What is the estimated cash flow steady maintenance capex for the business over a multiyear period
g on. We've got relationships with 80 universities where we're not necessarily steering that technology work, but we are participating in it.
And as we see those technologies advance and look -- and get higher potential, have a higher potential of those things, we would look to try to bring into the portfolio. So we've got -- what I'd say, we've cast a pretty wide net around the technology space, recognizing that it's requiring some level of evolution, if not breakthroughs and technologies, for them to be successful. And so since you can't really plan for that, we kind of keep a finger on the pulse of a lot of different technologies with the intent then to, as they look more promising, kind of to bring them into the emerging and then commercial technology space. And so that's the work that this new group will be focused on.
And again, it's -- we'll complement what we're doing in the carbon capture and storage. We've got the biofuels work that we've been doing, and we've got the process technology work that we've been doing. And a lot of those things overlap with one another. Certainly -- and of course, that then also has hydrogen and the process technology work we're doing and the CCS work together have a lot of overlap with potential for hydrogen generation.
So I'd say that's the space that we tend to be working on from a technology standpoint. And then with respect to the spend, this is a long-term focus area for our facilities and businesses. And you can see from the progress we've made with reducing greenhouse gases, it's not something new. It's something we've been after year after year after year.
And those opportunities continue to present themselves. And I mentioned in my prepared remarks that with the new organization and the new processes that we've put in place, we've got more direct and better line of sight to those opportunities so that we can make sure they're getting funded and moving forward. And that's all built into our plans and it's built into our 2025 objectives that we've laid out.
Devin McDermott -- Morgan Stanley -- Analyst
Great. Thanks. Very helpful detail. It sounds like a lot of exciting opportunities.
My follow-up, hopefully, a quicker one here. As we think about just the capital spending range over the next several years, the $20 billion to $25 billion and contextualize that with the analysis that you had in the slides on the amount of cash flow contribution in 2025 from some of the new projects coming online, I was wondering if you could just help us pinpoint, what level of spend that you think is required in order to just hold cash flow across the business flat over a multiyear period, understanding it's kind of higher than the 2021 spend, somewhere within that $20 billion to $25 billion? Any way that you can fine-tune that estimate a little bit in terms of the maintenance capex, the whole cash flow steady?
Darren Woods -- Chairman of the Board and Chief Executive Officer
Yeah. Well, I think the way we tend to look at it is how do you maximize the value. And we don't have an objective of trying to hold volumes or any other metric. It comes back to if -- what are the projects that we have available to us, the investments, what are the returns that we think we can generate from those investments, what advantage do they have versus industry and within our own portfolio, how robust are they to the price environment.
So I would say that, as we look to build up our investment profile, it's understanding what the value of those investments are and then putting those in the context of the constraints that we're operating under to see which ones get funded and how we prioritize them. So I would say, in 2020, one of the things, given the impacts of coronavirus and draw on our balance sheet, is we really prioritized and focused on the highest value first. We've still got a really deep portfolio that we'll continue to advance as the circumstances allow and as the market allows, and that's how we're going to kind of go forward. And that range that we've given in the outer years is indicative of what we
g on. We've got relationships with 80 universities where we're not necessarily steering that technology work, but we are participating in it.
And as we see those technologies advance and look -- and get higher potential, have a higher potential of those things, we would look to try to bring into the portfolio. So we've got -- what I'd say, we've cast a pretty wide net around the technology space, recognizing that it's requiring some level of evolution, if not breakthroughs and technologies, for them to be successful. And so since you can't really plan for that, we kind of keep a finger on the pulse of a lot of different technologies with the intent then to, as they look more promising, kind of to bring them into the emerging and then commercial technology space. And so that's the work that this new group will be focused on.
And again, it's -- we'll complement what we're doing in the carbon capture and storage. We've got the biofuels work that we've been doing, and we've got the process technology work that we've been doing. And a lot of those things overlap with one another. Certainly -- and of course, that then also has hydrogen and the process technology work we're doing and the CCS work together have a lot of overlap with potential for hydrogen generation.
So I'd say that's the space that we tend to be working on from a technology standpoint. And then with respect to the spend, this is a long-term focus area for our facilities and businesses. And you can see from the progress we've made with reducing greenhouse gases, it's not something new. It's something we've been after year after year after year.
And those opportunities continue to present themselves. And I mentioned in my prepared remarks that with the new organization and the new processes that we've put in place, we've got more direct and better line of sight to those opportunities so that we can make sure they're getting funded and moving forward. And that's all built into our plans and it's built into our 2025 objectives that we've laid out.
Devin McDermott -- Morgan Stanley -- Analyst
Great. Thanks. Very helpful detail. It sounds like a lot of exciting opportunities.
 My follow-up, hopefully, a quicker one here. As we think about just the capital spending range over the next several years, the $20 billion to $25 billion and contextualize that with the analysis that you had in the slides on the amount of cash flow contribution in 2025 from some of the new projects coming online, I was wondering if you could just help us pinpoint, what level of spend that you think is required in order to just hold cash flow across the business flat over a multiyear period, understanding it's kind of higher than the 2021 spend, somewhere within that $20 billion to $25 billion? Any way that you can fine-tune that estimate a little bit in terms of the maintenance capex, the whole cash flow steady?
Darren Woods -- Chairman of the Board and Chief Executive Officer
Yeah. Well, I think the way we tend to look at it is how do you maximize the value. And we don't have an objective of trying to hold volumes or any other metric. It comes back to if -- what are the projects that we have available to us, the investments, what are the returns that we think we can generate from those investments, what advantage do they have versus industry and within our own portfolio, how robust are they to the price environment.
So I would say that, as we look to build up our investment profile, it's understanding what the value of those investments are and then putting those in the context of the constraints that we're operating under to see which ones get funded and how we prioritize them. So I would say, in 2020, one of the things, given the impacts of coronavirus and draw on our balance sheet, is we really prioritized and focused on the highest value first. We've still got a really deep portfolio that we'll continue to advance as the circumstances allow and as the market allows, and that's how we're going to kind of go forward. And that range that we've given in the outer years is indicative of what we