That would represent an oversubscription of more than three times the size of the bond, if Aramco sticks to its plan to issue around $10 billion in the debt sale, due this week.
State-owned Saudi Aramco met investors last week in a global bond roadshow ahead of the issue. The bond is expected to attract demand from both emerging markets and investment-grade buyers as Aramco's status as the world's largest oil company would put its bonds in the same league as debt issued by independent international oil majors like Exxon and Shell.
Speaking at an event in Riyadh, Falih said the issue will close on Wednesday and that he believed demand for the bond was "north of" $30 billion.
Aramco, which declined to comment, will open the bond books later on Monday, sources told Reuters.
Aramco has said the bonds may range from three to 30 years in maturity. Sergey Dergachev, a manager of EM corporate debt at Germany-based Union Investment, said he expected the bond to have four tranches of three, five, 10 and 30 years and to range between $10 billion and $15 billion in size.
He said he expects demand for the paper to reach $45 billion-$50 billion, as its different maturities will attract a wide range of investors from different regions.
"The short part of the curve, three and five years, will be strongly bid by locals and some Asians. The 30-year will be heavily in demand by U.S. and Taiwanese investors."
Pension funds and insurance companies in the US and Taiwan are traditionally interested in investing in long-term securities to match the long duration of their own capital.
Lured by Aramco's vast profits - which were nearly three times those of Apple last year - a large number of investors are willing to buy the bonds even if they offers less than Saudi government debt, sources familiar with the matter told Reuters.
"The success of this bond issue will be the litmus test and a crucial precursor for the anticipated Aramco IPO within the next two years," said Salah Shamma, head of investment, MENA equities, at Franklin Templeton.
Aramco last year postponed a planned initial public offering to 2021.
The bond issue, announced last week, follows on the heels of Aramco's agreement to buy a 70% stake in petrochemicals firm Saudi Basic Industries from Saudi Arabia's Public Investment Fund (PIF) in a deal worth $69.1 billion.
Al-Falih said on Monday he hopes Aramco's SABIC acquisition will be completed within six months.
In a company presentation last week, however, the company said the deal will close in 2020.
The transaction will give PIF firepower to proceed with its plans to create jobs and diversify the largest Arab economy beyond oil exports.
Falih said in addition to SABIC, there will be other assets, "non-strategic assets", that PIF may exit.
"I think the vision of the PIF goes way beyond the $69 billion that Saudi Aramco will provide to the PIF, which is very bold, it's global and domestic at the same time," he said.
PIF has invested in ride-hailing firm Uber Technologies and in electric carmakers Lucid Motors and Tesla. "So don't be surprised, just as bold as they were in entering some of these investments, that they do exit," said Falih.
PIF will be looking globally to acquire emerging companies in emerging industries "to create value for them, but at the same time to leverage those acquisitions and investments for the benefit of the kingdom's strategy," he said.
This story has been published from a wire agency feed without modifications to the text.