In the upstream sector, exploration and production activities, or E&P, are categorized as either exploration activities or production activities. Exploration activities include geologic and geophysical operations aimed at surveying a particular land area or a portion of the seabed and determining the possibility of locating economically viable underground oil and gas deposits. Obtaining leases and permissions from relevant parties, such as the government or landowners, is another relevant activity. Alternatively, production activities involve developing oil or gas reserves into productive oil or gas fields, as well as recovering or extracting those reserves. Project closure activities begin once all reserves have been effectively extracted. These activities include drilling, infrastructure engineering, and construction projects. The activities include plugging and abandoning of fields and wells, as well as reassessing the project.