between the planned production rates and the actual deliverability limit of the well.
To address this challenge, ExxonMobil has developed unique, physics-based, completion design and well performance modeling capabilities that are applied during both well planning and production phases to optimize overall well performance.
For example, the ability to accurately model the coupled-physics effects of reservoir compaction, sand production, subsurface shear/slip, completion tubular deformations, and various near-well flow impairment effects enables targeted management of critical mechanical integrity and flow capacity issues. More importantly, these models have provided predictive technologies that have resulted in significant business advantage, as ExxonMobil has developed the capability to quantitatively transform these highly complex issues into well defined, and easily applied "technical limits," which establish the boundaries between conservative, optimum, and potentially detrimental well design and production operations. Practical application has been facilitated by defining these limits in simple terms, including reservoir depletion and/or well drawdown.
The incorporation of advanced physics and the corresponding coupled-physics interactions into modeling, simulation and decision-making processes, enables accurate, definition of well performance technical limits and the ability to produce a well right up to these limits. These physics-based production guidance tools provide the technical basis from well design to choke management, enabling more aggressive production with confidence, without risk of failing or impairing wells unnecessarily.