A B757 ENG OIL QTY WENT TO ZERO CAUSING A FLUCTUATING OIL PRESSURE. THE CREW DECLARED AN EMER AND RETURNED TO LAND AT THE DEP ARPT.

Narrative

ALL OPS GOING AS PLANNED DURING CLBOUT FROM ZZZ IN VNAV CLB PWR HDG 270 DEGS UNTIL JUST AFTER 10000 FT AGL; I CYCLED THE NO SMOKING SIGN THEN NOTICED AND INFORMED THE PF WITH THE CTR AUTOPLT ENGAGED OF THE L ENG OIL PRESSURE FLUCTUATING WITH OIL QUANTITY ZERO. AS I GRABBED THE QRH I HAD THE PF REQUEST A LEVELOFF AND REQUEST A TURN TO RETURN TO ZZZ. WHEN WE REFED THE QRH ENG OIL PRESSURE 7.31 THE EICAS L ENG OIL PRESSURE MESSAGE ILLUMINATED SO WE ACCOMPLISHED THE ENG SHUTDOWN AS DIRECTED. I DECLARED AN EMER WITH ATC AND REQUESTED VISUAL TO THE LONGEST RWY THAT WE JUST TOOK OFF FROM 7-10 MINS EARLIER. I INFORMED THE FLT ATTENDANTS VIA INTERCOM OF OUR ENG-OUT SITUATION AND PLANNED RETURN THEN MADE A PA TO THE PAX ALSO INFORMING THEM OF OUR RETURNING TO ZZZ AS WELL AS ASSURING THEM THE B757 WAS VERY CAPABLE OF OPERATING SAFELY ON 1 ENG AND DIRECTED THEM TO FOLLOW FLT ATTENDANT INSTRUCTION NOW AND AFTER LNDG TO REMAIN SEATED WHILE GND CREWS INSPECTED OUR JET. WE ACCOMPLISHED THE DSCNT; AND APCH CHKLISTS ITEMS AND SET UP THE FMS AND CABIN ALT ON THE PRESSURIZATION PANEL FOR OUR RETURN. THE PF TURNED OVER FLYING DUTIES TO ME AND MADE SURE ALL CHKLISTS AND CLEANUP ITEMS WERE ACCOMPLISHED PROPERLY. AFTER THE SMOOTH OVERWT TOUCHDOWN WE EXITED THE RWY ON A VERY WIDE HIGH SPD AND HAD THE FIRE CHIEF INSPECT OUR ACFT BEFORE RETURNING TO GATE. THE PA AFTER LNDG TO INFORM THE PAX OF WHAT WAS GOING ON WAS FOLLOWED UP WITH AN INTERCOM CHAT WITH THE LEAD FLT ATTENDANT TO MAKE SURE ALL WAS WELL IN THE BACK BEFORE TAXIING TO OUR GATE.