Adjusted EBITDA in the second quarter topped $117 million.
Free cash flow in the quarter approached $70 million after funding capex of 77 million.
Net debt improved by 58 million in the second quarter, driven by our free cash flow.
First, our leading daily margin performance in the Lower 48; second, the upturn in our international business; third, the improving outlook for our technology and innovation; fourth, progress on our commitment to delever; and fifth, our progress in ESG and the energy transition.
Let me start with Lower 48 drilling margins.
Daily margin once again exceeded $7,000 mark.
Another way to look at our performance is to combine our drilling margin with the margins generated by NDS in the Lower 48.
That increment amounts to approximately $1,900 per day, so we're generating almost $9,000 per rig per day on this basis.
These markets collectively account for approximately 25% of our international rig count.
We currently have 38 rigs working in the Kingdom.
They are estimated to contribute approximately annualized EBITDA exceeding $50 million.
As you know, there is a long-term plan by Saudi Aramco to add successive generations of five rigs per year for an additional 45 rigs.
The Saudi Aramco procedure of this plan, we expect a similar EBITDA contribution in each successive year.
NDS' penetration on our own Lower 48 rigs with at least five services exceeded 70%.
Revenue on third-party rigs increased sequentially by more than 50%.
This sale will result in cash proceeds of approximately $94 million, plus we will liquidate the working capital in the business.
The quarter began with WTI just below $60 for early June WTI broke above 70.
This range should be conducive to increases in drilling activity across markets.
Comparing the averages of the second quarter to the first quarter, the baker Lower 48 land rig count increased by 16%.
According to Inverness, from the beginning of the second quarter through the end the Lower 48 rig count increased by 31 or approximately 6%.
The growth rate among smaller clients significantly outpaced the growth in larger operators at 8% versus 2%.
With our focus across the spectrum of clients, our average working rig count in the second quarter increased by 21%.
Once again, we surveyed the largest Lower 48 clients.
This group accounts for approximately 35% of the working rig count.
In comparison on the last call, the same group accounted for 40% of the working rig count.
The net loss from continuing operations of $196 million in the second quarter represented a loss of $26.59 per share.
Results from the quarter included a net loss of $81 million or $10.80 per share related to onetime impairments, which were largely attributable to the sale of our Canada drilling assets and to reserves for tax contingencies in our international segment.
Second-quarter results compared to a loss of $141 million or $20.16 per share in the first quarter.
Excluding the previously mentioned onetime items, the $26 million quarterly improvement primarily reflects better operational results, as well as lower depreciation and income tax expenses.
Revenue from operations for the second quarter was $489 million, a 6% improvement compared to the first quarter.
Total adjusted EBITDA expanded by almost $10 million to $117 million for the quarter.
This quarterly improvement is part of a trend that we expect to continue during the second half of the year.
drilling adjusted EBITDA of $59.8 million was up by 1 million or 1.7% sequentially and a 14% increase in revenue.
Although our rig count increased, our average margins fell in the Lower 48 market.
Lower 48 performance was in line with our expectations.
Daily rig margins came in at $7,017 and falling within our expected range.
Second-quarter Lower 48 rig count averaged 63.5 and a quarterly increase of 13%, which was somewhat above our expectations.
Currently, our rig count stands at 67.
International-adjusted EBITDA gained almost $9 million in the second quarter or 14% sequentially.
The unfavorable impact to our margins from these moves was $3.7 million in the second quarter and is forecast at $6 million in the third quarter.
Also, we lost $1.9 million of revenue in the second quarter related to the general strikes and unrest in Latin America.
Average rig count increased in line with expectation by 3.5 rigs to 68.3 or 5%.
Current rig count in the international segment is 68.
Daily gross margin for international increased by over $500 to 13,420 in the second quarter beating our expectations by more than $900.
The second quarter included approximately $900 per day in lost margin from the moves in Mexico and in rest in Latin America.
Our third quarter forecast includes approximately $1,000 in early termination fees from one of our rigs, offset by additional lost margin from the moves in Mexico.
As anticipated, Canada-adjusted EBITDA of $3 million fell by 6.7 million, reflecting the seasonal spring breakup.
Drilling solutions adjusted EBITDA of $12.8 million was up 1.3 million in the second quarter and a 10% revenue increase, trending positively in all product lines.
Penetration of the performance drilling software in the Lower 48 and TRS internationally, strengthened driving the improvement.
Lower 48 gross margin for our drilling solutions segment totaled $8.9 million for the second quarter.
This comes on top of our Lower 48 drilling gross margin of $40.5 million.
Rig technologies generated adjusted EBITDA of $2 million in the second quarter, an improvement of $2.6 million on a 34% revenue increase.
In the second quarter, total free cash flow was $68 million.
This compares to free cash flow of approximately 60 million in the first quarter.
Capital expenses in the second quarter of $77 million were up from $40 million in the first quarter.
These amounts include investments for the newbuilds of 32 million and 8 million for the second and first quarter, respectively.
In the third quarter, we forecast $80 million in capital expenditures including 35 million Versata newbuilds.
Our targeted capital spending for 2021 continues to be around $200 million, excluding approximately 100 million required for Saudi new builds.
Free cash flow for the third quarter should total around 10 to $20 million, excluding proceeds from the Canada divestiture and moderate strategic transaction outflows.
At the end of the second quarter, our cash balance closed at $400 million, and the amount drawn on our 1 billion credit facility was $558 million.
Our net debt on June 30th was $2.4 billion, down from 2.9 billion at the start of the pandemic.
Putting things in perspective, the last 15 months have probably been some of the toughest Nabors has faced.
Together with our superior operational results, we generated meaningful cash flow for the past 15 months, while also reducing our net debt by $500 million during the period.
Despite the headwinds at the beginning of last year, just before the pandemic, we also issued $1 billion of new long-term debt to address near-term maturities.

Summary:
The Saudi Aramco procedure of this plan, we expect a similar EBITDA contribution in each successive year.
This range should be conducive to increases in drilling activity across markets.
The net loss from continuing operations of $196 million in the second quarter represented a loss of $26.59 per share.
Revenue from operations for the second quarter was $489 million, a 6% improvement compared to the first quarter.
This quarterly improvement is part of a trend that we expect to continue during the second half of the year.