Mapping reservoir intervals

An operator performed an LWD operation on a 4,000-ft [1,220-m] lateral in the Woodford Shale. The measurements were run to understand how the formation dip changes laterally and how the reservoir properties vary across the vertical layers. Working with engineers from Schlumberger, the operator integrated offset vertical triple-combo neutron, density, and resistivity measurements with measurements obtained with the EcoScope multifunction LWD service to map nine distinct layers in the Woodford Shale with a thickness of 220 ft [67 m].

Integrating measurements to identify high-quality reservoir intervals

After the well was put on production, the Flow Scanner multispinner production logging tool was run, and data from it was integrated with maps of reservoir zones to identify the most prolific zones within the Woodford Shale. Measurements from the Flow Scanner system determined that more than 90% of the gas was produced from perforations located in three of the nine mapped zones.

These three highly productive layers were adjacent to one another and within 82 ft [25 m] of each other. Furthermore, interpretations derived from the data of EcoScope service and Flow Scanner system showed that perforation clusters placed across higher free gas, lower clay content, and lower calcite volume produced more gas.

Optimizing future wells

Lateral measurements are crucial to place wells in the most productive layers within the Woodford Shale. Placing perforation clusters across zones with the most favorable rock properties should result in stronger performance from all the perforation clusters, ultimately increasing the total well production. The operator will apply lessons learned from this well to optimize future operations. This approach of integrating measurements from vertical logging data, lateral LWD data, and production logs is essential to understand how to optimize production from other heterogeneous shale plays.