The study objective was to empirically determine a completion design that would best improve fracture cluster effectiveness and optimize Stimulated Rock Volume (SRV). Field trials and analyses were performed on a Montney Formation pad to understand the impact of completion design factors such as completion fluid viscosity, cluster spacing and proppant concentration ramp on cluster efficiency and fracture geometry. Technology utilized included a permanent fiber optic cable and wellbore acoustic imaging for near field measurements. Pressure based hydraulic fracture mapping in addition to microseismic and the permanent fiber measurements of cross well strain were used for far field measurements. Near field diagnostics were correlated to far field diagnostics to create a fulsome interpretation and understanding of the results.
An infill occupation of ten Montney wells with three separate landing zones was selected for the study. A well drilled in the middle of the pad was chosen to test four different completion designs along the lateral, alternating from a base design to tighter cluster spacing (high intensity), slower proppant concentration ramp (slow sand ramp) and increased completion fluid viscosity (High Viscosity Friction Reducer - HVFR). Permanent fiber optic cable, microseismic and acoustic imaging were deployed on this well to measure the near field impact between the various completion designs. The nearest two wells also had acoustic images taken. Far field measurements of the surrounding six wells were taken using microseismic or pressure based hydraulic fracture mapping. The collected data was plotted and analyzed to understand the impact of completion design on cluster efficiency and fracture geometry.
Through diagnostic analysis it was determined that some completion design variables had an impact on near field and far field fracture geometry. Altering the completion design resulted in a measurable difference in perforation erosion signatures. Where four different completion designs were tested along the wellbore lateral, the HVFR test showed decreased cluster uniformity. HVFR fractures with low pump rates closed early relative to slickwater fractures. Slickwater designs with the highest cluster efficiency and cluster uniformity resulted in the most constrained fracture geometries versus other designs.
Understanding and applying the conclusions from this study will support operator decisions on completion design to optimize cluster efficiency and fracture geometry. Optimized fracture geometry improves well productivity and overall project economics.
