Detailed geological structure with StrataStar™ Service

Overview

A shallow marine depositional environment can create a complex, laterally variable sequence of thin productive sands and non-productive silts and shales. The precise mapping of these layers while drilling optimizes the well path, enhancing reservoir understanding and increasing exposure to the producing sand units. The Halliburton StrataStar™ service is designed to deliver these benefits using deep azimuthal resistivity measurements, which, when combined with advanced inversion processing, maps reservoir and fluid boundaries up to 30 ft (±9 m) from the wellbore.

Challenge

The early adoption of azimuthal electromagnetic logging-while-drilling (LWD) technology by an operator of Alaska’s North Slope necessitated winning confidence in the expected results. Using this complex reservoir as a proving ground, the new StrataStar service was deployed alongside an existing azimuthal resistivity tool in a 6-3/4-in. bottom hole assembly to steer a 10,000-foot-long (3048-meter-long) horizontal section with a goal to verify comparable, if not better, downhole data.

The field trial plan: directly compare the deep resistivity measurements throughout the LWD execution while correlating the wellbore data of the advanced StrataStar service mapping capabilities with traditional techniques, such as gamma-ray sensors.

Solution

Halliburton proposed the StrataStar deep azimuthal resistivity service for its ability to provide a detailed, high-resolution inversion canvas in real time, which was ideal for conducting a rapid, reliable assessment of the Alaska North Slope subsurface geology. The solution also enabled accurate well placement decisions to optimize the well path—even in the complex marine deposits of this reservoir.