Schlumberger has three types of stock-based compensation programs: (i) stock options, (ii) a restricted stock, restricted stock unit and performance share unit program (collectively referred to as “restricted stock”), and (iii) a discounted stock purchase plan (“DSPP”).

Key employees may be granted stock options under Schlumberger stock option plans. The exercise price equals the average of the high and low sales prices of Schlumberger stock on the date of grant. The maximum term is 10 years, and the options generally vest in increments over five years.

The fair value of each stock option grant was estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted-average assumptions and resulting weighted-average fair value per share:

	2020			2019			2018
Dividend yield		5.2	%		4.8	%		2.6	%
Expected volatility		26	%		25	%		26	%
Risk-free interest rate		1.7	%		2.7	%		2.6	%
Expected option life in years		7.0			7.0			7.0
Weighted-average fair value per share	$	5.07		$	6.21		$	17.37

The following table summarizes information related to options outstanding and options exercisable as of December 31, 2020:

	(Shares stated in thousands)

	Options Outstanding						Options Exercisable
			Weighted-
			Average
			Remaining		Weighted-				Weighted-
	Options		Contractual Life		Average		Options		Average
Exercise prices range	Outstanding		(in years)		Exercise Price		Exercisable		Exercise Price
$38.75 - $69.98		15,562		7.7	$	44.48		3,846	$	56.69
$70.31 - $76.74		9,462		2.1	$	72.10		9,399	$	72.06
$77.10 - $83.15		7,303		5.4	$	79.29		5,425	$	79.52
$83.89 - $88.77		8,549		3.0	$	85.96		7,097	$	85.66
$90.00 - $114.83		7,396		3.4	$	95.79		7,396	$	95.79
		48,272		4.8	$	70.37		33,163	$	79.70

The weighted-average remaining contractual life of stock options exercisable as of December 31, 2020 was 3.3 years.

The following table summarizes stock option activity during the years ended December 31, 2020, 2019 and 2018:

	(Shares stated in thousands)

	2020					2019					2018
				Weighted-					Weighted-					Weighted-
				Average					Average					Average
				Exercise					Exercise					Exercise
	Shares			Price		Shares			Price		Shares			Price
Outstanding at beginning of year		46,269		$	75.65		43,529		$	79.36		47,210		$	79.13
Granted		7,468		$	38.75		5,604		$	41.50		2,121		$	76.95
Exercised		-		$	-		(1,045	)	$	38.50		(936	)	$	54.20
Forfeited		(5,465	)	$	71.86		(1,819	)	$	74.69		(4,866	)	$	84.19
Outstanding at year-end		48,272		$	70.37		46,269		$	75.65		43,529		$	79.36

Stock options outstanding and stock options exercisable as of December 31, 2020 had no intrinsic value.

The total intrinsic value of options exercised during the years ended December 31, 2019 and 2018 was $4 million and $15 million, respectively. There were no stock options exercised during the year ended December 31, 2020.

Schlumberger grants performance share units to its executive officers. The number of shares earned is determined at the end of each performance period based on Schlumberger’s achievement of certain predefined targets as defined in the underlying performance share unit agreement. In the event Schlumberger exceeds the predefined target, shares for up to the maximum of 250% of the target award may be awarded. In the event Schlumberger falls below the predefined target, a reduced number of shares may be awarded. If

Schlumberger falls below the threshold award performance level, no shares will be awarded. As of December 31, 2020, 3.8 million performance share units were outstanding assuming the achievement of 100% of target.

All other restricted stock awards generally vest at the end of three years or vest ratably in equal tranches over a three-year period.

Restricted stock awards do not pay dividends or have voting rights prior to vesting. Accordingly, the fair value of a restricted stock award is the quoted market price of Schlumberger’s stock on the date of grant less the present value of the expected dividends not received prior to vesting.

The following table summarizes information related to restricted stock transactions:

	(Shares stated in thousands)

	2020					2019					2018
				Weighted-					Weighted-					Weighted-
				Average					Average					Average
	Restricted			Grant Date		Restricted			Grant Date		Restricted			Grant Date
	Stock			Fair Value		Stock			Fair Value		Stock			Fair Value
Unvested at beginning of year		11,822		$	49.86		6,951		$	70.13		5,428		$	72.33
Granted		10,637		$	26.53		7,888		$	35.56		3,204		$	70.54
Vested		(3,059	)	$	71.56		(2,722	)	$	72.09		(982	)	$	77.62
Forfeited		(637	)	$	45.95		(295	)	$	57.41		(699	)	$	70.67
Unvested at year-end		18,763		$	35.24		11,822		$	49.86		6,951		$	70.13

Under the terms of the DSPP, employees can choose to have a portion of their earnings withheld, subject to certain restrictions, to purchase Schlumberger common stock. The purchase price of the stock is 92.5% of the lower of the stock price at the beginning or end of the plan period at six-month intervals.

The fair value of the employees’ purchase rights under the DSPP was estimated using the Black-Scholes model with the following assumptions and resulting weighted-average fair value per share:

	2020			2019			2018
Dividend yield		4.0	%		5.3	%		2.9	%
Expected volatility		43	%		30	%		22	%
Risk-free interest rate		0.88	%		2.3	%		1.6	%
Weighted-average fair value per share	$	5.38		$	5.81		$	9.01

(Stated in millions)

	2020		2019		2018
Stock options	$	75	$	99	$	134
Restricted stock		293		274		179
DSPP		29		32		32
	$	397	$	405	$	345

At December 31, 2020, there was $335 million of total unrecognized compensation cost related to nonvested stock-based compensation arrangements, of which $198 million is expected to be recognized in 2021, $102 million in 2022, $26 million in 2023, and $9 million in 2024.

As of December 31, 2020, approximately 16 million shares of Schlumberger common stock were available for future grants under Schlumberger’s stock-based compensation programs.