2026 Interim Results

ALWAYS DO BETTER

C O ML

Interim Results 2026

August 2026

The information contained in this presentation is intended solely for your personal reference. Inaddition, such information contains projections and forward-looking statements that rellect the Company'scurrent views with respect to future events and financial performance. These views are basedonassumptions subject to various risks. No assurance can be given that future events will occur, that projections will be achieved, or that the Company's assumptions are correct. Actual results maydiffermaterially from those projected. Past track record cannot be used as guidance for future performances.

Interim Results Review

2026H1

Brent crude

$86.6/bbl

77.9

63.3

130.0

88.5 86.0

Unit: US$ 100 million

59.7

31.4

The global utilization rate of jack-up has slightly declined, while the utilization rate of floater has increased significantly compared to the same period

Shell BP XOM Total CVX COP OXY

2025H1 2026H1

Oil Company CAPEX Comparison

Source: Bloomberg, as of August 2026

125

115

105

45

1月2日 2月2日 3月2日 4月2日 5月2日 6月2日

WTI Brent

2026H1 International Oil Price Trend

Source: Bloomberg, as of July 2026

International oil companies, boosted by strong cash flows from high oil prices, are focusing their investments on the upstream oil and gas sector

Global rig utilization rate

Source: S&P Global, as of July 2026

4

Operating Revenue

2% yoy 23.79 billion

Total Profit

4% yoy 2.68 billlion

Net Profit

3% yoy 2.13 billlion

Attributable net profit

2.01 billion 2% yoy

EBITDA 6.49 billion 0.2% yoy

EPS 0.42 yuan 2% yoy

5

All key indicators remain within a prudent range, and operational risks are under control

Profit levels continue to rise, while earnings returns remain stable

24.1 25.7 26.8

01 Asset-liability ratio 43.0 %

-2.9P yoy

Total labor

20.8 21.3

19.620.1 02

RMB1.15 million

17.1 15.9

Gross profit Net profit Attributable net profit

2024H1

2025H1

2026H1

03

04

productivity

R&D investment intensity

Operaating cash collection ratio

+5P yoy

2.6 %

-0.5P yoy

76.9 %

-6.4P yoy

6

COSL's equipment utilization rate remains at a high level, while its asset structure has been further optimized

Rig utilization rate

COSL

Vessel utilization rate

COSL

Source: S&P Global Report Source: Rystad report

Comparison of performance parameters for the same period

Drilling Company A

Drilling Company B

Revenue growth rate%

3.3 1.

5

3.9 -0.1 1.7 8.1 -18.7 2.5

Asset-liability ratio%

43.0 50.9 61.8 57.2 44.8 40.9

International peers: Schlumberger, Baker Hughes, Halliburton, Transocean, Valaris Data from various companies 7

Enhance resource supply and technical service support, striving to contribute professional value to offshore oil and gas exploration and development

Coordinate global deployment of large-scale equipment resources

Strengthen equipment O&M management and rig repair to keep the monthly average NPT low

The utilization rate of large-scale equipment stays above 90%

I4R research, production, implementation and reform research

18 technology product lines 79 core product clusters

6 technology brands

4 Landscapes: Technology, Products, IP, and Digitalization

8

Enhance resource supply and technical service support, striving to contribute professional value to offshore oil and gas exploration and development

Enhancing Professional Contribution through High-Quality Services

"Haijing" and "Haimai" joint operations have improved seismic acquisition efficiency by nearly 40%

The first-run success rate of high-end instruments such as "Drilog&Welleader" and "Haihong" exceeds 95%

Liner hanger operation success rate and wireline logging acceptance rate for cementing operations remain stable at 100%

Effectiveness rate of stimulation treatments, heavy oil thermal recovery, EOR and other production enhancement measures exceeds 97%

AI/digital empowerment - including well data processing and screening, intelligent cementing evaluation, etc. - drives service

Steadily Expanding Overseas Markets with a Global Vision

Business presence in over 40 countries and regions across Southeast Asia, the Middle East, Europe, the Americas, and Africa

Established strong partnerships with international oil companies including TotalEnergies, Equinor, and PTTEP

In-depth understanding of overseas client needs, with dedicated efforts to secure large-scale, long-term, high-value projects

quality and efficiency improvement 9

Main business segments ranked high among industry peers, with market size and market share still having room for growth

The global offshore drilling market was valued at US$32.18 billion in 2025

COSL's revenue from the drilling segment ranked 5th in the world in 2025

The global oilfield cementing market was worth US$8.271 billion in 2025

COSL's revenue from the cementing segment ranked 3rd in the world in 2025

The global oilfield drilling and completion fluids market was worth US$ 10.715 billion in 2025

COSL's revenue from drilling and completion fluids ranked 3rd in the world in 2025

Scale of global oilfield wireline logging was at US$13.418 billion in 2025

COSL's revenue from wireline logging ranked 4th in the world in 2025

The global geophysical acquisition and surveying services and equipment market was worth US$6.252 billion in 2025 COSL's revenue from the geophysical acquisition and surveying segment ranked 8th in the world in 2025

The global completion tools & services market was valued at US$9.804 billion in 2025

COSL's revenue from the well completion segment ranked

：

8th in the world in 2025 10

Source Spears&Associates Oilfield Market Report April 2026

Four major segments remained stable with positive momentum, with the Drilling Segment contributing the largest profit growth

Expanding in Brazilian waters with rising overall strength

Operating Revenue

billion

+240 million yoy

Unit: RMB

Operating profit

billion

+470 million yoy

NH 8 rose from 31st to 8th place in Petrobras' Sondopolis ranking, earning an official written commendation from Petrobras

Optimize project procedures to ensure efficient operational handover

The WZ11-6 Oilfield Development Project was completed 115 days ahead of the designed schedule, achieving an overall efficiency improvement of 40%

Drilling Platform Operating Days 9,906 9,741

2,130 2,372

2025H1 2026H1

jack-up semi-sub

Unit: days

11

Technology Segment builds independent and controllable core strengths, with rapid breakthroughs in application scenarios

Overseas technology footprint expanding steadily

Haihong completion system completed operations at Kingfisher oilfield

Operating Revenue

billion

+190 million yoy

Unit: RMB

Operating profit

billion

+40 million yoy

in Uganda, marking its first successful application in Africa HydraChem cementing business secured its first contract in Kuwait, achieving a breakthrough in the Middle East high-end market

First SAGD oil sands well service for PCC client in Canada, expanding business to non-system clients in North America

Full-size Xuanji high-end instruments successfully operated for PTTEP in Thailand, further driving regional market growth

Domestic technology applications set records, driving quality and efficiency gains.

Drilog&Welleader one-way crossing operation in Eastern South China Sea reached 5,306m, setting a new world record

HydraChem overcame ultra-long open-hole and high-inclination challenges in the Western South China Sea's first 8,000m-class extended-reach well, setting an 8,038m domestic offshore liner hanger record

First large-scale fracturing vessel HYSY696 operated in Bohai and East China Seas, achieving about 50% above expected production (Bohai) and 30%-35% efficiency gains (East China Sea)

H1 Technical Service Workload

Unit: well jobs

2025H1 2026H1 12

Marine Support Service

The MSS Segment is targeting high-value added markets and cultivating new drivers for profit growth

Expanding partnership networks and connecting with premium external customers.

Operating Revenue

billion

-10 million yoy

Unit: RMB

Operating profit

million

-80 million yoy

Through resource sharing and joint demand planning, a tripartite charter sharing agreement has been signed with internal and external clients, strengthening the marine support assurance system

Proactively promoting value-added services including offtake technology, marine support, and mooring buoy services

H1 Total Vessel Service Days

Offshore Engineering Support Vessel Services

Awarded a domestic engineering support vessel project, with day rates 80% higher than conventional operations and a contract value

41,510

43,814

Unit: vessel days

exceeding RMB 300 million

2025H1 2026H1

Standby Vessel AHTS PSV MPV Workover Support 13

The GAS segment boosts profitability;

In-house equipment continues rapid upgrades

Operating Revenue

Operating profit

High-Quality International Seismic Acquisition

At a seismic acquisition project in Indonesia, the company earned client operational and HSSE awards through

billion million

outstanding execution efficiency and robust safety

+40 million yoy

Unit: RMB

+50 million yoy

management, winning wide market acclaim for its overseas project management capabilities

H1 Geophysical Acquisition and Surveying Workload

Deployment of New Domestic "Haimai" Seismic Equipment

Achieved industrialization and service deployment of the "Haimai" ocean-bottom seismic equipment; established two OBN crews and one OBC crew

Targeted Bohai Sea exploration needs, executing seismic acquisition in 10 blocks over 3,200 km²

3,557

3,327

9,000

8,102

964

651

2D seismic acquisition (km) 3D seismic acquisition (km²) OBS acquisition (km²)

2025 H1 2026 H1 14

Technological innovation spearheaded industrial innovation, and new growth engines gained strong momentum

Achieved breakthroughs in piezoelectric ceramic vector geophones; trial-produced multi-component streamers; built a fully proprietary chain from sensing elements to cable manufacturing

Completed the first sea trial of the proprietary "Marine Seismic Exploration Satellite Positioning System" prototype, filling the company's capability gap in high-precision marine seismic satellite positioning equipment

Exploration

15

Technological innovation spearheaded industrial innovation, and new growth engines gained strong momentum

The "HydraChem" organic amine completion fluid system achieved its regional first successful application in Uganda and won TotalEnergies Safety Award

Awarded the second prize of the State Scientific and Technological Progress Award(2025) for key technologies and applications in geo-steering rotary steerable drilling systems

Drilling & Completion

The "ESCOOL"EFDT union in-situ core sampling and logging tool won the OTC Asia 2026 Award

16

Technological innovation spearheaded industrial innovation, and new growth engines gained strong momentum

Successfully applied the ultra-short radius flexible PDM drill in test wells and completed indoor performance testing for the self-developed hollow whipstock

Development & Production

Development & Production

Enabled the successful debut of HYSY 696 fracturing vessel in Penglai Oilfield via the 7-inch single-trip multi-zone frac-pack system, resolving productivity bottleneck in unconsolidated sandstone reservoirs

17

Full-chain digital integration across operations; empowering transformation with steady advancement

Empowering business efficiency through AI

Boosted acoustic data processing efficiency by over 3x via logging intelligent software

Improved seismic data acquisition efficiency by 95%, cutting data prep from 60 days to 3 days and processing projects from 180 days to 30 days

Achieved over 90% accuracy in intelligent cementing quality evaluation

Specialized software for direct value creation

Built a two-tier smart oilfield services operations center at across corporate and BU levels

Enabled real-time monitoring and dynamic resource allocation for global operations

Leveraged data models to achieve refined management and AI-assisted decision-making across the wellbore lifecycle

Generated direct economic value of over RMB 500,000 using integrated geological-reservoir platform (i-GRE)

Enhanced shore-based supply coordination, boosting inventory turnover efficiency by 43%, doubling warehouse space utilization, and saving RMB 900,000 in storage costs

18

Expanding and upgrading overseas markets, accelerating breakthroughs in technical services

Operating Revenue

Operating profit

76.1%

92.0% 91.5%

138

150

122

billion billion

+10.6% YoY +60.4% YoY

High-day-rate projects operating at high efficiency， high-value assets successfully commissioned

Maintained full utilization for high-day-rate platform operations in the Norwegian North Sea

Delivered high-quality operations for drilling projects in Brazil and Thailand

2024H1 2025H1 2026H1

Overseas project sites (count) Overseas platform utilization (%)

Breaking into new markets and business areas with technical services

Cementing operations and accessory technical support services in Kuwait

Coiled tubing nitrogen lift services in Iraqi oilfields

Offshore blended cement project for PTTEP in Thailand

19

Enhancing metric-driven management, achieving steady cost optimization

Sustained Improvement in Key Cost Metrics

Achieving cost control and efficiency enhancement in business operations

Total Cost per Unit Volume

Cost of Operating Ratio

83.2% 82.5% 81.5%

2024H1 2025H1 2026H1

57.8 58.0

57.5

Unit: RMB 10k

Administrative Expense Ratio

2.1% 2.1% 2.1%

2024H1 2025H1 2026H1

2024H1 2025H1 2026H1

20