b'KOSMOS ENERGY LTD.Notes to Consolidated Financial Statements (Continued)3. Acquisitions and Divestitures (Continued)and has a 55% participating interest, Cairn has a 20% participating interest, and ONHYM holds a 25%carried interest in the block through the exploration period. In November 2017, we provided to ourco-venturers a notice of withdrawal from the Boujdour Maritime block offshore Western Sahara andtransferred its participating interest and operatorship to ONHYM. Certain transition services are beingprovided to ONHYM as part of the handover of operatorship. In order to complete our obligationsunder the petroleum contract, we funded the remainder of the seismic program.In September 2016, we entered into an agreement by which BP agreed to pay Kosmos $30 millionin lieu of drilling an exploration well and assigned its 45% participating interest in the EssaouiraOffshore Block back to us, and the Moroccan government issued joint ministerial orders approving theassignment in October 2016, making it effective. After giving effect to the assignment, our participatinginterest is 75% in the Essaouria Offshore block and we remain the operator. The $30 million paymentwas received from BP in January 2017. In August 2018, we provided to the Office National DesHydrocarbures et des Mines (ONHYM) a notice to abandon the Essaouira Offshore block, locatedoffshore Morocco, at the end of the current exploration phase (November 2018).In October 2016, we entered into a petroleum contract covering Block C6 with the IslamicRepublic of Mauritania. As a result of a subsequent farm-out we have a 28% participating interest andprovide technical exploration services to BP, the operator. The Mauritanian national oil company,Societe Mauritanienne des Hydrocarbures et de Patrimoine Minier (SMHPM), currently has a 10%carried participating interest during the exploration period. Block C6 currently comprises approximately1.1 million acres (4,300 square kilometers), with a first exploration period of four years from theeffective date (October 28, 2016). The first exploration phase includes a 2,000 square kilometer 3Dseismic requirement.In December 2016, Kosmos closed a farm-out agreement with a subsidiary of Galp EnergiaSGPS S.A. (Galp) to farm-out a 20% non-operated stake of the Companys interest in Blocks 5, 11,and 12 offshore Sao Tome and Principe. Based on the terms of the agreement, Galp paid aproportionate share of Kosmos past costs in the form of a partial carry on the 3D seismic survey whichwas completed in August 2017.4. Joint Interest Billings and Related Party ReceivablesThe Companys joint interest billings consist of receivables from partners with interests in commonoil and gas properties operated by the Company. Joint interest billings are classified on the face of theconsolidated balance sheets as current and long-term receivables based on when collection is expectedto occur.In 2014, the Ghana National Petroleum Corporation (GNPC) notified us and our block partnersof its request for the contractor group to pay GNPCs 5% share of the Tweneboa, Enyenra andNtomme (TEN) development costs. The block partners are being reimbursed for such costs plusinterest out of a portion of GNPCs TEN production revenues. As of December 31, 2018 and 2017, thecurrent portion of the joint interest billing receivables due from GNPC for the TEN fields developmentcosts were $14.0 million and $15.2 million, respectively, and the long-term portion were $14.0 millionand $31.6 million.The Companys related party receivables consists primarily of receivables from Trident who, untilJanuary 2019, owned a 50% interest in KTIPI. As of December 31, 2018 the balance due from Tridentconsists of $5.6 million related to joint interest billings for the exploration blocks and Kosmos supportof KTIPI operations.122'