Reservoir-Navigation System and Drilling Technology Maximize Productivity and Drilling Performance in the Granite Wash, US Midcontinent

Abstract

Summary The Granite Wash unconventional gas and oil play of the US midcontinent has a multitrillion-cubic-feet-equivalent upside potential. The condensates and natural-gas liquids associated with this gas play make it one of the most-prolific and fastest-growing unconventional fields in North America. However, efficient extraction of hydrocarbons from the Granite Wash play poses drilling and geological challenges. The Granite Wash deposit has significant lateral variation, with extremely abrasive thinly bedded sandstones. Geological complexity of this field requires precise placement and navigation of the wellbore in real time to overcome the variable characteristics of the reservoir. To overcome these challenges, logging-while-drilling (LWD) technology was used in conjunction with geosteering. An azimuthal gamma ray image was used to determine formation bed dip and stratigraphic complexity within the reservoir. Multiple-propagation resistivity measurements were used to correlate position within the reservoir and indicate formation porosity. The LWD data was transmitted in real time by means of satellite to a remote reservoir-navigation center where the reservoir-navigation engineer incorporated the real-time data into the geological model. This strategy has been implemented to drill with excellent results, as compared with the offset wells. The initial production rate obtained was 19.4 MMcfe/D (cfe = cubic foot equivalent). The well was completed 10 days ahead of schedule, resulting in significant cost savings. With the successful implementation of real-time reservoir-navigation and drilling technology, the operator accelerated their drilling program. The results are significant organic production growth, improved drilling performance, precise placement of the wellbore, and significant reduction in rotating hours at lower drilling and production costs.