Horizontal wells in unconventional reservoirs exhibit steep decline rates yielding low recovery factors. Enhanced Oil Recovery (EOR) in tight oil reservoirs has received industry-wide attention to improve recovery factor per lease unit. Historically, a few operators in Eagle Ford and Bakken have implemented EOR pilots primarily utilizing gas Huff-n-Puff (HnP) method.

The key objectives of this study were 1) to improve reservoir characterization through history matching of a fully integrated high-resolution reservoir model, while incorporating all the parent/infill and the refractured wells, and 2) to analyze and design HnP strategies that yield the best EOR performance.

Key learnings include the impacts of well placement, completions, prior depletion, and well-to-well interference on predicted HnP performance. We introduce a framework that emphasizes the significance of three key factors, which we refer to as the "3C's of HnP". These three factors are defined as Connectivity, Contact, and Containment. By considering these key factors in the HnP design, operators may significantly increase their chances of achieving successful EOR implementations.

 Speaker - Caner Karacaer, NITEC LLC; with input from Damon Bennett, Devon Energy