China Oilfield Services
Chinese petroleum services company
China Oilfield Services (COSL) is an oilfield services company. It is a majority owned subsidiary of Chinese state owned company CNOOC Group. It also has a listed sister company in Hong Kong, CNOOC Limited.
China Oilfield Services usually purchases off shore vessels (OSVs) and operates them in Southeast Asia, the Middle East and Central Asia in off shore projects of CNOOC. It also operates in Indonesia, Malaysia and the Caspian Sea.
Overseas
COSL's overseas revenue surged 133% year on year in the first half of 2015 to 209.8 million yuan, driven by demand for its services in Indonesia, West Africa and the Middle East.
COSL had an office in Kuala Lumpur, Malaysia briefly in the early 2000s when it had its first western Vice President, Alan Good, a British born Oilman who helped launch the company internationally and pushed for further growth in the international sector.
COSL also maintains an office in Houston, TX as COSL America.
Stock
Globally, the number of listed players in the oilfield services sector is just over 100, with a combined market capitalisation of about US$250 billion. The top five account for 40% of the industry's market capitalisation. The two largest companies in this sector are Schlumberger with a 2007 year-end market cap of US$117.6 billion and Halliburton with a 2007-year end market cap of US$33.4 billion.
This brief starts where responsible research should: with the source description of “China Oilfield Services” as chinese petroleum services company. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the history & society register because the source frames it as chinese petroleum services company. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Contemporary correspondence, administrative files and participant testimony can test how later narratives organized the event or institution. The source revision retrieved here is dated Jun 15, 2026. The linked authority identifier is Q5099833. 2 of 2 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 2015 and 2007.
Official terminology may obscure informal participation, dissent or communities documented only indirectly. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Compare institutional narratives with records created by participants and affected communities. Dates and formal titles are useful anchors, but not substitutes for context.
- Event chronology
- Institutional context
- Locating named record creators
Contemporary correspondence, government or organizational records, oral histories and cited historical scholarship.
Three-step research path
- Establish the record: confirm the title “China Oilfield Services”, its source revision and the description used here.
- Expand the search: follow China Oilfield Services primary sources, China Oilfield Services archive and China research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “China Oilfield Services”?
- Who created the surviving record, and for what administrative purpose?
- Which voices are present, absent or mediated by the institution?
Search terms from this dossier
This entry incorporates text from “China Oilfield Services” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.