This mainly reflected a planned maintenance shutdown in March and April at producing fields, but it was also partly due to natural decline, according to Mosaic.
Mosaic’s producing fields are all in Queensland.
At the Churchie field, in which Mosaic holds a 49% stake and Santos owns the rest, recent pressure surveys and field production performance have indicated a 27% increase in proven (1P) reserves.
“Material balance and decline analysis interpretation results indicate the current 1P gas reserve can be effectively accessed by current producing wells and a further development well is not required,” Mosaic said this morning.
“The joint venture is planning production testing of Churchie-1 during the September quarter and, if commercially viable, would plan to connect the well for production.”
The main gas zone at Churchie is in the Permian Tinowon sandstone, but Churchie-1 would access Triassic reservoirs in the Rewan sandstone.
Mosaic has also been active at three 100%-held producing fields.
At the Waggamba oil and gas field in PL 202, Waggamba-1H re-entry operations suffered a lengthy delay because of the short supply of directional tools suitable for horizontal drilling. The required slim hole directional tools are being sourced from North America and a rig is on location to resume drilling before the end of the month.
Re-completion of Waggamba-3 for increased oil and gas production is planned for the September quarter using Ensign Rig 5.
Meanwhile, a reservoir sedimentological study is being conducted in conjunction with the Waggamba 3D seismic data volume.
“The aim of the study is to help identify areas with favourable reservoir development which, together with the results from a stress study of the greater Waggamba 3D seismic volume, will allow Mosaic to plan the optimal location of future wells to minimise operational risk and to maximise reservoir deliverability,” the company said.
At Silver Springs, oil production increased from 884 barrels in April to 2953bbl in June.
“This increase is due to the new beam pump installations at East Glen-1 and Taylor-4 completed in April, and also better output from the wells worked over in March and April,” Mosaic said.
“Mosaic continues to assess the commercial viability of installing further rod insert pumps into wells in the Tinker and Roswin areas to increase incremental oil, LPG and gas production.”
At Fairymount, a detailed review of production performance and of 1P reserves was completed during the quarter.
“An opportunity to increase production by installing a pumping unit at Fairymount-6A was identified,” Mosaic said.
“This well was shut-in in 2000 due to the then low oil price. All equipment has been acquired and the work is planned for the September quarter.
“Resumption of drilling at Fairymount-7H oil well was approved and is expected to commence after Waggamba-1H drilling. The aim of this well is to increase oil production and recoverable reserves at this field.”
