Dan Gunderson, BJ Services Company, USA, Mark Yamasaki, Performance Sciences Inc., King Anderson, Isotag Technologies, Inc.
Historically, maximizing completion and stimulation effectiveness in wells with multiple productive zones was hampered by lack of robust data. It is now possible to assess early-time zone-by-zone stimulation effectiveness (apparent fracture half-length) and reservoir quality (effective permeability-thickness) without the need, cost or risk of in-well operations, such as a spinner survey. This is accomplished by employing a series of molecular markers in each stimulation stage, which can be quantitatively analyzed over a sustained period of time. When used with the subsequent commingled total well production and the fracture closure flow periods, a pressure transient drawdown analysis provides the necessary descriptive knowledge. In many cases, additional information can also be gleaned regarding zone-by-zone free water contribution. Example stimulation results will show the effectiveness of this procedure. The paper will demonstrate the effectiveness of this technique and the value operators garner from it.