Abstract
Extensive literature has been published concerning Fracture Driven Interactions (FDIs). Many of these works describe FDI anatomy, physics and impact on existing wells including the success or failure of various mitigation techniques. In this paper, time synchronized FDI surface pressure data from existing offsetting wells is used to study fracture wing growth. This includes timing, fracture half-length estimation and observing the movement of injected fluid sequentially from well-to-well during fracturing operations.
In 2019, an in-fill Eagle Ford well development consisting of two newly drilled wells and seven offsetting existing wells was performed. The new wells were located such that each treatment well was bounded on both sides by existing wells. Further, there were first order wells (closest well to treatment well) and second order wells (next well over from the first order well) bounding one of the treatment wells and FDIs generated pressure communication were seen in both the first order well and the second order well. Six of the existing wells were preloaded. This was done to test the efficacy of preloading to protect the existing wells from FDI damage.
The workflow was organized into first deriving detailed data from all FDIs that occurred in individually monitored wells. This was followed by examining well pairs bounding the two treatment wells to study fracture wing development in each stage. Lastly, first order and second order wells that had sequential FDIs from the treatment wells were examined to study fluid volumes and timing between wells as well as FDI magnitude dampening in second order wells. All monitored wells were left shut-in during the completion operations. The wireless surface pressure monitoring sensors were time-synchronized to internet time and the data was viewed in real-time.
The authors’ found that preloading dampened FDIs but did not completely stop them. The degree of the success of preloading was graded by determining a reduction of recovery time (if any) and how well production rates were protected. At the time of this writing, flowback operations are ongoing and one primary well recovered to pre-frac rates within one week. We anticipate a corresponding reduction of recovery time in the other wells.
This paper presents methods and processes that offer a solution to identify candidate stages for FDI mitigation and potential optimization of project economics. The time synchronization with internet time eliminated all uncertainty with regards to timing. As will be shown, for this type of study, there cannot be uncertainty with timing. No inconsistencies in timing were found. It was also determined that FDI data must be viewable in real-time for it to be used to make on-the-fly mitigation decisions. In this project, a "passive well defense" technique was utilized; preload but take no other actions.
