* Indonesia's first-half oil lifting at 771,000 bpd
* Mobil Cepu overtakes Chevron as top crude producer
* Tangguh is biggest gas producer, edging out Mahakam (Recasts, adds quotes, context)
By Wilda Asmarini
JAKARTA, July 6 (Reuters) - Indonesia did not meet its oil and gas output and investment targets in the first half of 2018, following project delays, the country's upstream oil and gas regulator (SKKMigas) said on Friday.
The biggest oil producer in Southeast Asia, Indonesia's crude oil lifting reached 771,000 barrels per day (bpd) in the six months to June 30, below a full-year target of 800,000 bpd, SKKMigas data showed, and below the 2017 figure of 803,800 bpd.
Over the same period, Indonesia's gas lifting was at 1.15 million barrels of oil equivalent per day (boepd), missing the full-year goal of 1.2 million boepd.
Lifting refers to oil or gas output that is ready for shipping and differs to production.
Investment in Indonesia's upstream oil and gas sector reached $3.9 billion in the first half, just over a quarter of the 2018 target of $14.2 billion, the regulator said.
"Realised investment remained low not because investments were cancelled, but because project schedules were pushed back," SKKMigas chief Amien Sunaryadi told reporters.
Exxon Mobil Corp unit Mobil Cepu Ltd, operator of the Banyu Urip oilfield in the Cepu block, became Indonesia's biggest crude oil producer in the first half, overtaking Chevron unit Chevron Pacific Indonesia, operator of the Rokan block.
Mobil Cepu's crude lifting reached 209,922 bpd, above its full-year target of 205,000 bpd. Chevron Pacific Indonesia's crude lifting hit 207,148 bpd, below a goal of 213,551 bpd.
Chevron was expected to submit revisions of development plans for its Gendalo and Gehem hub projects next week, Sunaryadi said. "If there are no delays it will be onstream as planned," he said.
The Gendalo hub is expected to come onstream in 2022 and Gehem in 2023, with a combined capacity of 1.1 billion cubic feet of natural gas and 47,000 barrels of condensate per day.
For gas, lifting by BP unit BP Berau Ltd, operator of the Tangguh natural gas project, climbed to 1,049 million cubic feet per day (MMCFD), ahead of its full-year target of 1 billion cubic feet per day.
That made Tangguh Indonesia's biggest source of natural gas, overtaking the Mahakam block, whose output shrank.
Pertamina unit Pertamina Hulu Mahakam, which this year took over Mahakam from French major Total and Japan's Inpex , saw gas lifting of 916 MMCFD, well below the 1,255 MMCFD realised in 2017.
"Wells that were drilled did not produce results that had been hoped for, that had been predicted earlier," Sunaryadi said, referring to Mahakam.
"It wasn't because of the transition to Pertamina - that was no problem," he added. (Reporting by Wilda Asmarini Writing by Fergus Jensen Editing by Richard Pullin and Manolo Serapio Jr.)