9. Long-term Debt

A summary of Long-term Debt follows:

(Stated in millions)
	Mar. 31,		Dec. 31,
	2015		2014
3.30% Senior Notes due 2021	$	1,597	$	1,597
3.65% Senior Notes due 2023		1,496		1,495
1.95% Senior Notes due 2016		1,100		1,100
4.20% Senior Notes due 2021		1,100		1,100
1.25% Senior Notes due 2017		1,000		1,000
2.40% Senior Notes due 2022		999		999
1.50% Guaranteed Notes due 2019		561		628
2.65% Senior Notes due 2016		—		500
Commercial paper borrowings		444		1,538
Other		601		608
	$	8,898	$	10,565

The estimated fair value of Schlumberger’s Long-term Debt at March 31, 2015 and December 31, 2014, based on quoted market prices, was $9.2 billion and $10.7 billion, respectively.

Borrowings under the commercial paper program at March 31, 2015 were $2.0 billion, of which $1.6 billion is classified within Long-term debt – current portion in the Consolidated Balance Sheet. At December 31, 2014, borrowings under the commercial paper program were $1.5 billion, all of which were classified within Long-term debt in the Consolidated Balance Sheet.