Date: 201307
Local time of day: 0601-1200
Location: ZZZZ.Airport, FO
Flight conditions: VMC
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Aircraft component: Lubrication Oil
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: Pilot Flying; First Officer
Anomaly: Aircraft Equipment Problem Critical
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Inflight Shutdown; Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; General Declared Emergency
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Immediately after level off at FL290; requested cruise altitude; lower center DU popped up with a reverse video indication of Number 1 engine oil quantity low and decreasing eventually reaching zero. Referenced QRH procedure for 'ENGINE LOW OIL QUANTITY' which directs to monitor engine instruments. All other engine parameters were normal with oil pressure reading 43 PSI and oil temperature reading 103 degrees; which closely matched indications on Number 2 engine. Reviewed appropriate QRH procedures for low oil pressure and high oil temp and began discussion with First Officer as to what would be required if engine parameters degraded. Approximately 5 minutes after the initial low oil quantity reading the oil pressure began to decrease rapidly toward 3 psi. Performed QRH procedure for 'ENGINE LOW OIL PRESSURE' which directed Number 1 engine shutdown. First Officer remained pilot flying and took over radio responsibility and I performed checklist duties. Declared emergency and immediately requested descent to FL240 and return. Cleared direct and descent to 12;000 FT. Continued to review options with First Officer for other airport destinations and determined ZZZZ to be nearest suitable due to time; weather; services. First Officer continued flying aircraft and I began coordination with flight attendants and performed PA to passengers. Flight Attendant 4 was a speaker and relayed the PA in Spanish as we had a majority of passengers that did not speak English. We were then cleared for the arrival and ILS approach and we set the appropriate altitude in the MCP altitude selector. After resetting FMC cruise altitude; First Officer intercepted path at approximately 18;000 FT and began arrival and approach. Conditions were VMC and we had visual contact with the field at this time. I then notified Dispatch via ACARS and asked him to review our decision and other possible options. We concluded to proceed as planned. First Officer and I then began QRH 'ONE ENGINE INOPERATIVE' and 'EMERGENCY LANDING' checklists; review of QRH supplemental information; QRH Deferred items; approach and single engine procedures; and expected aircraft performance issues. First Officer was doing a superb job flying aircraft and as time was permitting I continued to review aircraft performance data and options for a plan B if the situation required a go around. I elected to exercise Captains Authority; 14 CFR 121.557; and have the First Officer continue the approach and landing. Flaps 15 landing [were] performed with max brakes. Aircraft touchdown at approximately 1;500 FT from threshold and stopped approximately 6;500 FT from threshold. Taxied to hard stand and deplaned passengers via air stairs.


Second narrative: [Report contained no additional information].


Synopsis: B737-800 flight crew experiences loss of engine oil quantity shortly after level off at FL290; followed by loss of oil pressure. The engine is shut down and the flight returns to the departure airport for landing.