I found this great summary of previous works on L7 in the...

I found this great summary of previous works on L7 in the Arranoo No.1 Well Completion Report. This is from back in May 1994, but it was one of the most recent exploration holes drilled on L7.

This is copy pasted from a scanned document so there some typos etc that arent in the original.

The Mt Horner Oilfield was discovered by WAPET (WestAustralian Petroleum Co. Ltd.) in 1965. Mt Horner No 1, produced oil from theEarly Triassic Arranoo Sandstone reservoir in the Kockatea Shale, at a rate of40 BOPD (6.4m 3 /day) and 40 BOWPD during a 42 day production test. This flowwas on the upthrown side of the Mt Horner Fault and was dependent on faultseal. At that time the flow rate was non-commercial.

Mt Horner No 2 was also drilled in 1965, approximately 2kilometres to the south southwest of Mt Horner No 1, again on the upthrown sideof the Mt Horner Fault. This well encountered minor hydrocarbon shows, but wasstructurally low to Mt Horner No 1. Open hole drill stem tests on theCockleshell Gully Formation and the Wagina Sandstone failed to produce anyhydrocarbons. It was not at the time realised that the well was drilled on aseparate structure to Mt Horner No. 1.

Mt Horner No. 2 was also abandoned and little furtherwork was carried . out until 1976 when XLX N.L. was granted three graticularblocks designated EP-96 around the area. In 1980, EP-96 was farmed out toPacific Basin Exploration Pty Limited and Mt Horner No's 3 and 4 were drilledin that year. Mt Horner No 4 was suspended pending further testing.

In 1981 Mt Horner No 5 and Georgina No 1 were drilled.Georgina No 1 was plugged and abandoned, with hydrocarbon shows in theCattamarra Coal Measures Member and Permian Sandstones. Drill stem tests onthese two sections again failed to produce significant oil, but a thin layer ofoil was reported on the water produced from the Cattamarra Coal MeasuresMember.

Oil shows in Mt Horner No 5 were not tested by the jointventure existing at the time, due to legal disputes between the parties. Thesewere resolved in 1983 and Quadrant Corporation took over operatorship of thefield and drilled Mt Horner No 6which was plugged and abandoned. Mt Horner No 5was successfully production tested from what was thought to be Basal TriassicSandstone (Wagina Sandstone), but is now known to be Early Permian Irwin RiverCoal Measures. A Production Licence was granted in 1983 and in 1984 limited oilproduction from this well commenced.

In 1986 a new Mt Horner joint venture, operated byBarrack Energy Ltd. carried out testing over a new zone on the downthrown sideof the Mt Horner Fault in Mt Horner No 5 through 7" (178mm) casing whichresulted in oil production. from a thin sandstone reservoir ("B" sand),near the top of the Cattamarra Coal Measures Member.

Re-mapping of the Mt Horner structure, at top CattamarraCoal Measures Member level suggested the producing zone in Mt Horner No 5("B" sand) lay within a small structural closure which possiblyextended to the northeast. Mt Horner No 7 was drilled to test this extension,however the "B" sand was not encountered, pinching out between thetwo wells.

The discovery of the deeper "F" sand in MtHorner No 7 during May 1987, led to a re-appraisal of the Mt Horner field. Thiszone produced 39 barrels of 35.5 API oil on Drill Stem Test, with a predictedoil/water contact at - 1024mSS. An appraisal/ development programme wasproposed and in January to April 1988 the following wells were drilled; MtHorner No 4A, 5A, 8 and 9. These were all oil producers from the "F"sand interval, Mt Horner No 9 being the best producer. Mt Horner No 6previously drilled in 1981 was also re-entered, but produced formation water ona Drill Stem Test over the srun~ interval and was plugged and abandoned.

Mt Horner No 10. drilled in 1989 was a successfulappraisal well towards the south-east of the Mt Horner field. Mt Horner No 11(1989), a stepout well across a saddle to the south-east of the main field, didnot have oil shows. Mt Horner 12, drilled in 1992, encountered hydrocarbons ina new · reservoir know as the "L" sand, but this failed to producewhen tested. The well was successfully completed as an "F" sandproducer. Mt Horner 13 __ tested northwesterly extension of the field where thespill point was thought to be, but was found to be structurally low to MtHorner 12.

Mt Horner 14 drilled immediately before Arranoo No. 1_tested a structural high between Mt Horner 12 and Mt Horner 7. The well was notas high as had been mapped due to anomalously high velocities in the Jurassicsection, but was completed as an oil producer from the "F" sand.

All these wells crossed the Mt Horner Fault to test thePermo- Triassic section on the upthrown side of the fault. In each casehydrocarbon shows were encountered, but saturations were not high enough forproduction.

During 1992 and 1993 considerable technical effort wasmade to resolve velocity anomalies over the Mt Horner Field and surroundingareas. All seismic lines of different vintages had their statics recalculatedusing uphole data from the 1993 Allanooka Seismic survey and from re-pickedprevious uphole data. Average velocities were calculated to the top K unit(base Cattrunarra Coal Measures marker) using stacking velocities from seismiclines. These were matched to the existing Mt Horner well data to produce anaverage velocity map from which depth maps were produced at top K unit and Fsand levels. The drilling of Mt Horner 14 immediately prior to Arranoo No. 1showed that not all velocity anomalies had been resolved by this method andfurther work needs to be carried out.