Breaking Through the Boundary: Are HVFR and Landing Target The Solution? A Charlie Lake Exploitation Strategy

Abstract

The objective of this exploitation strategy was to evaluate fracture-driven interactions (FDI) between intervals within the Braeburn members of the Lower Charlie Lake formation. With the primary goal to determine if a single well can be drilled in the Middle Braeburn and effectively drain reserves from two previously distinct producing intervals. The target intervals in this study were separated by a boundary layer composed of interbedded anhydrite, siltstone, and dolomite layers.Wells were completed in sequence using cemented ball-drop fracturing, and high-viscosity friction reducer (HVFR) fluid systems. Diagnostics including pressure monitoring, fracture modelling, and tracers were employed to evaluate stimulation response between wells. Realtime downhole pressure monitors observed the non-producing upper wellbore, while the lower well produced. Fluid rheology determined viscosity changes for different HVFR loadings, and fracture modelling assessed the impact of anhydrite on fracture height at different fluid viscosities. Proppant tracers injected in the lower well were logged in both wellbores observing propped communication between layers. Fluid and pressure diagnostics were used to monitor effective drainage between wells over time.During completion of the lower well, two (2) notable pressure communication events were observed in the offsetting upper well. Following the logging applications performed on both wellbores the results displayed three (3) localized points along the offsetting lateral. At which, a propped communication event was observed within a one (1) meter radius of investigation from the offsetting wellbore. The heel-most propped communication event in the offsetting wellbore was correlated to one of two (2) observed pressure communication events. The two (2) other instances of propped communication did not correspond with an observed pressure event. Following the logging application, the lower well was flowed back and put onto production. During this production period, the upper well remained shut in. Subsequent fluid diagnostic responses have indicated an increasing FDI response, facilitating the flow of hydrocarbon from the upper to the lower wellbore. This communication was primarily observed near the heel of both wellbores. Based on the results of the diagnostic tracers, the fracture model was updated to provide a development tool that would be more predictive for fracture height growth around thin anhydrites in the Charlie Lake formation.The technique of fracture stimulation through the anhydrite layer can be used to reduce the total number of wells required to effectively drain the formation.