Howdy!
OnePetro.org is a wonderful search engine for those who would like to reach many papers/articles at one place. Here is the list of organizations with technical documents in OnePetro.
American Petroleum Institute (API)
American Rock Mechanics Association (ARMA)
American Society of Safety Engineers (ASSE)
International Petroleum Conference (IPTC)
International Society for Rock Mechanics (ISRM)
Offshore Technology Conference (OTC)
NACE International (corrosion engineers)
National Energy Technology Laboratory (NETL)
Petroleum Society of Canada (PETSOC)
Pipeline Simulation Interest Group (PSIG)
Society of Petroleum Engineers (SPE)
Society of Petroleum Evaluation Engineers (SPEE)
Society of Petrophysicists and Well Log Analysts (SPWLA)
The Society of Underwater Technology (SUT)
World Petroleum Council (WPC)
In addition to these organizations, I still think that it would be even more comprehensive search engine if OnePetro could add one of the leading professional societies into its portfolio; AAPG (American Association of Petroleum Geologists).
