Announcement PDF ASX Announcement 28 October 2025 Quarterly report for the period ended 30 September 2025 Bass Oil Limited (ASX:BAS) is an Australian-listed oil producer that holds a majority interest in eight permits in the Cooper Basin (Australia) including the 100% owned Worrior and Padulla oil fields and a 55% interest in a South Sumatra Basin (Indonesia) KSO. The Company is debt free and committed to creating value by leveraging the competitive strengths of its team, operating capability, reputation, and relationships in both Australia and Indonesia. Highlights • Quarterly oil sales were A$1.62 million, at an average price of A$100.84 (US$66.58) per bbl • Production, net to Bass in the June quarter, was 20,905 barrels, averaging 227 bopd • Production enhancement program completed in early October - increases Indonesian oil production by 20% • Vanessa acquisition - regulatory approval expected shortly • Bass is finalising R&D tax credit claim for the deep coal gas project - to lodge this month Bass Oil Managing Director, Mr Tino Guglielmo, commented: ”This quarter, Bass progressed towards its strategic aim to become a gas producer by working constructively with the regulator to secure approval for the acquisition of a 100% interest in the Vanessa gas field and facilities. The Company made good progress in discussions for the sale of Vanessa gas. In all likelihood Vanessa will be the first field to be brought into production satisfying Bass’ long held ambitions to enter the East Coast Gas Market. Vanessa, the Kiwi project, and the PEL 182 deep coal gas play are key pillars for the Company’s future growth and will be progressed vigorously as we focus on growing Bass into a mid-tier oil and gas producer.” Table 1 – Key Performance Metrics Key Performance Metrics Sep Qtr Q3 FY25 Jun Qtr Q2 FY25 Qtr on Qtr Change 2025 YTD 2024 YTD Yr on yr Change Net Production1 (mbbl) 20.91 21.29 -1.8% 63.40 75.80 -16.4% Net Entitlement to Bass (mbbl) 15.52 15.50 0.1% 47.22 51.89 -9.0% Sales Revenue ($M) 1.62 1.69 -4.2% 5.28 4.39 20.3% Average Oil Price ($bbl) 66.58 66.85 -0.41% 70.61 80.36 -12.1% Cash ($M) 1.36 1.96 -30.6% 1.36 1.38 -1.3% Note 1: Net Indonesian Production and Sales are reported at 55% share and excludes the deduction of Domestic Market Obligation (DMO). Note 2: The KPM, including Net Entitlement to Bass, for Sep Qtr Q3 FY25 & Jun Qtr Q2 FY25 includes both Cooper Basin and Indonesian results (net of DMO). Note 3: Revenue from the sale of oil is recognised at the point in time when the customer obtains control of the oil. Production Figure 1: Bass Oil Quarterly Production Oil production for the September quarter was 20,905 barrels of oil, consistent with 21,285 barrels in the June quarter. Production net to Bass for the quarter averaged 230 bopd. Both the Cooper Basin and Tangai Sukananti fields continued to perform as expected. Oil Price Bass realised an average oil price for the September 2025 quarter of US$66.85 down 0.4% from the June quarter due to a softening of the oil markets. Oil sales in Indonesia are tied to ICP pricing which in turn is linked to the benchmark Brent crude. Cooper Basin oil sales are also linked to the benchmark Brent crude. The Company has no oil hedges in place. COOPER BASIN Worrior and Padulla Oil Fields (Bass 100%) Production for the September quarter from the Worrior and Padulla oil fields averaged 93 bopd, down 2% on the June quarter. Revenue for the quarter from the Cooper Basin was A$0.61 million from the sale of barrels of oil, down 22.5%. This was primarily due oil sales being curtailed following a rain event which closed roads to trucking for much of September. The roads reopened in late September, and trucking resumed. The rains had no impact on production as there is sufficient storage capacity in the field. The Company received an average oil price for the September 2025 quarter of A$106.10 per barrel. Operations Production operations at both the Worrior and Padulla facilities recorded uptimes of 99%. The flooding events reported earlier in the year in the Cooper Basin are receding and have not interrupted Bass’ oil production or sales. 13.629 11.717 12.590 12.350 9.243 9.490 8.696 8.555 0.000 5.000 10.000 15.000 20.000 25.000 Production (Kbbl) Bass Oil Quarterly Production (Kbbl) Indonesian Production (55% Bass) Cooper Basin Production (100% Bass) Sep Qtr Q3 FY25 Jun Qtr Q2 FY25 Qtr on Qtr change Crude oil sales (bbls) 5,771 7,447 -22.5% Total sales revenue ($M) $0.61 $0.79 -22.2% Crude oil production (bbls) 8,555 8,696 -2% Table 2 – Cooper Basin Production & Sales Cooper Basin Gas Vanessa Gas Field (Bass acquiring 100%) In late May Bass announced that it is to acquire 100% interest in the Vanessa gas field (see Figure 1) for a nil cash consideration. The transaction will see Bass assume the future rehabilitation liability with the vendor making a significant contribution to the rehabilitation cost. The Company is well advanced in negotiations with gas buyers interested in production from the re-start of the Vanessa field. Bass is also close to securing the relevant regulatory approvals for the transaction. The Vanessa gas field acquisition (Figure 1) includes a gas processing facility and a 5-kilometre pipeline connecting to the Cooper Basin gas transmission network. Detailed planning for the certification and recommissioning of the Vanessa well, facilities and pipeline has commenced. The Vanessa acquisition is important to the Company as it provides the opportunity for: • First gas sales - The recertification and recommissioning the Vanessa gas production facility and pipeline would enable the Company’s first gas sales into the east coast gas market. • Reserve growth - by proving up significant untested conventional and tight gas potential in both the Toolachee and Patchawarra formations that can be accessed from the well by fracture stimulation. • The advancement of activities to commercialise the deep coals - The Vanessa well penetrated the entire Permian sequence of sediments, including the deep coals. Bass considers this location ideally situated to test the commercialisation potential of the large deep coal resource in PEL 182 without incurring the cost of drilling a dedicated well. Figure 2: Map of Bass permit PEL 182 displaying Vanessa gas field PEL 182 Deep Coal Commercialisation Study – Phase 2 (Bass 100%) Bass and SLB have finalised the scope of phase 2 of the study which SLB will lead. In phase 1 the geomechanical model built by SLB used the Vanessa 1 well as the ‘type well’ for the study. The study will focus on well and fracture stimulation design for economic exploitation of this significant resource. The Santos led Cooper Basin JV is focusing its efforts to commercialize this resource in 2025. Santos is planning to drill two wells in this 12-month period to trial the use of high angle/horizontal well technology along with multi-stage fracking to deliver a commercial production pilot. The first of these wells will spud early this quarter and is scheduled for completion and fracture stimulation before year end. Success from this program will be directly applicable to Bass’ commercialisation efforts. Triassic Gas Study/Kiwi 1 Field Development (Bass 100%) Discussions with the Cooper Basin Joint Venture continue for the transportation and processing options for gas and gas liquids to be produced from the Kiwi field. Bass continues to pursue funding options, including farm down, for the Kiwi gas field development. The Company has commenced the mapping phase of a study aimed at identifying follow-up opportunities to the Kiwi gas discovery. The team has already identified at least two additional gas prospects south of the Kiwi gas field that enhance the Kiwi South stratigraphic trapping potential of the play. The Company will provide a separate update on this work. The study includes the reprocessing of the Dundinna 3D seismic survey to improve the imaging of the target hydrocarbon reservoirs. Figure 3: Map of Bass’ Kiwi Gas Field – Northern Cooper Basin Triassic Gas and Oil Play INDONESIA Tangai-Sukananti KSO (Bass 55% and Operator) The Company produced 12,350 barrels of oil (Bass share) during the quarter down 1.9% on June quarter and sold 12,428 barrels of oil (Bass share) similar to June 2025. The net entitlement oil to Bass was 9,745 barrels for the September 2025 quarter after Domestic Market Obligation (DMO). Figure 4: Tangai-Sukananti Quarterly Production Production Enhancement During the quarter Bass’ Indonesian team completed a three well production enhancement program aimed at achieving a material increase in oil production from both the Bunian and Tangai fields. The program has resulted in an increase in field production of some 20% with the final well, Tangai 5 still cleaning up. The full benefit of the program will be realised in the coming Quarter. Field Development Planning continued for the drilling of the Bunian 6 development well, south-west of the prolific Bunian 3 well. The final materials required for the drilling of the Bunian 6 oil development well, being the well casing and tubing, have been delivered to site. As previously reported, Pertamina advised that there is no slot available on their drilling program to drill the well. Bass is currently evaluating responses from a tender issued for drilling services. The Company will advise the timing of drilling when a rig has been secured. Figure 5: Bunian 6 Well pad 13.629 11.717 12.590 12.350 0.000 5.000 10.000 15.000 20.000 25.000 30.000 Production (Kbbl) Tangai-Sukananti Quarterly Production (55% Bass) Oil Price The Company realised an average oil price for its Indonesian oil production in the September 2025 quarter of US$65.42. Oil sales in Indonesia are tied to ICP crude pricing which is linked to the benchmark Brent crude. Figure 6: Tangai-Sukananti KSO location map CORPORATE Cash Position As of 30 September 2025, Bass’ cash reserves totalled $1.36 million. The Company paid an additional installment of $94k towards its future rehabilitation liability relating to its Cooper Basin properties. The cash reserves exclude some $3.7 million in cash which has been placed on deposit to support rehabilitation bonds in favour of the South Australian Department of Energy and Mining for the future rehabilitation of wells and facilities in the Cooper Basin. The Company carries no debt. Revenue Oil sales for Bass totalled A$1.62 million for the quarter down 4.2% from the previous quarter. Research and Development Tax Credit The Company is preparing to lodge a Research & Development claim for work carried out in FY24 to commercialise the significant gas resource known to be contained in the deep coals within the Bass’ 100% owned PEL 182. If successful, the Company will receive a 43.5% cash rebate of all qualifying expenditure. TENEMENT HOLDINGS The Company periodically reviews and updates the prospectivity of its exploration land holdings to minimise its holding costs whilst retaining the most prospective tenements. Table 3 – Bass Oil Interests Tenement Location Interest owned Interest acquired/farm in during the quarter Interest disposed/farm out during the quarter Tangai-Sukananti KSO Indonesia 55% - - PPL 207 (Worrior) Cooper Basin 100% - - PPL 221 (Padulla) Cooper Basin 100% - - PRL’s 231-233 (Ex PEL 93) Cooper Basin 100% - - PRL’s 207-209 (Ex PEL 100) Cooper Basin ~74% - - PRL’s 188-190 (Ex PEL 110) Cooper Basin 100% - - PRL’s 245-246 (Ex PEL 90K) (Kiwi) Cooper Basin 100% - - PEL 182 Cooper Basin 100% - - This ASX announcement was authorised for release by the Bass Oil Limited Board of Directors. For further information, please contact: Tino Guglielmo Managing Director Bass Oil Limited Ph: +61 3 9927 3000 Email: tino.guglielmo@bassoil.com.au Notes Prospective Resources are those quantities of petroleum estimated, as of a given date, to be potentially recoverable from undiscovered accumulations by application of future development projects. The estimated quantities of petroleum that may potentially be recovered by the application of a future development project(s) relate to undiscovered accumulations. These estimates have both an associated risk of discovery and a risk of development. Further exploration appraisal and evaluation is required to determine the existence of a significant quantity of potentially recoverable hydrocarbons. In accordance with ASX Listing Rule 5.43 the Company confirms that references to prospective resources have previously been announced (16/11/2022 and 18/04/2024). The Company confirms that it is not aware of any new information or data that materially affects the information included in this announcement and that all the material assumptions and technical parameters underpinning the estimates in this announcement continue to apply and have not materially changed. Glossary BOPD Barrels of oil per day BOEPD Barrels of oil equivalent per day mbbl Thousands of barrels of oil mmbbl Millions of barrels of oil DMO Domestic Market Obligation (for Oil) JV Joint Venture TS Tangai-Sukananti KSO KSO 'kerja sama operasi' (Indonesian) – meaning an operation cooperation contract Qtr Quarter Qtr on Qtr Quarter on Quarter Yr Year Yr on Yr Year on Year $M Millions of dollars About Bass Oil Limited: Bass Oil Limited (ASX:BAS) is an Australian-listed oil producer that holds a majority interest in eight permits in the Cooper Basin (Australia) including the 100% owned Worrior and Padulla oil fields and a 55% interest in a South Sumatra Basin (Indonesia) KSO. The Company is debt free and committed to creating value by leveraging the competitive strengths of its team, operating capability, reputation, and relationships in both Australia and Indonesia. Bass is building a substantial onshore Australian and Indonesian oil & gas business with a clear focus on expanding production in the Cooper Basin and in South Sumatra. Bass has a strong and committed shareholder base with the Board and management holding over 10% of the issued capital. Rule 5.5 ASX Listing Rules Appendix 5B (01/12/19) Page 1 + See chapter 19 of the ASX Listing Rules for defined terms. Appendix 5B Mining exploration entity or oil and gas exploration entity quarterly cash flow report Name of entity BASS OIL LIMITED ABN Quarter ended (“current quarter”) 13 008 694 817 30 September 2025 Consolidated statement of cash flows Current quarter $A’000 Year to date (9 months) $A’000 1. Cash flows from operating activities 1,702 5,715 1.1 Receipts from customers 1.2 Payments for - (a) exploration & evaluation (if expensed) (b) development - (c) production (1,187) (3,813) (d) staff costs - (e) administration and corporate costs (439) (956) 1.3 Dividends received (see note 3) - - 1.4 Interest received 14 98 1.5 Interest and other costs of finance paid (5) (12) 1.6 Income taxes paid (29) (63) 1.7 Government grants and tax incentives - - 1.8 Other (provide details if material) - - 1.9 Net cash from / (used in) operating activities 56 969 2. Cash flows from investing activities 2.1 Payments to acquire: (a) entities (b) tenements (c) property, plant and equipment (127) (534) (d) exploration & evaluation (if capitalised) (324) (735) (e) investments (f) other non-current assets Appendix 5B Mining exploration entity or oil and gas exploration entity quarterly cash flow report ASX Listing Rules Appendix 5B (01/12/19) Page 2 + See chapter 19 of the ASX Listing Rules for defined terms. Consolidated statement of cash flows Current quarter $A’000 Year to date (9 months) $A’000 2.2 Proceeds from the disposal of: (a) entities (b) tenements (c) property, plant and equipment - 47 (d) investments (e) other non-current assets 2.3 Cash flows from loans to other entities 2.4 Dividends received (see note 3) 2.5 Other (Deposit into restricted cash) (95) (95) 2.6 Net cash from / (used in) investing activities (546) (1,317) 3. Cash flows from financing activities - 925 3.1 Proceeds from issues of equity securities (excluding convertible debt securities) 3.2 Proceeds from issue of convertible debt securities 3.3 Proceeds from exercise of options 3.4 Transaction costs related to issues of equity securities or convertible debt securities (27) (27) 3.5 Proceeds from borrowings 3.6 Repayment of borrowings 3.7 Transaction costs related to loans and borrowings 3.8 Dividends paid 3.9 Other (Lease payments) (38) (86) 3.10 Net cash from / (used in) financing activities (65) 812 4. Net increase / (decrease) in cash and cash equivalents for the period 4.1 Cash and cash equivalents at beginning of period 1,962 991 4.2 Net cash from / (used in) operating activities (item 1.9 above) 56 969 4.3 Net cash from / (used in) investing activities (item 2.6 above) (546) (1,317) 4.4 Net cash from / (used in) financing activities (item 3.10 above) (65) 812 Appendix 5B Mining exploration entity or oil and gas exploration entity quarterly cash flow report ASX Listing Rules Appendix 5B (01/12/19) Page 3 + See chapter 19 of the ASX Listing Rules for defined terms. Consolidated statement of cash flows Current quarter $A’000 Year to date (9 months) $A’000 4.5 Effect of movement in exchange rates on cash held (41) (89) 4.6 Cash and cash equivalents at end of period 1,366 1,366 5. Reconciliation of cash and cash equivalents at the end of the quarter (as shown in the consolidated statement of cash flows) to the related items in the accounts Current quarter $A’000 Previous quarter $A’000 5.1 Bank balances 1,366 1,962 5.2 Call deposits 5.3 Bank overdrafts 5.4 Other (provide details) 5.5 Cash and cash equivalents at end of quarter (should equal item 4.6 above) 1,366 1,962 6. Payments to related parties of the entity and their associates Current quarter $A'000 6.1 Aggregate amount of payments to related parties and their associates included in item 1 16 6.2 Aggregate amount of payments to related parties and their associates included in item 2 9 Note: if any amounts are shown in items 6.1 or 6.2, your quarterly activity report must include a description of, and an explanation for, such payments Appendix 5B Mining exploration entity or oil and gas exploration entity quarterly cash flow report ASX Listing Rules Appendix 5B (01/12/19) Page 4 + See chapter 19 of the ASX Listing Rules for defined terms. 7. Financing facilities Note: the term “facility’ includes all forms of financing arrangements available to the entity. Add notes as necessary for an understanding of the sources of finance available to the entity. Total facility amount at quarter end $A’000 Amount drawn at quarter end $A’000 7.1 Loan facilities 7.2 Credit standby arrangements 7.3 Other (please specify) 7.4 Total financing facilities 7.5 Unused financing facilities available at quarter end 7.6 Include in the box below a description of each facility above, including the lender, interest rate, maturity date and whether it is secured or unsecured. If any additional financing facilities have been entered into or are proposed to be entered into after quarter end, include a note providing details of those facilities as well. 8. Estimated cash available for future operating activities $A’000 8.1 Net cash from / (used in) operating activities (Item 1.9) 65 8.2 Capitalised exploration & evaluation (Item 2.1(d)) (546) 8.3 Total relevant outgoings (Item 8.1 + Item 8.2) (481) 8.4 Cash and cash equivalents at quarter end (Item 4.6) 1,366 8.5 Unused finance facilities available at quarter end (Item 7.5) - 8.6 Total available funding (Item 8.4 + Item 8.5) 1,366 8.7 Estimated quarters of funding available (Item 8.6 divided by Item 8.3) 3 8.8 If Item 8.7 is less than 2 quarters, please provide answers to the following questions: 1. Does the entity expect that it will continue to have the current level of net operating cash flows for the time being and, if not, why not? Answer: 2. Has the entity taken any steps, or does it propose to take any steps, to raise further cash to fund its operations and, if so, what are those steps and how likely does it believe that they will be successful? Answer: 3. Does the entity expect to be able to continue its operations and to meet its business objectives and, if so, on what basis? Answer: Appendix 5B Mining exploration entity or oil and gas exploration entity quarterly cash flow report ASX Listing Rules Appendix 5B (01/12/19) Page 5 + See chapter 19 of the ASX Listing Rules for defined terms. Compliance statement 1 This statement has been prepared in accordance with accounting standards and policies which comply with Listing Rule 19.11A. 2 This statement gives a true and fair view of the matters disclosed. Date: 28 October 2025 Authorised by: By the Board Notes 1. This quarterly cash flow report and the accompanying activity report provide a basis for informing the market about the entity’s activities for the past quarter, how they have been financed and the effect this has had on its cash position. An entity that wishes to disclose additional information over and above the minimum required under the Listing Rules is encouraged to do so. 2. If this quarterly cash flow report has been prepared in accordance with Australian Accounting Standards, the definitions in, and provisions of, AASB 6: Exploration for and Evaluation of Mineral Resources and AASB 107: Statement of Cash Flows apply to this report. If this quarterly cash flow report has been prepared in accordance with other accounting standards agreed by ASX pursuant to Listing Rule 19.11A, the corresponding equivalent standards apply to this report. 3. Dividends received may be classified either as cash flows from operating activities or cash flows from investing activities, depending on the accounting policy of the entity. 4. If this report has been authorised for release to the market by your board of directors, you can insert here: “By the board”. If it has been authorised for release to the market by a committee of your board of directors, you can insert here: “By the [name of board committee – eg Audit and Risk Committee]”. If it has been authorised for release to the market by a disclosure committee, you can insert here: “By the Disclosure Committee”. 5. If this report has been authorised for release to the market by your board of directors and you wish to hold yourself out as complying with recommendation 4.2 of the ASX Corporate Governance Council’s Corporate Governance Principles and Recommendations, the board should have received a declaration from its CEO and CFO that, in their opinion, the financial records of the entity have been properly maintained, that this report complies with the appropriate accounting standards and gives a true and fair view of the cash flows of the entity, and that their opinion has been formed on the basis of a sound system of risk management and internal control which is operating effectively.