(5)Average cost per operating day represents operating costs incurred during the period divided by rig operating days in the period. The following costs are excluded in calculating average cost per operating day: (i) out-of-pocket costs paid by customers of $4.2 million and $3.0 million during the three months ended September 30, 2024 and 2023, respectively, and $14.4 million and $10.0 million during the nine months ended September 30, 2024 and 2023, respectively; (ii) overhead costs of $1.0 million and $0.4 million during the three months ended September 30, 2024 and 2023, respectively, and $2.3 million and $1.8 million during the nine months ended September 30, 2024 and 2023, respectively; and (iii) rig decommissioning costs of zero and $0.8 million during the three months ended September 30, 2024 and 2023, respectively, and zero and $4.3 million during the nine months ended September 30, 2024 and 2023, respectively.
Three Months Ended September 30, 2024 Compared to the Three Months Ended September 30, 2023
Revenues
Revenues for the three months ended September 30, 2024 were $38.0 million, representing a 14.0% decrease as compared to revenues of $44.2 million for the three months ended September 30, 2023. This decrease was primarily attributable to decreases in contractual dayrates and a decrease in operating days. Revenue per day decreased by 15.0% to $27,994 during the three months ended September 30, 2024, as compared to revenue per day of $32,925 during the three months ended September 30, 2023. Operating days decreased to 1,207 days during the three months ended September 30, 2024 as compared to 1,229 days during the three months ended September 30, 2023.
Operating Costs
Operating costs for the three months ended September 30, 2024 were $29.7 million, representing a 7.9% increase as compared to operating costs of $27.5 million for the three months ended September 30, 2023. This increase was primarily attributable to a decrease in operating days, offset by an increase in cost per day in the current quarter. Operating days decreased to 1,207 days during the three months ended September 30, 2024, which included 7.0 standby days, as compared to 1,229 days during the three months ended September 30, 2023, which included 92.3 standby days. Rigs on standby typically incur lower operating costs than operating rigs. Operating costs per day increased to $20,268 during the three months ended September 30, 2024, representing a 7.1% increase compared to cost per operating day of $18,920 for the three months ended September 30, 2023. Additionally, the higher cost per operating day during the third quarter of 2024 compared to historical and normalized levels was driven by higher than normal rig churn, which we expect to return to normalized levels in 2025 as we recontract rigs released following the merger between two of our customers, including our largest customer.
Selling, General and Administrative
Selling, general and administrative expenses for the three months ended September 30, 2024 were $3.6 million, representing a 48.0% decrease as compared to selling, general and administrative expense of $6.9 million for the three months ended September 30, 2023. This decrease in selling, general and administrative expenses as compared to the prior year comparable period primarily relates to decreased stock-based and deferred compensation expense of $1.8 million primarily associated with the variable accounting of phantom awards and lower expenses as a result of cost cutting initiatives implemented during the first quarter of 2024 of approximately $0.8 million, offset by $0.4 million of costs associated with the special committee to assess refinancing and other strategic opportunities in regards to our Convertible Notes. Additionally, during the three months ended September 30, 2023, we incurred $1.1 million of credit loss expense.
Depreciation and Amortization
Depreciation and amortization expense for the three months ended September 30, 2024 was $13.0 million, representing a 27.0% increase compared to depreciation and amortization expense of $10.2 million for the three months ended September 30, 2023.
Asset impairment, net
During the three months ended September 30, 2023, we impaired a damaged piece of drilling equipment for $0.3 million, net of insurance recoveries.