Application of Multi-Segment Arps Hyperbolic Decline Model Based on Identified Flow Regimes in Unconventional Wells
Abstract
Unconventional reservoirs, specifically volatile oil shale plays, behave with much more complexity than conventional reservoirs and cannot be modeled consistently and accurately with Arps methods. An adaptation of the Arps method has been suggested as a viable method to accurately model the decline of a volatile oil shale well. This method applies the Arps hyperbolic decline model using multiple segments across the life of the well based on distinct flow regimes identified in the well’s production history. Modeling multiple segments based on flow regimes observed in production data adds a degree of ingenuity and robustness to the widely accepted traditional Arps model. The objective of this research project is to learn how to effectively apply multi-segment Arps hyperbolic decline models to horizontal, multi-fractured volatile oil wells in the Permian Basin. The Multi-Segment Hyperbolic Decline Model is a viable method in forecasting the decline of unconventional wells.
The transient nature of ultra-low permeability shale reservoirs indicates a more complex decline profile than can be modeled successfully using the modified Arps model. Typical volatile oil shale wells are characterized by steep initial declines that gradually level off as the well transitions from transient linear flow to boundary dominated flow. The resulting decline profile segmented by distinct flow regimes results in an estimated ultimate recovery that is greater than that of the modified Arps model, suggesting the Arps model is underestimating reserves when compared to the multi-segment method.
Citation
Sherman, Byron Casey (2019). Application of Multi-Segment Arps Hyperbolic Decline Model Based on Identified Flow Regimes in Unconventional Wells. Master's thesis, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /188797.