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China Oilfield Services Limited — Investor Relations & Filings

Ticker · 601808 ISIN · CNE100000759 LEI · 529900J4X53VL8QQW675 Shanghai Stock Exchange Mining and quarrying
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Filings indexed 1,203 across all filing types
Latest filing 2026-05-22 Declaration of Voting R…
Country CN China
Listing Shanghai Stock Exchange 601808

About China Oilfield Services Limited

https://www.cosl.com.cn/english/

China Oilfield Services Limited provides integrated solutions across the lifecycle of offshore oil and gas exploration, development, and production. The company operates through four core segments: drilling services, well services, marine support, and geophysical and surveying services. Its extensive asset portfolio includes a modern fleet of jack-up and semi-submersible drilling rigs, offshore support vessels, and seismic survey ships. Technical expertise encompasses logging-while-drilling, rotary steerable systems, cementing, and well completion. COSL serves a global client base, operating in diverse offshore regions including the Asia-Pacific, Middle East, and the Americas. The company leverages proprietary research and development to enhance operational efficiency and safety in challenging marine environments. Its integrated service model provides a competitive advantage by offering comprehensive, end-to-end technical support for offshore energy projects.

Recent filings

Filing Released Lang Actions
中海油服2025年年度股东会、2026年第一次A股类别股东会及2026年第一次H股类别股东会决议公告
Declaration of Voting Results & Voting Rights Announcements Classification · 95% confidence The document is the formal resolution announcement of the company’s 2025 Annual General Meeting and the 2026 first A-share and H-share class meetings, including detailed voting results on each agenda item. This corresponds to an official declaration of shareholder vote outcomes at general meetings, matching the Declaration of Voting Results & Voting Rights Announcements (DVA) category.
2026-05-22 Chinese
北京市天元律师事务所关于中海油田服务股份有限公司2025年年度股东会、2026年第一次A股类别股东会及2026年第一次H股类别股东会的法律意见
Regulatory Filings Classification · 85% confidence The document is a legal opinion letter issued by Tian Yuan Law Firm concerning the legality of the procedures, convening, attendance, voting, and results of the 2025 Annual General Meeting and related class meetings. It does not itself provide financial statements (so it is not an Annual Report, Interim Report, or Earnings Release), nor is it a presentation, proxy solicitation, or voting results announcement in the company’s own voice. Instead, it is a regulatory/legal certification required by the stock exchange filings. Under the classification rules, this falls under general Regulatory Filings (RNS) as a compliance document and legal opinion accompanying the shareholder meeting notice.
2026-05-22 Chinese
中海油服H股公告-2025年度报告
Annual Report Classification · 100% confidence The document is titled '2025 年度报告' which translates to '2025 Annual Report'. It contains comprehensive company information including company overview, business performance, financial summary, chairman's statement, management discussion and analysis, corporate governance report, board report, independent auditor's report, and financial statements prepared according to Hong Kong Financial Reporting Standards. The document length is 15,000 characters, indicating a full detailed report rather than a brief announcement. It includes detailed financial data, business segment performance, and strategic outlook, all typical of an official annual report. Therefore, this document fits the definition of an Annual Report (10-K). FY 2025
2026-04-14 Chinese
中海油服2025年度独立董事述职报告（赵丽娟）
Board/Management Information Classification · 95% confidence The document is titled as an "Independent Director's Work Report for 2025" for 中海油田服务股份有限公司 (CNOOC Oilfield Services Co., Ltd.). It details the independent director's background, attendance at board and committee meetings, communication with auditors, oversight of financial reports, and governance activities during the year 2025. The content focuses on the director's duties, governance, and supervisory roles rather than presenting financial statements or audit opinions. It is a detailed management/governance-related report rather than a financial report or audit report. Therefore, it fits best under the category of Board/Management Information (MANG), which includes announcements or reports related to board members and senior management activities. The document length (5367 characters) and detailed content support this classification rather than a brief announcement or a full annual report.
2026-03-24 Chinese
中海油服对会计师事务所2025年度履职情况评估的报告
Audit Report / Information Classification · 95% confidence The document is titled as an evaluation report on the performance of the accounting firms (Ernst & Young Hua Ming and Ernst & Young Hong Kong) for the year 2025. It discusses the audit firms' qualifications, the audit process, and the company's assessment of their performance in auditing the 2025 financial statements. It includes details about the audit engagement, audit opinions, and internal control audits. This is a standalone audit-related report focusing on the audit firms' performance and their audit results, not the full annual report itself. The document length is about 2107 characters, which is relatively short but contains substantive audit evaluation content, not just an announcement or certification. Therefore, it fits best under the category of Audit Report / Information (AR). FY 2025
2026-03-24 Chinese
中海油服2025年度独立董事述职报告（郭琳广）
Board/Management Information Classification · 95% confidence The document is titled as an "Independent Director's Work Report" for the year 2025 by an independent director of the company. It details the director's background, attendance at meetings, exercise of duties, communication with auditors and shareholders, review of financial reports, internal controls, and governance activities. It is a detailed report on the independent director's activities and oversight during the fiscal year, focusing on governance and compliance rather than financial results or audit opinions alone. This type of document fits best under Board/Management Information (MANG) as it relates to management and board-level reporting on governance and director activities. It is not an annual report, audit report, or earnings release, nor is it a proxy or voting announcement. The length and content confirm it is a substantive report, not a brief announcement or certification. Therefore, the classification is MANG with high confidence.
2026-03-24 Chinese

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