How to check status of an order on BTC-e API?
It appears you are looking at "active orders" if you are seeing this status. As per BTC-e API documentation (found at: https://btc-e.com/api/documentation), you should be looking at trade history, which will show completed orders. Partial orders would show as individual trades on as the result e.g. if you place a sell/ask order 1 BTC @ $1000 and I were to place a buy/bid order of 0.1 BTC @ $1000 then you would see a trade of 0.1 BTC @ $1000 in your trade history, if I were to place the same order again against your 0.9 BTC remaining you would see two trades for 0.1 BTC @ $1000. This data is shown here for partial trades even if the order is still active.

Since the standard output is limited to the 1000 most recent transactions, I would recommend making use of the 'from' parameter when scraping trade data. You can increase the number of results but BTC-e will likely place a limit on how much data can be returned at some point in the future. You can also stagger API calls to get 1000 transactions at a time, however I would recommend putting this data in a table for better access.