Up to December 2014, the Warro Field was held in Locations within Exploration Permits 321 and 407. The Warro Joint Venture successfully applied for the field Locations to be converted to Retention Leases 6 and 7, awarded in December 2014. At the same time, the remainder of EP407 was relinquished in full along with four graticular blocks in EP321.
The Warro Joint Venture also successfully negotiated a Native Title Agreement with the Yued people during 2014. This agreement allows for field operations through development and production to take place.
In 2015, Latent Petroleum, as operator of the Warro Gas Project, conducted a third phase of work. This included the drilling of Warro-5 and 6, both wells are more than 4km deep.
Drilling of Warro‐5 commenced 16 August 2015 but the well needed to be side-tracked at 1867m when fishing operations failed to recover the stuck pipe and other downhole equipment. This equipment was cemented in place and the well redirected around it towards the original target as Warro‐5ST.
The planned TD of Warro-5ST was expected to be 4280m TVDRT but the well drilled to a final TVD of 4418m due to strong gas shows during the operation. The well was suspended on 30 September with 5 ½” casing run to TD and Enerdrill Rig 3 was mobilised to Warro‐6 at a location approximately 3km to the northwest of Warro‐5ST.
Warro‐6 was spud on 11 October 2015. Warro‐6, a vertical well, was drilled to a total depth of 4520m TVDRT prior to setting 5 ½” casing to TD. Warro‐6 continued to encounter strong gas shows to the base of the well. The bottom of the main reservoir section was reached at 4462.5m RT at the top of a regional shale unit (Cadda).
The first frac of Warro-5, conducted on 7 December, encountered some unexpected hole conditions and the frac spread was moved to Warro-6 to commence fraccing while the situation at Warro-5ST was assessed.
The fraccing of Warro-6 commenced on 13 December and all three stages were successfully completed. Initial flowback of fluids was completed with sufficient gas returned to surface for a sustained flare (exact gas quantities could not be measured at this time). Well completions were concluded in mid-January 2016 and extended well testing is now underway.
Warro-5ST fracture stimulation operations concluded in January 2016 and the well completions took place in January 2016.
The Warro Testing programme commenced at the end of January, 2016 at Warro-6 and was followed in early February by flows from Warro-5. Following a short period when the wells flowed with the assistance of jet pumps, both wells have achieved unassisted natural flow and continue to flow both gas and water. Following a period of testing, Warro-5 and 6 were shut-in in late March. After running PLT in Warro-6, the well is undergoing cycling of 12 hours on and 12 hours off utilising downhole separation to increase gas rates and reduce water ingress. Warro-5 is currently shut in while wellhead pressure is being monitored.
Warro-4 was re-entered in late June and and retesting operations commenced. Equipment was installed on site and the secondary target, “B” sand reservoir section, was allowed to flow. This resulted in a small amount of “blow-down gas” before the well ceased to flow and was shut-in.
The subsequent operation was to flow the main objective, the topmost part of the “C” reservoir section. Following a three week well test, Warro-4 was suspended while data was gathered for a review phase.
The 2017 work programme focussing on a technical review of the four wells the JV have drilled to date was approved by Alcoa in late 2016.
All work fully complies with the Environmental Protection Authority’s (EPA) guidelines on hydraulic fracturing released in December 2014. The work has also undergone a stringent review by the WA Department of Mines and Petroleum with input from the Departments of Water; Agriculture; and Parks & Wildlife.