* Oil majors' output set to rise 9 pct by 2018 - analysts
* Production will gain modestly after 2020, mostly for gas
* Capex cuts to moderate, but not stop, growth
* GRAPHIC: Oil majors' output growth http://tmsnrt.rs/2c0eSev
By Ron Bousso
LONDON, Sept 5 (Reuters) - Never mind the drop in crudeprices, huge spending cuts and thousands of job losses - theworld's top oil and gas companies are set to produce more thanever for some time.
While top oil companies struggle with slumping revenuesfollowing a more than halving of prices since mid-2014 afteryears of spectacular growth, their production has persistentlygrown as projects sanctioned earlier in the decade come on line.
Overall production at the world's seven biggest oil and gascompanies is set to rise by around 9 percent between 2015 and2018, according to analysts' estimates.
With an expected recovery in prices, the increasedproduction should boost cash flow and secure generous dividendpayouts, which had forced companies to double borrowingthroughout the downturn.
"There are a lot of projects coming on stream over the nextthree years that will support cash flow and ultimatelydividend," Barclays analyst Lydia Rainforth said.
And despite a drop in new project approvals, companies havethroughout the downturn cleared a number of mammoth undertakingssuch as Statoil's Johan Sverdrop oilfield off Norwayand Eni's Zohr gas development off the Egyptian coast.
Others opted to acquire new production, such as Royal DutchShell, which bought smaller rival BG Group for $54billion this year, and Exxon Mobil through investmentsin Papua New Guinea and Mozambique.
Shell is expected to see the strongest growth among itspeers over the next two years at 8 percent, according to BMOCapital Markets.
Production is unlikely to drop after 2020, and could postmodest growth as companies continue to bring projects onstream,albeit at a slower pace, BMO analyst Brendan Warn said.
French oil major Total, for example, plans toclear three major projects by 2018 - the Libra offshore oilfieldin Brazil, the Uganda onshore project and the Papua LNG project- that will begin production after 2020.
"We won't see 5 to 10 percent growth that we've seen fromcompanies in recent years. It will be closer to 1 or 2 percent,"Warn said.
SUSTAINABLE
Capital spending, or capex, for the sector is set to dropfrom a record $220 billion in 2013 to around $140 billion in2017 before modestly recovering, according to Barclays.
But companies have learnt to do more with the money afterslashing expenditure and tens of thousands of jobs, while thecost of services such as rig hiring dropped sharply throughoutthe downturn.
"2017 is the sweet spot for integrated companies. It tooktwo to three years to adjust to the drop in oil prices, and alot of the efficiencies introduced in recent years will rollinto 2017, when projects kick in and free cash flow willimprove," Rainforth said.
The resilience is mostly due to new gas projects coming onstream as companies shift towards the less polluting hydrocarbonthat is expected increasingly to displace oil demand in comingdecades.
The slower pace of project development after a decade ofrapid growth that was accompanied by soaring costs will helpcompanies, Warn said.
"That is much more sustainable for a major that will reducethe number of large capex projects."
(Reporting by Ron Bousso; Editing by Dale Hudson)