Published: 06/26/2014
Published: 06/26/2014
An operator planned to drill several horizontal development wells in offshore Western Australia in oil columns less than 65 ft [20 m] wide and with horizontal trajectories greater than 8,200 ft [2,500 m] long. The field comprises fault terraces that serve as structural and stratigraphic trapping mechanisms. Closure is provided by structural dip, with crossfault shale juxtaposition between terrace blocks. The lower net and interbedded nature of the field presented additional challenges, complicating reservoir steering.
Prior use of GeoSphere reservoir mapping-while-drilling service in the same field yielded successful results. The operator selected this service to achieve similar reservoir mapping and steering objectives. The service provides real-time reservoir mapping that extends the depth of investigation to more than 100 ft [30m] from the wellbore. Using deep directional resistivity measurements from the GeoSphere service to complement surface seismic data, operators can see a clear delineation of fluid contacts and geologic structural dips. With this information, operators are better able to precisely steer the well trajectory in complex reservoirs. Data acquired during steering operations is compared with seismic information to create field development plans.
The GeoSphere service gathered information about the reservoir's structural boundaries to refine and validate existing seismic data. This data helped generate accurate geological cross sections along the length of the two producer wells. Real-time data gave a detailed representation of the highly faulted reservoir and enabled precise positioning of the wells in the target reservoir sands.
The operator updated its geological reservoir model using the information gathered while drilling the two wells and has since drilled two additional wells using the GeoSphere service.
"The GeoSphere servive procides the most technologically advanced multilayer bed boundary mapping in the industry"
Geological Advisor, Operator
Challenge: Continuously map reservoir in real time, delineating layers while steering for maximum exposure into dual lateral production holes; update geological and reservoir model with reservoir mapping data
Solution: Use GeoSphere reservoir mapping-while-drilling service to accurately steer two horizontal wells while mapping reservoir in real time
Results: Generated accurate geological cross sections along two producer wells during successful drain trajectory placements into reservoir sweet spots
