(Stated in millions)

	Mar. 31,		Dec. 31,
	2021		2020
3.65% Senior Notes due 2023	$	1,496	$	1,496
3.90% Senior Notes due 2028		1,452		1,450
2.65% Senior Notes due 2030		1,250		1,250
1.375% Guaranteed Notes due 2026		1,173		1,221
2.00% Guaranteed Notes due 2032		1,167		1,214
0.25% Notes due 2027		1,057		1,100
0.50% Notes due 2031		1,056		1,099
2.40% Senior Notes due 2022		999		999
4.00% Senior Notes due 2025		930		930
4.30% Senior Notes due 2029		845		846
3.75% Senior Notes due 2024		747		746
1.00% Guaranteed Notes due 2026		703		736
0.00% Notes due 2024		588		611
2.65% Senior Notes due 2022		599		598
1.40% Senior Notes due 2025		498		498
3.63% Senior Notes due 2022		295		295
7.00% Notes due 2038		205		206
5.95% Notes due 2041		113		114
5.13% Notes due 2043		99		99
4.00% Notes due 2023		80		80
3.70% Notes due 2024		55		55
Commercial paper borrowings		427		393
	$	15,834	$	16,036

The estimated fair value of Schlumberger’s Long-term Debt, based on quoted market prices at March 31, 2021 and December 31, 2020, was $17.5 billion and $17.3 billion, respectively.

During the second quarter of 2020, Schlumberger entered into a €1.54 billion one-year committed revolving credit facility. In March 2021, Schlumberger exercised an option to extend this facility for six months. This facility can be extended for a further six months at Schlumberger’s election. In April 2021, Schlumberger reduced the size of the facility to €0.75 billion. At March 31, 2021 no amounts had been drawn under this facility.

In addition to the revolving credit facility described above, at March 31, 2021, Schlumberger had separate committed credit facility agreements aggregating $6.25 billion with commercial banks, of which $5.82 billion was available and unused. These committed facilities support commercial paper programs in the United States and Europe, of which $2.75 billion matures in February 2023, $2.0 billion matures in February 2025 and $1.5 billion matures in July 2025. Interest rates and other terms of borrowing under these lines of credit vary by facility.

Borrowings under the commercial paper programs at both March 31, 2021 and December 31, 2020 were $0.4 billion, all of which was classified in Long-term debt in the Consolidated Balance Sheet.

During the first quarter of 2020, Schlumberger issued €400 million of 0.25% Notes due 2027 and €400 million of 0.50% Notes due 2031.

Schlumberger Limited fully and unconditionally guarantees the securities issued by certain of its subsidiaries, including securities issued by Schlumberger Investment SA and Schlumberger Finance Canada Ltd., both wholly-owned subsidiaries of Schlumberger.