Union-Kern-A.O.G. Moonie No. 1 was the third wildcat drilled by Union Oil Development Corporation in its current exploratory effort in the Surat Basin in Queensland. The drilling of the initial test in the Basin, Union-Kern-A.O.G. Cabawin No. 1, resulted in a sub-commercial discovery of oil in an eight-foot sand body (9928-9936 feet) in the Permian Kianga Formation. The second test, Union-Kern-A.O.G. CabawinEast No. 1, was programmed on a distinct closure separated from the domal closure of Cabawin No. 1 by a major transverse fault. The test was designed to evaluate the thesis that the oil bearing sandstone encountered in the first well might thicken appreciably eastward. Cabawin East was dry; the Permian oil bearing sandstone was not developed at the second location.
After additional geophysical work, Union-Kern-A.O.G. Moonie No. 1 was programmed approximately 20 miles south of Cabawin East as a structural test of the petroleum potential of the Triassic lower Bundamba sandstones. At the location of the test, sands of the lower member of the Bundamba Formation in domal closure overlie a truncated and faulted Permian section. The desirability of the test was suggested from information gained in the Cabawin area where permeable lower Bundamba sands were indicated to be the most favourable reservoir rocks, and where the Permian section was indicated to be the probable source of the oil encountered. At the location of the test a maximum of 150 feet of vertical closure over ten square miles was indicated in the Bundamba section. No closure could be postulated for the steeply dipping Permo-Carboniferous sequence unconformably present beneath the Bundamba. The test was based on the thesis that oil generated in the Permian section would
migrate up dip, and be trapped in the porous sands of the Bundamba closure. To enhance the prospect further, seismic work indicated that a portion of the lower Bundamba which consisted of a less permeable section in the Cabawin wells, had been overlapped at the proposed location and that porous and permeable sands of the unit might rest directly on the unconformity.
The well was spudded in on 12th November, 1961; 13 3/8" casing was cemented at 1636 feet, and drilling and coring was continued to a depth of 5925 feet. At that depth a 74-minute open-hole formation test of the interval 5816-5925 feet yielded black 48 API gravity oil flowing at an estimated rate of 250 barrels per day and water (29 grains/gallon), at an estimated rate of 250 barrels per day. Gas accompanying the flow was estimated at 200 Mcf/D.
The well was drilled and cored ahead to a total depth of 6106 feet. Casing (5 1/2") was cemented at 5950 feet, and the well was completed through perforations of the interval 5798-5840 feet. A sustained testing programme was conducted from 23rd December, 1961 to 18th February, 1962. At the end of this period the well was producing 666 barrels per day of 45 API gravity oil with 124 Mcf/D of gas through 18/64" choke, with casing and tubing wellhead pressures at 600 p.s.i. and 560 p.s.i. respectively. A total of 7445 barrels of crude oil and 1320 Mcf of gas were produced during the testing period. The well was shut in on 18th February, 1962 for final pressure and temperature surveys and was suspended on 21st February, 1962, retained in a condition for production at any future time.
