Aug 2015

Disclaimer

2

The information contained in this presentation is intended solely for your personal

reference. In addition, such information contains projections and forward-looking

statements that reflect the Company’s current views with respect to future events

and financial performance. These views are based on assumptions 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 may differ materially from those projected. Past track record

cannot be used as guidance for future performances.

I.

II. Segment Review

I. Results Overview

3

III. Company Outlook

1. Market Environment

4

Proactive Responses with

Mid- to Long-Term Focus

Oil Price Plunged since 2H2014Brought Significant Changes to

OFS Industry

Oil companies started to cut budget, control capex and reevaluate project economics in low oil price environment

Intensified competition in global oilfield service industry led to reduction in utilization and day rates

COSL proactively responded to market challenges

Focus on market expansion and

client retention

Further strengthen cost control Continue to optimize capital structure

Promote R&D and application of self-

developed technologies

Source: ODS and Bloomberg, market data as of 5-Aug-2015.

0

20

40

60

80

100

120

140

160

2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

Brent WTI

(US$/bbl)

$45.15

$49.59

50%

60%

70%

80%

90%

100%

2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

Utilization – Semi-sub Utilization – Jack-up

73.1%

73.3%

2. Interim Financial Performance1

5

(RMB mm) 1H2015 1H2014 yoy % Change

Revenue 12,089.4 15,927.7 24.1%

Operating Profit2 1,260.9 5,029.1 74.9%

Operating Margin (Incl. Impairment) 10.4% 31.6% 21.2pp

Operating Margin (Excl. Impairment) 18.6% 32.6% 14.0pp

Net Profit 921.9 4,439.0 79.2%

Sufficient cash available³: RMB8.94bn

Further reduced leverage: debt-to-capital ratio of 38.6%; net debt-to-equity of 49.0%

US$1 billion senior unsecured notes issued in July 2015 to further enhance financial flexibility

(RMB mm) 1H2015 2014A yoy % Change

Total Assets 86,286.9 86,874.3 0.7%

Total Liabilities 40,322.5 39,552.2 1.9%

Shareholders’ Equity 45,964.3 47,322.1 2.9%

1. All above financial data are from the audited financial report prepared by the Company under HKFRS.

2. Includes RMB990mm impairment for individual assets in Norway and for goodwill.

3. Available Cash includes cash equivalents and available-for-sale financial assets.

3. Focus on Market Expansion and Client Retention

Key Progress of Overseas BusinessStrengthen Leading Position in China

Deepened strategic cooperation with CNOOC

Increased market share offshore China across all segments

Applied a series of self-developed technologies, with the

HTHP technology setting numerous operation records

COSL PROSPECTOR finished its first drilling service in

South China Sea

Won integrated drilling contract for Liwan 3-2-2

Stable composition of domestic and overseas revenues

— 63% from offshore China and 37% from overseas

More proactive business development strategy:

— Bid 266 projects in 1H2015, increasing by 40% yoy

Continued development of new markets and clients:

— Successfully obtained the contract in Indonesia from SAKA

— COSL GIFT won the bid for Chevron’s project in China

New operating support base in Mexico

HYSY981 completed its first overseas operations

HSYS937 finished drilling first overseas well

High-end logging technology entered Canada market

Provided deepwater marine services to SEA clients

Completed the first horizontal well acidizing service

through coiled tubing in Iraq

Enhance Business Development

6

Client Recognition for Quality Services

4. Promote R&D and Use of Self-Developed Technologies

Achieved breakthrough in on-site application, with

operational experience at 1,500m of water depth

Have the ability to provide drilling fluids and cementing

services at water depth up to 2,500m

动画to come

The first company in China and the fourth company

worldwide possessing both technologies

Accomplished onshore and offshore testing and the first

offshore joint operation

Maximize oil production under fixed budget

Improve capabilities in deepwater and HTHP wells

Help clients reduce project cost through new technology

Meet and exceed HSE requirements

Meet Customer Needs through

Innovation

Deepwater Drilling Fluids and Cementing

7

Contract Value from New

Technologies

Environmentally friendly

well completion fluids

(~RMB40mm)

Deepwater technology

(~RMB380mm)HTHP technology

(~RMB310mm)

Composite salt-

gypsum bed

formation

(~RMB260mm) RMB

980mm

Welleader® and Drilog®

1. Contract value refers to the cumulative value created by new technologies.

5. Further Strengthen Cost Control

Annual variable cost reduction target: RMB1.5bn

Realized variable cost reduction in 1H2015: RMB1.08bn

Reduce material cost: Enhance management

Reduce repair and maintenance expense: Conduct

more maintenance works using in-house resources

Reduce subcontractor expense: Reduce

subcontracting work and price

Reduce rental expense: Accelerate the

commercialization of self-developed technologies

Reduce other operating expense: Control

administrative expense, adjust compensation structure

and retire old equipment

Other operating

expenses (27%)

Rental (4%)Repair and

maintenance (12%)

Subcontractor

expense (12%)

Material (45%)

RMB

1.08bn

8

Breakdown of Cost Reduction in 1HSolid Progress in Cost Reduction

Cost Reduction Measures

6. Maintain Industry Leading Position

1. Fixed asset turnover in 1H2015 = revenue in 1H2015 / the average of beginning and ending balance of fixed asset.

Further Improved Safety Management

Excellent safety management ensures smooth operations: record-low OSHA indicator of 0.07 in 1H2015

Leading utilization rates among industry peers during low oil price environment: rig utilization rate of 80% and

vessel utilization rate of 90% in 1H2015

Higher fixed asset turnover and lower finance cost than comparable offshore drillers

9

0.45

0.220.27

0.290.32

0.25

0.260.23

0.20

0.19

0.24

0.18

0.08

0.07

02 03 04 05 06 07 08 09 10 11 12 13 14 1H15

43%38% 36% 35%

29% 27%

Transocean Diamond Ensco Rowan Noble

Fixed Asset Turnover1

7. Awards and Recognition from Capital Market

Constituent stock of Hang Seng (China A)

Corporate Sustainability Index; and constituent

stock of Hang Seng Corporate Sustainability

Benchmark Index

2015 All-Asia Executive Team

by Institutional Investor

— The Company once again

won the “Most Honored

Company” award

“Best Investor Relations Company (China)”

from Corporate Governance Asia

2015 All-Asia Executive Team

by Institutional Investor

— …and 6 sub-category awards

including the oil & gas sector

“Best Investor Relations”

10

11

II. Segment Review

I. Results Overview

III. Company Outlook

Segment Performance

Geophysical andSurveying

Drilling

Services

33 jack-ups

11 semi-subs

2 accommodation

rigs

5 module rigs

Marine

Support

74 self-owned utility

vessels

Additional 49

utility vessels under

management

Well

Services

Logging, drilling and

completion fluids,

directional drilling,

cementing,

completion, well

workover, EOR, and

other services

7 seismic vessels (38

cables)

6 surveying vessels

2 ocean bottom cable

teams

Drilling (54%) Well Services (28%)

Geophysical

and Surveying

(6%)

Marine

Support

(12%)

RMB

12.1bn

1H2015 Operating Profit

The Company’s business volume and price across segments were impacted by the low oil prices with different degrees

In 1H2015, Well Services and Marine Support in total contributed over 40% of revenue and operating profits

12

1H2015 Revenue

1.3bn

Drilling（60%） Well Services （28%）

Geophysical

and Surveying

（-5%）

Marine

Support

（17%）

22 years

19 years

16 years

2002 2008 1H 2015

Decreasing Average Age of Drilling Fleet

Calendar Day

Utilization RateDaily Income

Drilling Services

Operating Days

Optimized Fleet to Enhance Competitiveness

44 rigs covering water depth up to 10,000 feet1

Declining average age of rig fleet

More than half of the rigs < 10 years

1H2015 operating days reduced 348 days yoy

— +487 days due to new equipment

— -Additional 1,098 standby days

— +263 days due to less maintenance

Average daily income decreased 15.6% yoy

1H revenue of RMB6.56bn, down by 23.8% yoy

1H operating profit of RMB760mm, down 79.0%

yoy

— Down 51.7% yoy if excl. impairment loss

Reduction of Utilization Rates and Day Rates

13

More than half < 10

years old

1H14 1H15

Jack-ups Semi-subs

(5.3)%

1,779 1,352

4,814 4,893

1H14 1H15

91.0%

80.0%

1. As of June 30, 2015

1H14 1H15

(15.6)%

18.015.2

(US$10,000/day)

Well Services

Further enhance inter-segment synergies – IPM1 projects to drive business volume of Well Services

— Newly signed COSL PROSPECTOR project

— Smooth on-going execution of the IPM project in Missan, Iraq

Using self-developed new technologies to enhance competitiveness in high-end well service market

— Breakthroughs in wireline logging, LWD, directional drilling and EGPS integrated processing and interpretation system

— Application of HTHP technologies, creating economic value of RMB310mm

Leverage Synergies from IPM Projects and Self-Developed Technologies to Drive Business Volume

Reduction of Business Volume and Service Price

Segment revenue was RMB3.3bn for 1H 2015, representing a 17.4% decrease yoy

Segment operating profit was RMB350mm for 1H2015, with an operating profit margin of 10.7%

141. IPM stands for Integrated Project Management

安全生产，优质服务，市场需求稳定

Operating Days of Self-Owned Vessels

Marine Support Services

Calendar Day Utilization Rate of

Self-Owned Vessels

Deployed 5 vessels to SEA in 1H2015

Calendar day utilization rate of self-owned vessels was 90.5%, largely remaining stable

Self-owned utility vessels operated for 11,892 days, up 251 days yoy, driven by 3 new vessels

1H2015 revenue of RMB1.48bn, down by 14.4% yoy

1H2015 operating profit of RMB210mm, up by 152.9% yoy

Optimize Resource Allocation to Ensure Stable Utilization Rate

Further Adjust Fleet Structure to Enhance Competitiveness

15

11,641 11,892

1H14 1H15

2.2% 93.0% 90.5%

1H14 1H15

(Days)

Geophysical and Surveying Services

Enhance Competitiveness through Service Quality and Technology

Milestone: Completed the first seabed cone penetration test in South China Sea with water depth of 1,389 meters

Successfully conducted the first trial operation of the self-developed “Haitu” towing integrated navigation system

Deployed 2 seismic vessels to overseas market

2D collection down by 1,356 km yoy due to retirement of 2 seismic vessels

2D processing of 9,032 km, up by 123.9% yoy

3D collection declined significantly yoy due to soft demand

1H2015 revenue of RMB750mm, down 53.2% yoy

Segment operating loss of RMB60mm, down 115.3% yoy

Underperformance due to Capex Reduction by Upstream Companies

3D Workload2D Workload

16

12,215

10,859

4,034

9,032

1H14

1H15

2D Collection (km) 2D Processing (km) 2 2

17,085

8,258

11,305

7,565

1H14

1H15

3D Collection (km ) 3D Processing (km )

17

II. Segment Review

I. Results Overview

III. Company Outlook

Source: Company public disclosure

* Jinzhou 9-3 oil field adjustment and Kenli 10-1 oil field have been put into operation and other new projects are being carried out as planned.

Closely Follow the Demand of Core Customer

Opportunities from CNOOC Ltd.

Jinzhou 9-3 oil field adjustment*

Kenli 10-1 oil field*

Luda 10-1 oil field adjustment

Bozhong 28/34 oil fields

adjustment

Dongfang 1-1 gas field Phase I

adjustment

Weizhou 11-4N oil field Phase II

Weizhou 12-2 oil field joint

development

Production Target of CNOOC Ltd. CNOOC Ltd.’s New Discoveries in China

Long-Term Strategic Partnership with CNOOC Ltd. Key Customers

Strategic Cooperation Balanced DevelopmentMarket-Oriented

18

New Projects of

CNOOC Ltd. in 2015

Maintain close communication with core customers, thoroughly exploring potential business opportunities to enhance leading

position offshore China

7 new projects with CNOOC Ltd. in 1H2015, providing strong support to backlog

Continue to strengthen close cooperation with other NOCs and large international oil companies

(mmboe)

12

13

11

10

14

2010 2011 2012 2013 2014

62%67% 67% 66%

38%33%

33% 34%

433

~509 ~513

2014 2015 T 2016 T 2017 T

Domestic International

475-495

Domestic Market

Actively develop new service models to

help customers lower cost and improve

profitability

Ensure leading position and market share in

the offshore China market

Overseas Market

Develop new business operating models to

roll out more customized solutions

Consolidate and expand overseas market

and promote integrated services

Enhance Market Share in China Strategic Markets

Canada (high-end well logging technology)

India (well service equipment)

Middle East

Mexico

Southeast Asia, etc.

19

…

~

~ ~

~95%

60% 60%

100%

Drilling Services Well Services Marine Support Geophysicaland Surveying

Future Market Development Strategies

Cost Advantages by Integrated Synergies

Equipment + Technology enhances flexibility

Equipment

Segment

Technology

Segment

Continued optimization of

equipment structure

Outstanding work efficiency

Excellent capability of

equipment management

Maintain leading utilization

Joint marine operation

with self-developed

Welleader® and Drilog®

systems

Key technological

break-through in ELIS

imaging system

New Opportunities in Well Services

20

Stable production in mature fields

Enhanced oil recovery

Offshore heavy oil technologies

Complex-well drilling and completion

technologies

Marginal oilfield technologies

Offshore

HTHP wells and ultra deepwater

services (up to 10,000 ft)

Deepwater anti-shallow-flow well

cementation technology, filler low-

density cement slurry technology, and

deepwater water-based drilling fluid and

constant-rheology synthetic-based

drilling fluid technology

Deep-water

Canada, India, Mexico…Overseas

Business

Capture Cross-Segment Synergies and New Opportunities

Jack-ups Semi-subs Module Rigs Accommodation Rigs

Operating

AreaName

2015 2016

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Domestic

21 Jack-ups 在中国海域作业的平台将在年底洽谈下一

4 Semi-subs 一年度合同

NH6/NH7/NH8/NH9 澳洲作业 平台坞修

Overseas

COSL1/2/3/4/7 持续至2017年

CONFIDENCE 持续至2017年

HYSY936

HUNTER/BOSS

GIFT

STRIKE 持续至2017年

FORCE 持续至2017年

CRAFT

SUPERIOR

HYSY937

SEEKER

PROMOTOR 持续至2017年

INNOVATOR 持续至2017年

PIONEER

RIGMAR

RIVAL

21

2016 contract will be discussed in the end of 2015

8 years + 8 years contract

Till Jun. 2017

Till Aug. 2017

2016 contract will be discussed in the end of 2015

Till 2018 2H

Till Aug. 2018

8 years + 8 years contract

Backlog Updates for Key Equipment

Note: Unlabeled international rigs are under bidding process or negotiation. POWER is on warm stack position since the beginning of 2015.

8.78.1

6.5-7.5

2013 2014 2015B

Projects under construction

New projects

80%

20%

Effective Cost Control and Prudent Capital Expenditure

2015 Variable Cost Reduction Target

Target for 2H2015

(~420mm)

Completed in 1H2015

(~1.08bn )

1-year

Target of

1.5bn

Capital Expenditure

Dividend Policy

According to the Company’s AoA, annual dividend should

not be less than 20% of total net profit for the same year on

condition that the Company can maintain normal operation

and sustained development and the year’s profit and

accumulated undistributed profit are positive

Dividend distribution policy will remain unchanged

22

Seize the opportunity of declining equipment manufacturing

cost to invest in mid- to long-term strategic equipment

Implement a more prudent capex plan and investments will

be used mainly for projects under construction

Achieved 72% of annual cost reduction target in 1H

Continue to reduce costs and promote efficiency in 2H

(RMB bn)

Sound Financial Structure Brings More Flexibility

Source: Bloomberg and rating reports

1. Total capital = total debt + total equity (including non-controlling interests).

Total debt / total capital1Company Moody’s S&P Fitch

Div

ers

ifie

d M

ajo

rs

Schlumberger Aa3 (Stable) AA- (Stable) -

Halliburton A2 (Stable) A (Watch Neg) A- (Stable)

Baker Hughes A2 (Stable) A (Watch Neg) -

Weatherford Baa3 (Neg) BBB- (Neg) BBB- (Neg)

COSL A3 (Stable) A- (Stable) A (Stable)

Off

sh

ore

Dri

llers

Diamond A3 (Stable) BBB+ (Stable) -

Ensco Baa1 (Stable) BBB+ (Stable) -

Noble Baa2 (Stable) BBB (Stable) -

Rowan Baa3 (Stable) BBB- (Stable) -

Transocean Ba1 (Stable) BB+ (Stable) BBB- (Neg)

Seadrill Ba3 (Neg) BB- (Neg) -

Sound Financial Structure

“The ratings outlook is stable, reflecting

Moody's expectation that COSL (1) will

manage well its capital expenditures

according to market conditions; (2) maintain

a strong financial profile through industry

cycles; (3) will secure long-term service

contracts for its rigs; and (4) will continue to

benefit from CNOOC Group's capital

expenditures and production in offshore

China ”

“We expect COSL's total debt to remain

stable as its operating cash flows will

likely cover most of its capital

expenditure and other cash needs…We

assess COSL's liquidity as "strong"

because we expect the Company's

sources of liquidity to exceed uses by

more than 1.5x over the next 12-18

months”

23

50.9%45.3%

36.4% 38.9%

2012 2013 2014 1H15

Summary

Oil prices will be fluctuating at a low level in the short-term

Capex reduction of E&P companies brought profound impact to global OFS industry

Oil and gas will continue to play an important role in global energy structure in the medium-to long-

term

24

Further leverage

comparative advantage

and strive to become

the world’s leading

integrated oilfield

service provider

Continue to enhance

core competitiveness

through active market

expansion,

commercialization of

self-developed

technologies and

improvement of service

quality

Stick to prudent

financial policy and

keep improving cost

efficiency to navigate

through challenging

industry environment

25