Unconventional tight shale oil and gas plays have recently become major targets for exploration companies. What started in the United States as a new way to exploit these plays using extended horizontal drilling and hydraulic fracturing technologies has now expanded worldwide. Current development of these plays is a statistical process where evenly laid out drilling locations allow a company to hold land leases and ensure a projected ROI based on early initial and cumulative production numbers from neighboring wells. The challenge then becomes the design of the infill drilling program and how best to maximize the ultimate recovery of resource from each field in a timely fashion.