Minimize sumps and doglegs to ensure completions to TD

An operator planned a second round of development drilling consisting of five horizontal development wells and a water injector offshore Western Australia. This project involved the subsea tieback of three additional development wells with oil columns less than 66 ft [20 m] thick and horizontal trajectories up to 6,890 ft [2,100 m] long.

Production was in a lower net, interbedded oilfield development unit, which presented reservoir steering challenges not encountered in previous wells. The well plan called for a long horizontal well with a maximum dogleg tolerance of 2°/98 ft [2°/30 m] and minimized sumps to ensure completions would be run to TD.

Detect multiple resistive layers, fluid contacts over long horizontal distances

Schlumberger selected the GeoSphere reservoir mapping-while-drilling service to map multiple resistivity layers in the reservoir, and its experts provided real-time interpretation support. Using deep directional resistivity measurements, the GeoSphere service provides data more than 100 ft [30 m] from the wellbore that can be integrated with interpreted seismic information to refine reservoir structure and geometry interpretation for optimized recovery.

Drilled well on target below top of reservoir

Despite low-resistivity contrasts, the GeoSphere service mapped the multiple resistive layers corresponding to geological interfaces of the reservoir. The top of the reservoir was clearly detected, allowing the operator to focus on rapid well trajectory adjustments to avoid faults and drill the well 3–7-ft [1–2-m] TVD below the reservoir top.

The GeoSphere service provided a depth of investigation not previously available, providing the operator with critical data to help achieve maximum reservoir exposure. As a result, the operator plans to drill four additional wells using this service.