Production engineers are facing a new challenge when trying to select optimal well-production systems (in particular artificial lift) for important, relatively new resources: liquids-rich shale and deepwater subsalt applications. They are being asked to make such a selection when there are still large uncertainties about the well productivity and the produced-fluids thermodynamics (i.e., unclear functional requirements).
These applications are overall quite different, and the reasons for the large uncertainties are not the same. On the other hand, both applications involve relatively deep wells and relatively high pressures and temperatures downhole and the associated complications. For both applications, one needs to try to select a system that is flexible, so that it can work properly in a relatively wide range of operating conditions; that is reliable, so that it does not require frequent interventions; and that is easily retrievable, so that there is no need to have an intervention with a full-size rig every time you have to replace a key part of the system. By the way, space is limited both in the casing downhole and in the tubing hanger (for extra penetrations); therefore, there is only so much you can install in the well to try to achieve all this.
The recent increased cost and decreased availability of high-capacity rigs have certainly provided extra incentive for the development of rigless deployment and intervention techniques. Nevertheless, further technology development is still required to make available production and intervention systems that meet the demands of these applications.
Meanwhile, what is a production engineer to do? The best approach will depend on the business drivers for the operator, in particular the right balance between short- and long-term goals. Some solutions may require a lower capital investment or allow for higher production rates initially but at the cost of a lower overall recovery from the reservoir in the long term. If the focus is on long-term reservoir recovery, the best approach likely will involve a higher capital investment and lower production rates (and lower drawdowns), at least initially.
This Month's Technical Papers
Optimized Well Modeling of Liquids-Rich Shale Reservoirs
Improved Recovery Rate in Subsea Wells by Use of Riserless Light Well Intervention
Riglessly Restoring the Functionality of Subsurface Safety Valves
Recommended Additional Reading
SPE 166177 Completion and Production Strategies for Liquids-Rich Wells in Ultralow-Permeability Reservoirs by Amit Kumar, Halliburton, et al.
SPE 166027 Decision Analysis of Long-Term and Short-Term Production Optimization Applied to the Voador by Agus Hasan, Norwegian University of Science and Technology, et al.
SPE 166379 A Case History: The Installation of a System To Restore Full Safety-Valve Functionality to a Malaysia Offshore Well With a Damaged Control Line by M.K.M. Aminuddin, Petronas, et al.
Francisco J.S. Alhanati, SPE, is the managing director for C-FER Technologies in Edmonton, Alberta, Canada. He holds a PhD degree in petroleum engineering from The University of Tulsa. Alhanati has spent most of his 30-year career in the industry on applied research and development related to production operations, first with Petrobras in Brazil and, more recently, with C-FER in Canada. He received the 2013 SPE Production and Operations international award. Alhanati has served SPE as a section officer, a member of the Well Operations Committee for the Annual Technical Conference and Exhibition, a Distinguished Lecturer, an author for the SPE Petroleum Engineering Handbook, a Technical Reviewer for SPE journals, a member of the JPT Editorial Committee, and a member of the Production and Operations Advisory Committee.