b'KOSMOS ENERGY LTD.Notes to Consolidated Financial Statements (Continued)5. Property and EquipmentProperty and equipment is stated at cost and consisted of the following:December 31,2018 2017(In thousands)Oil and gas properties:Proved properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 2,773,276 $ 1,653,616Unproved properties . . . . . . . . . . . . . . . . . . . . . . . . . 759,472 465,109Support equipment and facilities . . . . . . . . . . . . . . . . . 1,463,213 1,427,054Total oil and gas properties . . . . . . . . . . . . . . . . . . . 4,995,961 3,545,779Accumulated depletion . . . . . . . . . . . . . . . . . . . . . . . . (1,551,097) (1,234,806)Oil and gas properties, net . . . . . . . . . . . . . . . . . . . . . . . 3,444,864 2,310,973Other property . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51,987 39,405Accumulated depreciation. . . . . . . . . . . . . . . . . . . . . . (37,150) (32,550)Other property, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14,837 6,855Property and equipment, net . . . . . . . . . . . . . . . . . . . . . $ 3,459,701 $ 2,317,828We recorded depletion expense of $316.3 million, $244.9 million and $131.5 million anddepreciation expense of $4.6 million, $3.4 million and $3.5 million for the years ended December 31,2018, 2017 and 2016, respectively.6. Suspended Well CostsThe Company capitalizes exploratory well costs as unproved properties within oil and gasproperties until a determination is made that the well has either found proved reserves or is impaired.If proved reserves are found, the capitalized exploratory well costs are reclassified to proved properties.Well costs are charged to exploration expense if the exploratory well is determined to be impaired.The following table reflects the Companys capitalized exploratory well costs on completed wells asof and during the years ended December 31, 2018, 2017 and 2016. The table excludes $65.6 million,$43.2 million and $2.4 million in costs that were capitalized and subsequently expensed during the sameyear for the years ended December 31, 2018, 2017 and 2016, respectively. During 2017, the exploratory123'