Technology Focus: Reservoir Performance and Monitoring (September 2012)
Authors: Vikane Erik 
Published: February 2015

Technology Focus

Positioning for Long-Term High Recovery While Meeting Short-Term Objectives

To balance short-term production and long-term recovery is a key reservoir-engineering challenge in many fields. Optimizing, and even maximizing, short-term production is very important and has high focus in many organizations. The “maximum efficient rate” often is the compromise—a higher short-term, or plateau, rate than this would damage the reservoir irreversibly and a lower ultimate recovery would be the result. The industry has largely succeeded in maximizing short-term production, but case studies seldom demonstrate the link between rates today and ultimate recoveries tomorrow: Discounting makes early accelerated barrels more valuable than later barrels, and because value often is more important than volume (or resource management), the bias tends to be toward high early rates. 

The systematic approach to production optimization, short- and long-term, described in these highlights is worth a closer look. It describes 6 years of experience and improvements.

The key to optimization is data and our ability to transfer data into knowledge. Intelligent-well systems are rich data sources that have expanded over the last 20 years. The systems have improved our intelligent-reservoir-management capabilities such as “intelligent slots,” but there is still unlocked potential. I think development and application of sensors able to read or sense at a distance from the wells will be important, closing the gap between short- and long-term optimization. Just imagine the following situation: You have received information from your intelligent-well sys-tem that a water front is approaching one of your producers and is 500 ft away. What do you do? Do you cut back on this producer because when water breaks through, you do not have sufficient water-handling capacity to obtain a high cumulative recovery from this well, or do you crank the well up and force water breakthrough because this is the first producer with water breakthrough and there is a lot of spare water-handling capacity allowing you to produce the well at high water cut longer, securing a good ultimate recovery?

Understanding reservoir performance is about data, knowledge, experience, and feedback loops. It is also about our ability to do the right thing at the right time. One of the selected papers deals with transformation and change in the exploration/production business, why they are needed, and potential solutions to identified challenges. This paper made me reflect on my own organization and how we go about balancing short-term production with long-term recovery—sometimes without acquiring new (feedback) data from the reservoir.

Recommended additional reading at OnePetro: www.onepetro.org.

SPE 153220 Hybrid Forecasting Methods for Multifractured Horizontal Wells: EUR Sensitivities by M. Nobakht, SPE, Fekete Associates, et al.

SPE 150868 Improved Determination of Well Rate From Temperature and Pressure Distributions Along the Well by E. Barrett, SPE, Santos, et al.

SPE 151807 The Extinction of Skin by M.T. Byrne, Senergy, et al.

SPE 147059 Unconventional Type Curves: Useful, or Sirens of Destruction? by William J. Haskett, Decision Strategies