Abstract
Field development relies on understanding geological changes across a shale asset, adopting a successful landing zone strategy, and optimizing completion designs specific to each landing zone. Different areas may require different landing zone strategies or completion designs as a function of lithological and geological changes across the asset. Depletion effects also impact optimal landing and completion designs among pads. Therefore, a comprehensive field development plan is needed to address uncertainties and challenges that are associated with shale well development.
In this study, a simulation model is calibrated against field data, and then used for field development optimization. The plan first screens a wide range of development scenarios that include different landing strategies, frac zippering order, fluid intensity, proppant loading, cluster spacing, stage length, well spacing, and depletion levels. The screening is helpful to narrow the list of the key effective parameters to optimize. Tornado charts reveal relative importance of all tested parameters. The results reveal that, within the constraints of this particular study, stage length has largest impact on estimated ultimate recovery (EUR). Well spacing, landing, and fluid loading have a moderate effect. Proppant loading has the least impact. The majority of EUR uplift is associated with higher fluid intensity, shorter stage length, and wider well spacing. Optimal stage length is shown to change as a function of landing depth and is related to geology, geomechanics, and stress shadowing.
All tested scenarios provide different EURs, with different economic outcomes. Opportunity charts are used to identify the most economic field development scenarios. The best opportunities provide similar or higher EUR as of the current base design, but at a lower cost and/or higher rate of return. The best economical cases were recommended for field trials.