We delivered adjusted earnings of $1.73 per share and nearly $1.1 billion of free cash flow, repeating the record level of free cash flow we generated last quarter.
Our performance clearly proves the power of doubling our reinvestment hurdle rate, double premium requires investments to earn a minimum of 60% direct after-tax rate of return using flat commodity prices of $40 oil and $2.50 natural gas.
In the first half of this year, we reduced our long-term debt by $750 million and demonstrated our priority to returning cash, significant cash to shareholders with a commitment of $1.5 billion in regular and special dividends.
We also closed on several low-cost, high potential bolt-on acquisitions in the Delaware Basin over the last 12 months.
Year-to-date, we have committed $2.3 billion to debt reduction in dividends, which is slightly more than the $2.1 billion of free cash flow we've generated.
While we announced our shift to the double-premium investment standard at the start of this year, the shift has been underway since 2016 when we first established our premium investment standard of 30% minimum direct after-tax rate of return using a conservative price deck of $40 oil and $2.50 natural gas for the life of the well.
In the three years that followed, our premium drilling program drove a 45% increase in earnings per share, a 40% increase in ROCE in an oil price environment nearly 40% lower compared to the three-year period prior to premium.
In addition, premium enabled this remarkable step change in our financial performance, while reinvesting just 78% of our discretionary cash flow on average, resulting in $4.6 billion of cumulative free cash flow.
The impact from doubling our investment hurdle rate from 30% to 60% using the same conservative premium price deck is now positioning EOG for a similar step change to our well productivity and costs, boosting returns, capital efficiency, and cash flow.
This year, we are averaging less than $7 per barrel of oil equivalent finding cost.
Looking back over the last four quarters, EOG has earned a 12% return on capital employed with oil averaging $52.
We are well on our way to earning double-digit ROCE at less than $50 oil, and it begins with disciplined reinvestment in high-return double-premium drilling.
While EOG has 11,500 premium locations, approximately 5,700 are double-premium wells located across each of our core assets.
In the past 12 months, through eight deals, we have added over 25,000 acres in the Delaware Basin through opportunistic bolt-on acquisitions at an approximate cost of $2,500 per acre.
Exploration and bolt-on acquisitions are focused on improving the quality of the inventory by targeting returns in excess of the 60% after-tax rate of return hurdle.
Once again, we exceeded our oil production target, producing slightly more than the high end of our guidance, driven by strong well results.
We have already exceeded our targeted 5% well cost reduction in the first half of 2021.
We now expect that our average well cost will be more than 7% lower than last year.
As a reminder, this is in addition to the 15% well cost savings achieved in 2020.
Average drilling days are down 11%, and the feet of lateral completed in a single day increased more than 15%.
As a reminder, 65% of our well costs are locked in for the year, and the remaining costs we are actively working down through operational efficiencies.
We reduced our greenhouse gas intensity rate 8% in 2020, driven by sustainable reductions to our flaring intensity.
Achieving these targets is the first step on the path toward our ambition of net-zero emissions by 2040.
For companywide operations in the U.S., water supplied by reuse sources last year increased to 46%, reducing freshwater to less than one-fifth of the total water used.
We are starting to fill in the pieces on the road map to get to net-zero by 2040.
Earlier this year, we announced our net-zero ambition for our Scope 1 and Scope 2 GHG emissions by 2040.
As a result, since 2017, we have reduced our GHG intensity rate 20%, our methane emissions percentage by 80% and our flaring intensity rate by more than 50%.
Our wellhead gas capture rate was 99.6% in 2020 and roll-out of additional closed-loop gas capture systems will help capture more of the remaining 0.4%.
Over the past 18 months, we have deployed capital into several fuel substitution projects to power compressors used for natural gas pipeline operations and natural gas artificial lift.
The EOG culture has embraced our 2040 net zero ambition, and we are focusing our efforts to minimize our carbon footprint as quickly as possible.

Summary:
We delivered adjusted earnings of $1.73 per share and nearly $1.1 billion of free cash flow, repeating the record level of free cash flow we generated last quarter.
Once again, we exceeded our oil production target, producing slightly more than the high end of our guidance, driven by strong well results.
We have already exceeded our targeted 5% well cost reduction in the first half of 2021.