On a U.S. GAAP basis for the second quarter of 2021, NOV reported revenues of $1.42 billion and a net loss of $26 million.
During the second quarter of 2021, NOV's consolidated revenue increased 8% sequentially, and EBITDA improved to $47 million, excluding the benefit arising from the cancellation of certain offshore rig projects.
Operating leverage was strong at 50%, owing to cost reductions in prior periods, while price increases in certain product lines helped offset the inflation we are seeing in most product lines.
Rig Technologies posted book-to-bill of 138% and on strength in orders for renewables.
And Completion & Production Solutions book-to-bill ran 167% in the second quarter.
Its last two quarters have seen it put up double-digit top line growth at greater than 50% EBITDA leverage, benefiting from the outstanding execution of cost reductions through the downturn as well as selected price increases where possible.
Book-to-bill's above 100% for both in the second quarter also support our outlook.
Overall, excluding the rig cancellation, NOV's consolidated North American revenues increased 22% in the second quarter, and international revenues increased 1%.
Consolidated offshore revenues declined 5% sequentially in the quarter.
Every business unit, with the exception of our Intervention & Stimulation Equipment business, posted book-to-bill ratios above 100%.
The 11% sequential improvement in spare parts bookings during the quarter, more inquiries around rig reactivations and more engineering work we are being asked to do around upgrading BOPs, automating pipe handling and adding Crown Mounted compensators gives us confidence that we are seeing more offshore drilling activity on the horizon.
The wind propulsion technology will supplement conventional propulsion systems and is expected to reduce the ship's carbon footprint by 40% to 50%.
And Tuboscope's TK liner product line is becoming an indispensable piece of large geothermal projects internationally as evidenced by a contract award this quarter for approximately 60,000 feet of large diameter product.
Our NOVOS operating system is at work today on 74 drilling rigs with another 84 in backlog, enabling these land and offshore rigs to access 10 different optimization applications written by NOV and third parties.
Several customers came out to see our cost-effective industrial robots Dope and Trip over 25 stands per hour without any human hands touching the pipe or the controls.
For the second quarter of 2021, NOV's consolidated revenue rose 13% sequentially to $1.42 billion, and EBITDA was $104 million or 7.3% of sales.
Second quarter revenue included $74 million related to the final cash settlement and cost reimbursement from the cancellation of offshore project -- offshore rig projects.
Excluding the settlement, revenue rose 8% sequentially to $1.34 billion and EBITDA was $47 million or 3.5% of sales.
Consolidated U.S. revenue increased 27% sequentially, significantly outpacing the growth in U.S. drilling activity.
International revenues, excluding the settlement, improved only 1% but we began to see international growth accelerate late in the second quarter.
50% incremental margins were the result of better absorption across our manufacturing base, better management of supply chain disruptions price improvements in certain areas and cost savings initiatives, which have nearly achieved our target for the year.
Efforts to improve capital efficiencies across the organization helped drive $177 million in cash flow from operations.
Capital expenditures totaled $49 million, resulting in $128 million of free cash flow.
During the second quarter, we redeemed the remaining $183 million of our senior notes due in December 2022, and we ended the quarter with $1.6 billion of cash, $1.7 billion of gross debt and only $114 million of net debt.
Our Wellbore Technologies segment generated $463 million in revenue during the second quarter, an increase of $50 million or 12% sequentially.
Revenue improved 14% in North America and 10% in international markets as the early stages of a global recovery began to expand beyond the Western Hemisphere.
An improved cost structure, higher volumes and pricing improvements more than offset inflationary costs and drove 58% incremental margins, resulting in a $29 million increase in revenue to $63 million or 13.6% of sales.
Our ReedHycalog drill bit business posted solid top line growth, led by a 25% sequential improvement in U.S. revenue, resulting from improving activity and market share gains.
Outside North America, sales improved 10% sequentially with our NOC customers, signaling an intent to continue increasing activity over the next several quarters.
Our downhole tools business reported a 13% sequential improvement in revenue, with most major regions realizing double-digit percentage growth.
Demand for capital equipment began to show signs of life in the second quarter, with bookings improving 1.7 times off the very low mark realized in the first quarter of 2021.
Revenue from surface sensor and data acquisition sales and rentals improved 20% due to higher drilling activity and market share gains.
Our Tuboscope pipe coating and inspection business posted an 11% sequential increase in revenue with strong incremental margins during the quarter, driven by a sharp increase in demand for our tubular coating services across all major market.
We received an order for 121,000 feet of 12-inch line pipe for a saltwater disposal system in the Haynesville as well as an order for 14,000 feet of 16-inch line pipe for a system in the Permian.
Our Grant Prideco drill pipe business posted revenue growth of 11% on higher sales of drill pipe and the delivery of the industry's first three million-pound 20,000 psi-rated landing string.
For our Wellbore Technologies segment, we expect accelerating activity in the Eastern Hemisphere and modest improvements in the Western Hemisphere to result in 6% to 10% sequential growth in the third quarter.
We anticipate improved absorption rates and higher pricing will be partially offset by inflationary pressures, ongoing raw material shortages and a less favorable product mix in our drill pipe business, limiting incremental margins to the mid-20% range during the third quarter.
Our Completion & Production Solutions segment generated $497 million in revenue during the second quarter, an increase of $58 million or 13% sequentially.
Lower margin sales, inflationary pressures and operational disruptions limited incremental margins to 14%, resulting in EBITDA of $4 million or 0.8% of sales.
Orders improved 37% sequentially, totaling $462 million for a book-to-bill of 167%.
All but one business unit achieved a book-to-bill of above 100% and the step change in order intake resulted in the segment achieving its highest booking quarter since 2019.
Backlog for the segment at the end of the quarter was just north of $1 billion.
Field trials for our e-frac system have validated its ability to significantly reduce maintenance costs and increase pump volume nearly 4 times compared to conventional equipment while significantly reducing emissions.
Orders increased 2.6 times over the first quarter, and our pipeline of opportunities remains strong.
Delays in final customer acceptance slowed production during the quarter, but order intake grew 85% sequentially, both of which should allow the unit to post better results in the third quarter.
Our Fiberglass business unit reported a 13% sequential increase in revenue with solid EBITDA flow-through despite a continuation of global supply chain and COVID-related difficulties.
We've seen certain raw material prices increase upwards of 40% and shipping costs increased fourfold compared to 24 months ago.
Despite the difficult operating environment, our fiberglass business achieved its highest level of backlog in the last five quarters and we're finally beginning to see a pickup in demand for midstream customers in the U.S. For the third quarter of 2021, we anticipate revenue from our Completion & Production Solutions segment will improve between 5% to 10% sequentially, with incremental margins in the low 30% range.
Our Rig Technologies segment generated revenues of $487 million in the second quarter, an increase of $56 million or 13% sequentially.
Second quarter revenues included $74 million related to the final settlement from the cancellation of certain offshore rig projects.
Excluding the impact of the settlement, revenues declined $18 million sequentially to $413 million as improving aftermarket sales and progress on land rig projects were more than offset by lower offshore rig equipment sales.
Adjusted EBITDA, excluding $57 million from the settlement, improved $5 million to $18 million or 4.4% of sales due to a higher margin mix and improved operational efficiencies.
Capital equipment orders for the segment more than doubled to $232 million, yielding a book-to-bill of 138%.
As Clay mentioned, more than 50% of our Q2 orders related to wind installation vessel equipment where NOV's engineering designs and equipment continue to be the market standards.
Orders received in Q2 position us well to achieve our stated target of a $200 million annual revenue run rate in our wind business by year-end.
While awards have been robust during the past 12 months, we expect this momentum to continue and see the potential for our wind-related revenues to achieve a run rate of between $350 million and $400 million by the end of 2022.
During the second quarter, our aftermarket sales improved 3% sequentially with spare part bookings growing 11%.
For the third quarter, we expect revenues for our Rig Technologies segment to remain in line with the second quarter, excluding the impact of the settlement with margins that are flat to down 200 basis points.

Summary:
On a U.S. GAAP basis for the second quarter of 2021, NOV reported revenues of $1.42 billion and a net loss of $26 million.
For the second quarter of 2021, NOV's consolidated revenue rose 13% sequentially to $1.42 billion, and EBITDA was $104 million or 7.3% of sales.