Abstract
This paper highlights the value of post-fracture tracer analysis as an evaluation tool to aid in fracture design. A fracture design can be evaluated and compared to actual field results. When the results of this fracture design analysis are then compared to tracer analysis and to predicted and actual deliverability, fracture design can be improved and optimized. To verify this procedure, five wells were chosen for a case study.
The chosen gas storage reservoir had two active pay zones separated by 14-30 ft. Radioactive tracers were run in the treatments of five gas storage wells. Wells were then logged to determine the location of the tracers and determine whether both zones were effectively stimulated. In addition to determining whether zones were effectively stimulated, determining fracture height and comparing measured to the design fracture height was possible.
All of the wells were flow tested before stimulation, and potential deliverability increase was predicted. Post-stimulation flow potential was estimated by the choke flowback results and compared to predicted results. (Multi-point flow tests will be conducted after one year of storage activity to determine actual results.) Flowback results indicate good correlation between fracture design predictions and actual field results.
