Waste vegetable oil (WVO) Grease from the nearest fryer which is filtered ('cuz chunks of potatoes and fish don't so much lube the chambers) and used in modified diesel engines, or converted to biodiesel through the process of transesterification and used in any ol' diesel car. Weather Window The part of the year when the weather is suitable for operations which cannot be carried out in adverse sea and wind states, e.g. pipeline or platform installation. Well A hole drilled in the earth for the purpose of (1) finding or producing crude oil or natural gas; or (2) producing services related to the production of crude or natural gas. Wildcat Speculative exploration well drilled in search of a new oil or gas accumulation. Wireline Wire or cable used for downhole operations. Usually either steel wire used to lower instruments into a well or electric for recording instruments. Workover Re-entry into a completed well for modification or repair work. WOW Waiting on weather.