Well interference in unconventional reservoirs has been a pivotal issue due to its significant impact on well productivity, estimated ultimate recovery, and field development economics. Their detection and quantification of the future production profile of the frac-hit affected well become important to make operational and financial decisions accordingly. Frac-hit detection and production forecasting using a pure physics-based method could be extremely complex, computationally intensive, and significantly demanding in terms of the input information required to create a fit-for-purpose reservoir model. It is desirable to have a robust method to detect if a well has undergone frac-hit and to forecast the resulting production profile, requiring limited and readily available input information. This paper presents a fast, unique, interpretable, and systematic physics-informed data-driven approach to detect well interference events and quantify their resulting impact on future well production. This approach honors the physics of reservoir behavior during transient well-flow, which is represented by a material balance on a closed boundary with expanding control volume, combined with the calculated dynamic drainage volume (DDV) to calculate the average reservoir pressures (Pavg) and well productivity index (PI) profiles as a function of time. This approach requires minimal and routinely available inputs and is computationally robust to scale to the entire field as part of closed-loop reservoir management.
The shale revolution in the US has led to the adoption of multi-staged hydraulic fracturing, allowing for production from ultra-low permeability unconventional reservoirs. However, this practice can result in parent-child interference under tight well spacing, where fracturing one well can negatively impact the productivity of neighboring wells. An existing producer well (parent) can communicate with tightly spaced, newly completed offset wells (children) through fractures (i.e., inter-well, fracture-driven interference, more commonly called as "frac hits") or encroached drainage volumes. This interference can sometimes cause adverse effects, such as damaging production tubing, casing, wellheads, or affect the productivity of the invaded (parent) well.
