Date(s) - 09/17/2019
11:30 am - 1:00 pm
Depletion Effects of Parent Well Production Over Time and Impact on Well Spacing in the Wolfcamp, Delaware Basin
Cyrille Defeu, Region Technology Domain Manager OneStim, Schlumberger
Parent-child relationship is becoming a topic of high interest in the Permian Basin as more infill wells are being drilled at various times after the parent well has been produced. As the parent well is being produced, constant well spacing based on virgin condition becomes problematic because pressure depletion around the well leads to change in stress magnitude and orientations. This continuous change in reservoir conditions, is critical for planning infill well. Negative effects of parent well depletion include:
-Asymmetric fracture propagation from the child well into the depleted area around the parent well
-Potential detrimental fracturing hits to the parent well
These effects would potentially impair the production performance of both parent and infill wells, further reducing the overall pad efficiency of the pad completions.
This study uses an advanced modelling workflow to determine the impact of parent depletion on infill well spacing at various periods of the parent well production. Parent well behavior is simulated using an unconventional fracture model (UFM), and the model is calibrated with available treating data. The resulting hydraulic fracture uses an advanced unstructured gridding algorithm that accounts for a fine complex fracture network along the lateral. A high-resolution, numerical reservoir simulator that combines the unstructured grid, rock physics, and reservoir fluid data is then used to match historical production data. The reservoir pressure depletion profile at various time steps (6, 12, 24, and 36 months) is used as an input to calculate the resulting stress field state via a finite element model. The resulting updated geomechanical properties are used to simulate the infill well hydraulic fracture geometries at various spacing; subsequent unstructured grids are created and used to forecast production. Results are then compared to quantify effects of depletion and help optimize infill well spacing to mitigate parent depletion impact.
Cyrille Defeu is OneStim Technology Domain Manger for the Permian basin at Schlumberger. Cyrille currently works with the Technology Integration Group in OneStim where he helps optimize production in various basins by leveraging technology, software and data integration. His focus includes maximizing pad production and infill wells optimization in depleted environment. His oil and gas career started in 2011 in North Dakota as field engineer, where he supported operations and field implementation of new stimulation technologies in Williston Basin before joining the Technology Integration Group in 2013 as a Production and Stimulation Engineer. Cyrille earned his B.S. degree in Chemistry from University of Buea, B.S. and M.S. degrees in Petroleum Engineering from Texas Tech University.