Within the framework of the National Oil Corporation’s towards preserving the environment and reducing the negative environmental impact resulting from the production, operational and manufacturing processes in the oil and gas sector and achieving sustainable development, Zallaf Libya Oil and Gas Exploration and Production has conducted tests on the E4 oil well in the Erawin field NC-200. for the first time by using the (Closed Loop System), which does not include burning the extracted oil as previously known, therefore the application of the closed cycle method prevents the occurrence of air pollution and prevents the depletion of natural resources and their optimal use by following international specifications and standards by producing and separating Then, the crude oil transported during testing operations to the nearest surface production equipment through special tanks and equipment with international standard specifications.