Overcurrent protection of electrical systems in Oil & Gas industry is a priority for the security of the system; electrical failures involve great economic losses. The electrical protections are configured according to studies performed under the premise of a radial system. Problems in setting and coordination of those protections arise, when various power sources are connected to supply the demand. In this paper the authors present a methodology that utilizes digital protective relays to solve the lack of coordination in overcurrent protection when the supply grid and on-site generation are used in the oilfield electric distribution system. Using ETAP®, an overcurrent protection study was performed on an oilfield electric system. As a result, an adaptive overcurrent protection scheme was elaborated and proved to fulfill the requirements of electrical protection without regard the power source to which the oilfield is connected.