Activity in the Barnett shale of North Texas has continued to surge over the past several years, and with this surge in activity has come a steady evolution of completion techniques. Most operators agree that the best Barnett shale wells are those that have the largest fracture network development. One of the biggest challenges facing operators today is determining which completion techniques create the largest fracture network and the most effective diagnostic methods for evaluating these techniques in order to continue the optimization process. Numerous operators have used diagnostic techniques to optimize well placement and overall completion design. Approximately 20% of the Barnett shale completions have used radioactive tracers or chemical tracers to determine proppant placement, cement integrity, lateral cleanup, and offset well interference.
Many operators are drilling parallel horizontals as close as 500’ apart. Simultaneous fracturing operations on these close offsets have also been used successfully in many areas. In general these techniques are being used to maximize fracture network development while possibly minimizing the number of surface locations. Additionally, with over 5000 available existing well-bores, re-fracture stimulations have become a significant piece in the evolution process.
This presentation will cover several Barnett Shale close offset and re-frac projects. The main discussion will deal with Spectral gamma ray logging results and chemical tracer results and how they were used to explain well performance anomalies. Additionally, we will utilize the sampling of chemical tracers to develop well-to-well interference profiles and help quantify communication between fracturing stages.