b'KOSMOS ENERGY LTD.Notes to Consolidated Financial Statements (Continued)3. Acquisitions and Divestitures (Continued)15% carried interest in the blocks through exploration. The petroleum contracts cover approximately13,600 square kilometers, with a first exploration period of four years from the effective date (March2018). The exploration periods can be extended an additional four years at our election subject tofulfilling specific work obligations. The first exploration period work programs include a 13,500 squarekilometer 3D seismic acquisition requirement across the two blocks.In June 2018, we completed a farm-in agreement with a subsidiary of Ophir Energy plc (Ophir)for Block EG-24, offshore Equatorial Guinea, whereby we acquired a 40% non-operated participatinginterest. As part of the agreement, we reimbursed a portion of Ophirs previously incurred explorationcosts and will fully carry Ophirs share of the costs of a planned 3D seismic program as well as pay adisproportionate share of the well commitment should we enter the second exploration sub-period. Thepetroleum contract covers approximately 3,500 square kilometers, with a first exploration period ofthree years from the effective date (March 2018) which can be extended up to four additional years atour election subject to fulfilling specific work obligations. The first exploration period work programincludes a 3,000 square kilometer 3D seismic acquisition requirement which was completed inNovember 2018. In January 2019, we entered into an agreement to acquire Ophirs remaining interestin the block, subject to customary governmental approvals, which will result in Kosmos owning an 80%interest in Block EG-24.In September 2018, we completed the acquisition of DGE, a deepwater company operating in theU.S. Gulf of Mexico, from First Reserve Corporation and other shareholders for a total considerationof $1.275 billion, comprised of $952.6 million in cash, $307.9 million in Kosmos common stock and$14.9 million of transaction related costs. We funded the cash portion of the purchase price using cashon hand and drawings under our existing credit facilities. We also received $200.0 million of additionalfirm commitments under the Facility, which provided further liquidity to the Company. The DGEacquisition was accounted for under the asset acquisition method and the purchase price allocation isshown below. The purchase price allocation was based on the estimated relative fair value ofidentifiable assets acquired and liabilities assumed.The estimated fair value measurements of oil and gas assets acquired and asset retirementobligations liabilities assumed are based on inputs that are not observable in the market and thereforerepresent Level 3 inputs. The fair value of oil and gas properties and asset retirement obligations weremeasured using the discounted cash flow technique of valuation. Significant inputs to the valuation ofoil and gas properties include estimates of: (i) reserves, (ii) future operating and development costs,118'