Santos Ltd plugged and abandoned the Dorado 3 appraisal well in WA-437-P, located in the Roebuck Basin, in mid-Ocotber 2019, with the âNoble Tom Prosserâ J/U leaving the wellsite on 17 October. The well had been drilled to a total depth of 4,643 m. Dorado 3 was the second appraisal at the Dorado discovery and was spudded, in a water depth of 90 m, on 28 July 2019  Testing was undertaken on the well at total depth. On 8 October 2019 the operator reported that the second flow test, over the Caley interval, had been completed, with successful results. The test was conducted over the 3,999 â 4,015 m interval, over an 11 m net Caley section, with flows of approximately 11.1 Mbo/d and 21 MMcfg/d observed (the maximum possible). As with the initial Baxter unit test, flows were constrained by surface equipment. The flows from the Caley indicate that production rates of up to 30 Mbo/d per well could be achieved. With both flow tests completed, the operator plans to evaluate the potential of non-constrained production tests.  Testing of the Caley unit was undertaken after successful completion of testing the Baxter reservoir. Santos reported on 23 September 2019 that flow testing of the Baxter gas and condensate reservoir produced excellent results. Santos reported that Baxter flow testing has confirmed high productivity and fluid quality from the reservoir. The testing was first reported to be successful by venture partner Carnarvon Petroleum on 19 September 2019. Over a 12-hour period, a maximum flow rate of 48 MMcf/d was achieved, along with 4,500 bbl/d of associated condensate through a 60/64" choke. Testing was conducted across the reservoir section between 4,136 and 4,156 m. Preliminary interpretation of the well test indicates improved condensate gas ratio which could result in higher well deliverability upon production according to Santos.   Prior to preparing for flow testing, in early September 2019, the operator undertook wireline logging, having reached a total depth of 4,643 m. Initial results from the wireline logging confirmed the presence of hydrocarbons within the Dorado reservoirs at this location, in the Caley, Baxter and Crespin units.   Within the Caley reservoir, around 53 m net oil pay was observed, with a porosity of around 16%. Within the Baxter Member, around 9 m net pay was encountered, with 12% porosity and no water. The pressure data indicated connection with the Dorado 1 and 2 wells. The Crespin unit was not expected to be hydrocarbon bearing, but a hydrocarbon column of around 5 m was encountered, with average porosities of around 9%. Wireline logging has indicated no hydrocarbons within the Milne Member at this location, though a 60 m core was extracted from the Milne reservoir unit in early September..  Initial cores, of 175 m, were acquired from the well across the Caley and Baxter reservoirs. This was lower than original plans, which were to see 230 m of core, with Carnarvon reporting that the non-reservoir sections were drilled, rather than cored. Logging while drilling was undertaken across the cored sections, which have indicated porosity and permeability across the reservoirs, with indications of hydrocarbons. The wireline logging at total depth will provide more results on the reservoirs intersected.  The Dorado 3 well was further appraising the Dorado discovery, which was made in August 2018. The Dorado 1 well made one of the largest oil discoveries on the northwest shelf. Oil was encountered in the primary target Caley Member, which forms the objective for the Dorado appraisal wells. Carnarvon reported that an âexcellent reservoirâ unit had been encountered within the Caley target, with 79.6 m net pay over a 96.1 m gross interval. Average porosity of 20%, with 82.5% hydrocarbon saturation and permeability between 100 and 1,000 mD has been measured within the Caley. Light oil was also recovered to surface as part of the logging and evaluation programme, estimated at 49.6Âº API. In the discovery well, additional oil pay was encountered within the Crespin and Milne members. Light oil was recovered from both the Crespin and Milne units during evaluation. Net pay of 22 m, across a 50 m gross interval, was confirmed in the Crespin and 18 m net pay within a 30 m gross interval within the Milne Member. Average porosities of 14% and 13% were observed respectively.  Dorado 2, the first appraisal well in the programme was spudded in early May 2019. Wireline logging results confirmed the pre-drill oil resource of the field and could provide a significant gas resource increase thanks to large hydrocarbon columns encountered in the Baxter and Milne reservoirs. At Dorado 2, within the primary target Caley Formation, 85 m of net reservoir was encountered. The Main Caley level presents an oil-water contact at 4,003 m, with 40 m of net oil pay. Overlying this, in the Upper Caley sands, Santos expects an additional 11 m of net oil pay, determined from early wellsite analysis. A further 32 m of net pay was encountered across the Baxter and Milne sandstone intervals which is currently interpreted to be gas bearing.   The Dorado 2 and 3 wells were drilled to evaluate the extent of the Dorado resources, to assist in development planning. Better resource estimates will be made upon the conclusion of drilling. Oil will be the key target, with the joint venture reporting that development of oil would be a lower cost and quicker return, which could then lead to a wider field development including gas and condensate.  If development is deemed suitable after appraisal drilling, Final Investment Decision (FID) is hoped to be reached in 2020. Dorado could be developed alongside the Roc discovery, which lies to the north and was discovered in 2016.  WA-437-P, which covers an area of 4,871 sq km, was awarded on 4 August 2009. Participants in the permit are: Santos WA Northwest Pty Ltd (80% plus operatorship) and Carnarvon Petroleum Ltd (20%).
Santos Ltd plugged and abandoned the Dorado 3 appraisal well in WA-437-P, located in the Roebuck Basin,The test was conducted over the 3,999 â 4,015 m interval, over an 11 m net Caley section, with flows of approximately 11.1 Mbo/d and 21 MMcfg/d observed (the maximum possible). 