Captain reported the loss of oil pressure and oil quantity on the right engine in cruise. With thrust reduced on the affected engine; a drift down and diversion was initiated; and a safe landing was made at the diversion airport.

Narrative

Diversion summary; out XA:01Z Off XA:24Z Crew change @ XF50Z Approximately 10 minutes later I was called in crew rest. Regarding an engine problem Immediate return to cockpit -quick situational brief Engine oil quantity R zero Engine oil pressure R decreasing First Officer (FO) PNF already established comms with Dispatch awaiting link FO Pilot Flying (PF) FO and I reviewed the engine oil pressure R checklist in the flight manual. Then immediately reviewed the QRC drift down procedure Very shortly there after... Engine oil pressure R Master caution and Engine oil pressure indication. Performed checklist. Reduce thrust to approximately 20%- EICAS message Extinguished. Gently increased power to determine the master caution threshold. Master caution EICAS returned at approximately 25% thrust Re-reduced throttle to 20% - EICAS again extinguished. Transitioned Immediately thereafter to QRC Driftdown procedure. Driftdown procedure accomplished with heading direct to diversion airport ZZZZ. FO return from crew rest to cockpit. Expedited descent from cruise altitude to below 250 Precautionary for potential traffic de-confliction. Fuel endurance was not an issue. Eased decent once below 25 kts. to below SE (Single Engine) max cruise altitude eventually leveling @ 20K In the decent master caution EICAS returned with R ENG thrust now at idle Performed the remainder of the Engine oil pressure R checklist requiring full engine shut down (shut at occurred at at approximately XH01z to landing at ZZZZ). CRUISED AT 20 kts.below max SE Cruise altitude at +/- 290 kts. Further Coordination with Dispatch/ Maintenance Control [Priority handling requested] and Initial Clearance direct ZZZZ1 with ZZZZ2. (Further clearances were achieved via ZZZZZ and HF with ZZZZ/and finally ZZZZ Tower Controller via VHF issued decent and approach for ILS Runway XX) Ran DIVERSION CHECKLIST Study of ZZZZ Airport info/NOTAMS/TERRAIN and LANDING PREFOMANCE #s [Brief] with pursuer ILS Runway XX Flaps 20 max auto brakes Approx 420;000 lbs landing wt. Elected not to dump fuel to lower landing weight in case of ZZZZ issues. Uneventful landing. Taxied on Runway XY exit Taxiway 1 to apron. Passengers were deplaned and initially taken into the Terminal. Thereafter all crew were Deplaned and proceeded to hotel accommodations FO and I stayed with Aircraft to assist with Passengers/freight/baggage issues and eventual Aircraft repositioning via push tug to the Runway XX Debriefed Maintenance Control via cell phone on eng indications and checklists preformed. After ensuring that all passengers had been Accounted for and were being accommodated FO and I Departed airport at +/-XZ:40.