HOUSTON, March 27 (Reuters) - Global energy companies are getting back to basics and focusing on the hunt for new sources of oil and gas, executives declared at the CERAWeek conference in Houston this week, ending years of underinvestment in exploration. In recent years, the shale revolution in the U.S. promised abundant, flexible supply, while growth in ​renewable resources like wind and solar raised doubts about long‑term oil demand. Many oil and gas drillers chose to funnel profits to dividends and share buybacks instead of exploration. Now, production in the Permian Basin ‌in the U.S. is expected to plateau while energy demand keeps growing. Oil and gas producers are racing to plug gaps in their reserves over the next decade as each year of production depletes existing fields. The U.S.-Israeli war on Iran is heightening the importance of finding new resources. Executives at the conference warned that supply shortages could continue for longer than expected, making new discoveries potentially more critical. Rebuilding reserves through acquisitions rather than exploration - a popular strategy - will be challenging after the number of massive deals in recent years, energy executives and experts said at ​CERAWeek and in interviews. This puts the focus back on geography and geology. "Five years ago nobody was talking about the replacement, right? It was forgotten. But we need to start thinking about how we are going ​to replace the current production in the coming years," Francisco Gea, Repsol's executive managing director of exploration and production, said during the conference. The oil and gas industry has been ⁠replacing less than 25% of its annual production, drastically down from the heyday of exploration from the 1950s to the 1970s, when it replaced production over five times annually, Occidental CEO Vicki Hollub said during a conference panel. TECHNOLOGY TO THE ​RESCUE, AND THE NEED FOR SPEED Technology is helping oil majors move faster than ever, slashing the time between making a discovery and drilling first oil, executives said. Norway's Equinor   (EQNR.OL)  opens new tab   is targeting an average exploration timeline from discovery to first oil of two to ​three years, down from five to six years, CEO Anders Opedal told Reuters in an interview. “We’re working differently with suppliers, different internal processes, approval processes,” Opedal said. “I will not now personally approve one project at a time. I will approve six to eight in a batch.” Exxon Mobil   (XOM.N)  opens new tab   is also focusing on speed. Before even deciding to enter an exploration block, the company factors in how quickly it believes it can achieve first oil production, John Ardill, Exxon’s head of global exploration, said during a panel. The company is aiming to grow oil and ​gas production to 5.5 million barrels per day by 2030. BP   (BP.L)  opens new tab   has focused on building up inventory of discovered resources and development opportunities to keep projects moving toward final investment decisions, Gordon Birrell, executive vice president of production and operations, told ​Reuters in an interview. “We're very disciplined in which projects we invest capital in, and which we bring forward first,” he said. In 2025, BP announced 12 discoveries, including the Bumerangue find in Brazil and others in Egypt and the U.S. Gulf. It also reported ‌discoveries in Namibia ⁠and Angola through its Azule Energy joint venture with Eni   (ENI.MI)  opens new tab . BREAKTHROUGH DISCOVERIES ARE NEEDED In 2015, Exxon discovered oil in Guyana, estimated to hold at least 11 billion barrels of recoverable resource and widely regarded as the most recent significant discovery. Other majors have felt pressure to find their own breakthroughs to make up for an expected production shortage in the next decade. Shell   expects   an output shortfall of 350,000 to 800,000 barrels of oil equivalent per day over the next decade due to maturing fields unable to meet targets, Reuters has reported, citing the company and analysts. The British major is looking at oil or gas projects in Venezuela and could give the green light to one or two by year-end if the fiscal and ​legal situation in the country allows, CEO Wael Sawan said ​this week. At the end of 2024, Chevron’s total reserves ⁠fell to their lowest point in at least 10 years. The company closed its acquisition of Hess last year, which boosted reserves. CEO Mike Wirth has said   reviving exploration   is a focus. ORGANIC GROWTH IS A GOAL Companies stepped back from exploration over the last 25 years, and used M&A as a tool to grow, said Claudio Descalzi, CEO of Italian oil company Eni, which ​industry experts praised this week for its exploration strategies. Eni plans to develop over 850,000 bpd of organic growth over the next five years, he said. “Companies are realizing ​this huge reserves replacement gap is ⁠not one that they can M&A their way out of,” Adam Blythe, partner at Bracewell, said this month. “While new acquisitions can help in part, many of the most obvious and impactful opportunities have already happened.” Some governments are taking steps to cooperate to help boost exploration. In Angola, a top producer in Africa, licensing rounds that used to take 18 months to two years are now being completed in under six months, said Alcides Andrade, an executive board member of the National Petroleum Gas and ⁠Biofuels Agency in ​Angola. The country plans to further reduce that to about three months, he said. Oil executives frequently say exploration is risky, and amounts to an ​art rather than a precise science.   Brazil   and   Namibia   are two examples of countries where oil majors have struggled to make discoveries. "Everybody is refocusing to try and do more exploration again," said OMV   (OMVV.VI)  opens new tab   CEO Alfred Stern in an interview with Reuters this week. "There's always a balance then in organic exploration and ​inorganic and the difference is really the timing, how long it takes to get to production there."