For the fourth quarter of 2020, revenues decreased to $148.6 million compared to $236 million in the fourth quarter of the prior year.
Adjusted loss for the fourth quarter was $11.3 million compared to an adjusted operating loss of $17.3 million in the fourth quarter of the prior year.
Adjusted EBITDA for the fourth quarter was $7.8 million compared to adjusted EBITDA of $23.2 million in the same period of the prior year.
For the fourth quarter of 2020, RPC reported a $0.03 adjusted loss per share compared to a $0.07 adjusted loss per share in the fourth quarter of the prior year.
Cost of revenues during the fourth quarter of 2020 was $117.9 million or 79.3% of revenues compared to $176.9 million or 75% of revenues during the fourth quarter of 2019.
Selling, general and administrative expenses decreased to $26 million in the fourth quarter of 2020 compared to $36.8 million in the fourth quarter of the prior year.
Depreciation and amortization decreased to $18 million in the fourth quarter of 2020 compared to $40.3 million in the fourth quarter of the prior year.
Technical Services segment revenues for the quarter decreased 36.5% compared to the same quarter in the prior year.
Segment operating loss in the fourth quarter of this year was $11.3 million compared to $17.2 million operating loss in the fourth quarter of the prior year.
Our Support Services segment revenues for the quarter decreased 43.6% compared to the same quarter in the prior year.
Segment operating loss in the fourth quarter of 2020 was $2.6 million compared to an operating profit of $1.2 million in the fourth quarter of the prior year.
And on a sequential basis, RPC's fourth quarter revenues increased 27.5%, again to $148.6 million from $116.6 million in the prior quarter, and this was due to activity increases in most of the segment service lines as a result of higher completion activity.
Cost of revenues during the fourth quarter of 2020 increased by $17 million or 16.9% to $117.9 million due to expenses, which increased with higher activity levels such as materials and supplies and maintenance expenses.
As a percentage of revenues, cost of revenues decreased from 86.5% in the third quarter of 2020 to 79.3% in the fourth quarter due to the leverage of higher revenues over certain costs including more efficient labor utilization.
Selling, general and administrative expenses during the fourth quarter of 2020 decreased 19.6% to $26 million from $32.4 million in the prior quarter.
RPC recorded impairment and other charges of $10.3 million during the quarter.
These charges included a non-cash pension settlement loss of $4.6 million and the cost to finalize the disposal of our former sand facility.
RPC incurred an operating loss of $11.3 million during the fourth quarter of 2020 compared to an adjusted operating loss of $31.8 million in the prior quarter.
RPC's adjusted EBITDA was $7.8 million in the current quarter compared to adjusted EBITDA of negative $12.3 million in the prior quarter.
Technical Services segment revenues increased by $29.7 million or 27.2% to $139 million in the fourth quarter due to increased activity levels in several service lines.
RPC's Technical Service segment incurred an $11.3 million operating loss in the current quarter compared to an operating loss of $24.9 million in the prior quarter.
Support Services segment revenues increased by $2.3 million or 32.1% to $9.7 million in the fourth quarter.
Operating loss narrowed slightly from $3.8 million in the prior quarter to $2.6 million in the current quarter.
At the end of the fourth quarter, RPC's pressure pumping capacity remained at approximately 728,000 hydraulic horsepower.
Fourth quarter 2020 capital expenditures were $12.8 million.
We currently estimate 2021 capital expenditures to be approximately $55 million.
However, while we expect activity levels to continue to improve as the year progresses, we remain committed to capital discipline.
At the end of the fourth quarter, RPC's cash balance was $84.5 million and we remain debt free.

Summary:
For the fourth quarter of 2020, revenues decreased to $148.6 million compared to $236 million in the fourth quarter of the prior year.
For the fourth quarter of 2020, RPC reported a $0.03 adjusted loss per share compared to a $0.07 adjusted loss per share in the fourth quarter of the prior year.
However, while we expect activity levels to continue to improve as the year progresses, we remain committed to capital discipline.