Optimized Field Development Planning Using Geostatistical Modeling – Case Study from the Sooner Field, Colorado, USA

Defining the drilling sequence and location of wells in a new field is critical to the ultimate economics of a field development project. In this first of a two part study, we propose a geostatistical stochastic modeling methodology to estimate reservoir properties at periodic intervals in the drilling program. As a new well is completed in the reservoir, porosity log data from this well and all previously drilled wells is used to compute P10, P50 and P90 porosity models from 100 stochastic realizations. Gross and net porosity maps are derived from the P50 model and can be used to optimally select new well locations. The P10 and P90 models can be used to place probable upper and lower limits on the expected porosity at the proposed well locations. Data from a small oil field is used to validate the proposed methodology. In this phase of the study we compute P10, P50 and P90 porosity models of the reservoir using wells in the order in which they were drilled. We demonstrate that reliable reservoir porosity estimates and distributions can be realized after drilling 8 to 10 wells in a 35 well program.