While jet demand reached post-pandemic highs in the fourth quarter, it's still roughly 15% below 2019 levels as business travel remains suppressed, but we expect to see recovery in that this year as well.
Since our last earnings call at the beginning of November, we've repurchased approximately $3 billion of shares.
That puts us at approximately 55% complete on our initial $10 billion share repurchase program.
Further reinforcing our commitment to return capital to shareholders, we obtained board approval for an additional $5 billion in share repurchase authorization.
This brings our total outstanding authorization to approximately $9.5 billion.
We expect MPC will have approximately $1.7 billion in capital expenditures, with approximately 50% of the $1.3 billion growth capital for our Martinez refinery conversion.
Total costs for the Martinez refinery conversion is estimated at $1.2 billion.
Approximately $300 million has been spent to date, $700 million for 2022 and $200 million for 2023.
On the portfolio, we completed the Speedway sale, receiving $17.2 billion of proceeds from that transaction and securing the 15-year fuel supply agreement with 7-Eleven.
And this year, MPLX produced exceptionally strong cash flow, which provided $2.2 billion of contributions to MPC.
As we look at cost reduction, what began as a $1.5 billion cost-reduction initiative is being embraced by the organization and now a low-cost culture is becoming embedded in how we conduct our business.
In March of 2021, we started up the Beatrice pretreatment facility, which processes about 3,000 barrels a day of advantaged feedstock for the Dickinson renewable diesel plan.
In December, we closed on a joint venture with ADM, which will provide approximately 5,000 barrels a day of logistically advantaged feedstock for Dickinson when the new soybean crush plant comes online in 2023.
And in January of this year, we successfully started up our Cincinnati pretreatment facility, which will process about 2,000 barrels per day for our Dickinson renewable diesel plant.
Adjusted earnings exclude $132 million of pre-tax charges related to make-whole premiums for the $2.1 billion in senior notes we redeemed in December.
Additionally, the adjustments include an incremental $112 million of tax expense, which adjusts all results to a 24% tax rate.
Beginning with our first quarter 2022 results, we will be reporting our effective tax rate on an actual basis and will no longer adjust our actual results to a 24% tax rate.
Adjusted EBITDA was $2.8 billion for the quarter, which is approximately $400 million higher from the prior quarter.
Cash from operations, excluding working capital, was $2 billion, which is an increase of almost $300 million from the prior quarter.
Finally, during the quarter, we returned $354 million to shareholders through dividend payments and approximately $2.7 billion in share repurchases.
In the three months since our last earnings call, we have repurchased approximately $3 billion of shares.
Since the beginning of 2020, we have been able to maintain roughly $1.5 billion of cost reductions that have been taken out of the company's total cost.
Refining has been lowered by approximately $1 billion.
Our refining operating costs in 2020 began at $6 per barrel.
While we were able to finish 2021 with a full year operating cost per barrel that was $5.
Additionally, midstream was reduced by $400 million and corporate cost by about $100 million.
However, regardless of the margin environment, our EBITDA is directly improved by this $1.5 billion.
MPC's 2022 capital investment plan totals approximately $1.7 billion.
As we continue to focus on strict capital discipline, our overall spend remains approximately 30% below 2019 spending levels.
Sustaining capital is approximately 20% of capital spend, underpinning our commitment to safety and environmental performance.
Of the remaining 80% for growth, approximately 50% of this $1.3 billion supports the conversion of Martinez into a renewable fuels facility.
Adjusted EBITDA was higher quarter over quarter, driven primarily by a $354 million increase from Refining & Marketing.
The adjustment column reflects $132 million of pre-tax charges for make-whole premiums for debt redemption during the quarter, which has also been excluded from the interest column.
The business reported continued improvement from last quarter with adjusted EBITDA of $1.5 billion.
Fourth quarter EBITDA increased $354 million when compared to the third quarter of 2021.
Gulf Coast production increased by 14%, recovering from storm-related downtime last quarter, and solid margin per barrel increased 31% due to higher export sales and higher sales of light product inventory.
The West Coast margin per barrel increased 40% associated with increased demand and refinery outages.
Utilization was 94% for the quarter, slightly improved from the third quarter.
Additionally, we saw natural gas prices softened during the quarter, coming off highs in the $5 to $6 range and ending in the $3 to $4 range.
Operating cash flow was approximately $2 billion in the quarter.
This excludes changes in working capital and also excludes the cash we received for our CARES tax refund in the quarter, which was approximately $1.6 billion source of cash and is included in the income tax part of the chart.
Working capital was an approximate $1.3 billion source of cash this quarter, driven primarily by reduction in crude and product inventory.
As we announced on last quarter's call, MPC redeemed $2.1 billion in senior notes in December.
Under income taxes, we received approximately $1.6 billion of our CARES tax refund in the fourth quarter.
We also used about $300 million to offset against our Speedway tax obligation.
There is about $60 million of the refund remaining, which we expect in the first half of 2022.
We paid approximately $1.2 billion for our Speedway income tax obligation.
All that remains is about $50 million of state and local taxes.
With respect to capital return during the quarter, MPC returned $354 million to shareholders through our dividend and repurchased approximately $2.7 billion worth of shares.
At the end of the quarter, MPC had approximately $10.8 billion in cash and short-term investments.
MPC's investment plan, excluding MPLX, totals approximately $1.7 billion.
The plan includes $1.6 billion for Refining & Marketing segment, of which approximately $300 million or roughly 20% is related to maintenance and regulatory compliance spending.
Our growth capital plan is approximately $1.3 billion, split between renewables and ongoing projects.
Also included is approximately $100 million of corporate spending to support activities we believe will enhance our ability to lower future costs and capture commercial value.
Their plan includes approximately $700 million of growth capital, $140 million of maintenance capital, and $60 million for the repayment of their share of the Bakken Pipeline joint venture's debt due in 2022.
Since our last earnings call at the beginning of November, we have repurchased approximately $3 billion of company shares.
This puts us at approximately 55% complete on our initial $10 billion repurchase program commitment, leaving approximately $4.5 billion remaining.
We remain committed to complete the $10 billion program by the end of 2022.
As part of our long-term commitment to return capital, we announced an incremental $5 billion share repurchase authorization today, increasing our recent repurchase authorizations to $15 billion.
MPC ended the year with approximately $10.8 billion of cash and short-term investments.
But longer term, we believe that we will need to maintain about $1 billion of cash on the balance sheet.
Currently, we have a $5 billion bank revolver that is undrawn.
At year end\, MPC's gross debt-to-capital ratio is 21% and our long-term gross debt-to-capital target is approximately 30%.
After the recent redemption in December, our current structural debt is approximately $6.5 billion, and we do not have any maturities until 2024.
We expect total throughput volumes of roughly 2.9 million barrels per day.
Planned turnaround costs are projected to be approximately $155 million in the first quarter.
Total operating costs are projected to be $5.10 per barrel for the quarter.
Distribution costs are expected to be approximately $1.3 billion for the quarter.
Corporate costs are expected to be $170 million.

Summary:
Further reinforcing our commitment to return capital to shareholders, we obtained board approval for an additional $5 billion in share repurchase authorization.
We expect MPC will have approximately $1.7 billion in capital expenditures, with approximately 50% of the $1.3 billion growth capital for our Martinez refinery conversion.
While we were able to finish 2021 with a full year operating cost per barrel that was $5.
MPC's 2022 capital investment plan totals approximately $1.7 billion.
Additionally, we saw natural gas prices softened during the quarter, coming off highs in the $5 to $6 range and ending in the $3 to $4 range.
Under income taxes, we received approximately $1.6 billion of our CARES tax refund in the fourth quarter.
MPC's investment plan, excluding MPLX, totals approximately $1.7 billion.
As part of our long-term commitment to return capital, we announced an incremental $5 billion share repurchase authorization today, increasing our recent repurchase authorizations to $15 billion.
Currently, we have a $5 billion bank revolver that is undrawn.