b'KOSMOS ENERGY LTD.Notes to Consolidated Financial Statements (Continued)7. Equity Method Investments (Continued)PeriodNovember 28,Year Ended 2017 throughDecember 31, December 31,2018 2017(In thousands)Revenues and other income:Oil and gas revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $721,299 $54,615Other income . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (477) 294Total revenues and other income . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 720,822 54,909Costs and expenses:Oil and gas production. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147,685 15,509Depletion and depreciation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126,983 10,738Other expenses, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 429 (19)Total costs and expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275,097 26,228Income before income taxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445,725 28,681Income tax expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156,981 6,588Net income. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $288,744 $22,093Kosmos share of net income . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $144,372 $11,046Basis difference amortization(1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71,491 5,812Equity in earningsKTIPI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 72,881 $ 5,234(1) The basis difference, which is associated with oil and gas properties and subject to amortization,has been allocated to the Ceiba Field and Okume Complex. We amortize the basis difference usingthe unit-of-production method.When evaluating our equity method investments for impairment, we review our ability to recoverthe carrying amount of such investments or the entitys ability to sustain earnings that justify itscarrying amount. As of December 31, 2018, we determined that we had the ability to recover thecarrying amount of our equity method investment in KTIPI. As such, no impairment has beenrecorded. Our initial investment has been increased for our net share of equity in earnings as adjustedfor our basis differential and reduced by cash dividends received. During the year ended December 31,2018, we received $257.5 million of cash dividends from KTIPI.With an effective date of January 1, 2019, our outstanding shares in KTIPI were transferred toTrident in exchange for a 40.375% undivided interest in the Ceiba Field and Okume Complex. As aresult, our interest in the Ceiba Field and Okume Complex will be accounted for under theproportionate consolidation method of accounting going forward.127'