The Hamra Basin Province encompasses approximately 244,100 square kilometers (94,250 square miles) and is entirely within Libya. One composite total petroleum system (TPS) was defined for this assessment; it extends from Libya westward into adjacent parts of Algeria and southern Tunisia. The Hamra Basin part of the TPS was subdivided into four assessment units for the purpose of resource assessment. The assessment units cover only 172,390 square kilometers of the Hamra Basin Province; the remaining area has little potential for undiscovered petroleum resources because of the absence of petroleum source rocks.
Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean volumes of 784 million barrels of crude oil, 4,748 billion cubic feet of natural gas, and 381 million barrels of natural gas liquids in the Hamra Basin of northwestern Libya. Most of the undiscovered crude oil and natural gas are interpreted to be in deeper parts of the Hamra Basin.