Integrated Reservoir Simulation and Development: Reindeer Gas Field, Carnarvon Basin, NW Shelf, Australia

Pivnik, David A.; Best, Dennis; Marshall, Craig; Jackson, Elliot
Apache Energy, Perth, WA, Australia

Recent exploration and development activity on the NW Shelf, Australia has focused on LNG and foreign export. One exception is Reindeer Field, which came online in December, 2011 and supplies natural gas to the Western Australian domestic market. Reindeer is a ~500 BCF offshore gas field hosted by Middle Jurassic fluvial-deltaic sandstone trapped in a 3-way closure on the margin of the Dampier sub-basin (Carnarvon Basin, NW Shelf, Australia). It was discovered in 1997 with the Reindeer-1 well. Because of low demand for domestic natural gas, the field sat dormant. After the Gnu-1 well successfully appraised the field in 2006, we began a concerted, integrated effort to accurately estimate reserves and plan for development of the field. This included re-mapping the 3D seismic data and incorporating all existing well log and core data into a 3D geo-cellular model for reservoir simulation. Results were encouraging enough to move forward with a development plan including pre-drilling 3 wells, building and installing an offshore platform with a >100km pipeline to the shore and building a gas-processing plant at Devil Creek, now the 3rd domestic gas hub in Western Australia.

The 3 development wells were located to optimize recovery from potentially compartmentalized structural blocks. Data from new logging (including borehole images) and routine and special core analyses were integrated with the sedimentological facies and structural features identified in core. Reservoir quality is excellent, with a high net:gross, porosity averaging 18-20% and multi-Darcy permeability. Pyrite is present and can affect permeability as well as water-saturation calculations. Deformation bands are present, but do not negatively affect permeability. Capillary pressure data were used to calculate field-wide water saturations, as well as assist in rock-typing. The 3D seismic data is of fair quality; reservoir fluids cannot be detected, and smaller scale faults are not imaged.

Reservoir parameters derived from the above analyses were used to update the 3D model and conduct new reservoir simulations that included multiple drive mechanisms, fault transmissibilities, perforation strategies and combinations of flowing wells. These simulations helped us design well completions and production plans and are being used to monitor well performance, pressure depletion and water influx and to infer the significance of fault or stratigraphic compartmentalization.

AAPG Search and Discovery Article #90155©2012 AAPG International Conference & Exhibition, Singapore, 16-19 September 2012