We have various equity incentive compensation plans which provide for the granting of restricted common stock, options for the purchase of our common stock, and other performance-based, equity-based compensation awards to our executive officers, key employees, nonexecutive officers, consultants, and directors. Incentive stock options are exercisable for periods of up to ten years. Compensation cost for all share-based payments is based on the grant date fair value and is recognized in earnings over the requisite service period. Total equity-based compensation expense for the three years ended December 31, 2011, 2010, and 2009 was $6.3 million, $7.2 million, and $6.7 million, respectively, which approximated the fair value of equity-based compensation awards vesting during the periods.

The Black-Scholes option-pricing model is used to estimate option fair values. This option-pricing model requires a number of assumptions, of which the most significant are: expected stock price volatility, the expected pre-vesting forfeiture rate, and the expected option term (the amount of time from the grant date until the options are exercised or expire). Expected volatility was calculated based upon actual historical stock price movements over the most recent periods ending December 31, 2011, equal to the expected option term. Expected pre-vesting forfeitures were estimated based on actual historical pre-vesting forfeitures over the most recent periods ending December 31, 2011, for the expected option term.

The TETRA Technologies, Inc. 1990 Stock Option Plan (the 1990 Plan) was initially adopted in 1985 and subsequently amended to change the name, the number, and the type of options that could be granted, as well as the time period for granting stock options. As of December 31, 2004, no further options may be granted under the 1990 Plan. We granted performance stock options under the 1990 Plan to certain executive officers. These granted options have an exercise price per share of not less than the market value at the date of issuance and are fully vested and exercisable.

In 1993, we adopted the TETRA Technologies, Inc. Director Stock Option Plan (the Directors' Plan). In 1996, the Directors' Plan was amended to increase the number of shares issuable under automatic grants thereunder. In 1998, we adopted the TETRA Technologies, Inc. 1998 Director Stock Option Plan as amended (the 1998 Director Plan). The purpose of the Directors' Plan and the 1998 Director Plan (together the Director Stock Option Plans) is to enable us to attract and retain qualified individuals to serve as our directors and to align their interests more closely with our interests. The 1998 Director Plan is funded with our treasury stock and was amended and restated effective December 18, 2002, to increase the number of shares issuable thereunder, to change the types of options that may be granted thereunder, and to increase the number of shares issuable under automatic grants thereunder. The 1998 Director Plan was amended and restated effective June 27, 2003, and was further amended in December 2005 to increase the number of shares issuable thereunder. As of May 2, 2006, no further options may be granted under the Director Stock Option Plans.

During 1996, we adopted the 1996 Stock Option Plan for Nonexecutive Employees and Consultants (the Nonqualified Plan) to enable us to award nonqualified stock options to nonexecutive employees and consultants who are key to our performance. As of May 2, 2006, no further options may be granted under the Nonqualified Plan.

In May 2006, our stockholders approved the adoption of the TETRA Technologies, Inc. 2006 Equity Incentive Compensation Plan. Pursuant to the TETRA Technologies, Inc. 2006 Equity Incentive Compensation Plan, we were authorized to grant up to 1,300,000 shares in the form of stock options (including incentive stock options and nonqualified stock options); restricted stock; bonus stock; stock appreciation rights; and performance awards to employees, consultants, and non-employee directors. As a result of the May 2006 adoption and approval of the TETRA Technologies, Inc. 2006 Equity Incentive Compensation Plan, no further awards may be granted under our other previously existing plans. As of May 4, 2008, no further awards may be granted under the TETRA Technologies, Inc. 2006 Equity Incentive Compensation Plan.

In May 2007, our stockholders approved the adoption of the TETRA Technologies, Inc. 2007 Equity Incentive Compensation Plan. In May 2008, our stockholders approved the adoption of the TETRA Technologies, Inc. Amended and Restated 2007 Equity Incentive Compensation Plan, which among other changes, resulted in an increase in the maximum number of shares authorized for issuance. In May 2010, our stockholders approved further amendments to the TETRA Technologies, Inc. Amended and Restated 2007 Equity Incentive Compensation Plan (renamed as the 2007 Long Term Incentive Compensation Plan) which, among other changes, resulted in an additional increase in the maximum number of shares authorized for issuance. Pursuant to the 2007 Long Term Incentive Compensation Plan, we are authorized to grant up to 5,590,000 shares in the form of stock options (including incentive stock options and nonqualified stock options); restricted stock; bonus stock; stock appreciation rights; and performance awards to employees, consultants, and non-employee directors.

In May 2011, our stockholders approved the adoption of the TETRA Technologies, Inc. 2011 Long Term Incentive Compensation Plan. Pursuant to this plan, we were authorized to grant up to 2,200,000 shares in the form of stock options, restricted stock, bonus stock, stock appreciation rights, and performance awards to employees, consultants, and non-employee directors.

In June 2011, the Compressco Partners, L.P. 2011 Long Term Incentive Plan (Compressco Partners Long Term Incentive Plan) was adopted by the board of directors of Compressco Partners' general partner. The plan is intended to promote Compressco Partners' interests by providing to employees, consultants, and directors of its general partner incentive compensation based on common units, to encourage superior performance. The Compressco Partners Long Term Incentive Plan provides for grants of restricted units, phantom units, unit awards and other unit-based awards up to a plan maximum of 1,537,122 common units. The plan is also intended to attract and retain the services of individuals who are essential for the growth and profitability of Compressco Partners and its affiliates.

During each of the three years ended December 31, 2011, we granted to certain officers and employees restricted shares, which generally vest over a three to five year period. During 2011, we granted a total of 397,907 restricted shares, having an average market value (equal to the closing price of the common stock on the dates of grant) of $12.43 per share, or an aggregate market value of $4.9 million. During 2010, we granted a total of 434,101 restricted shares, having an average market value (equal to the closing price of the common stock on the dates of grant) of $10.20 per share, or an aggregate market value of $4.4 million. During 2009, we granted a total of 98,053 restricted shares, having an average market value (equal to the quoted closing price of the common stock on the dates of grant) of $8.07 per share, or an aggregate market value of $0.8 million, at the date of grant. The fair value of awards vesting during 2011, 2010, and 2009, was approximately $5.2 million, $2.4 million, and $2.7 million, respectively.

				Weighted Average
				Grant Date Fair
	Shares			Value Per Share
	(In Thousands)

Nonvested restricted shares outstanding at December 31, 2010		542		$	13.92
Shares granted		398			12.43
Shares cancelled		(71	)		13.43
Shares vested		(357	)		14.56
Nonvested restricted shares outstanding at December 31, 2011		512		$	12.38

During 2011, and subsequent to the adoption of the Compressco Partners Long Term Incentive Plan, Compressco Partners granted restricted common units that generally vest over a three year period to certain employees, officers and directors of its general partner. Each of the restricted unit awards includes unit distribution rights that enable the recipient to receive accumulated cash distributions on the restricted units in the same amounts as unitholders receive cash distributions on common units. Accumulated distributions associated with each underlying restricted unit are payable upon vesting of the related restricted unit (and are forfeited if the related restricted unit is forfeited). While the initial grants of restricted units vest solely with respect to the passage of time, the Compressco Partners Long Term Incentive Plan also provides for awards of restricted units with performance-based vesting conditions. Awards that vest subject to performance-based vesting conditions are intended to further align the interests of key employees, directors and consultants of Compressco Partners' general partner with those of its unitholders.

				Weighted Average
	Shares			Option Price
	Under Option			Per Share
	(In Thousands)

Outstanding at December 31, 2010		5,875		$	11.50
Options granted		478			12.89
Options cancelled		(583	)		14.58
Options exercised		(1,452	)		6.77
Outstanding at December 31, 2011		4,318		$	12.83

Expected to vest		1,043		$	13.53
Exercisable, end of year		3,275			12.60
Available for grant, end of year		2,758

The total intrinsic value, or the difference between the exercise price and the market price on the date of exercise, of all options exercised during the three years ended December 31, 2011, 2010, and 2009, was approximately $2.5 million, $1.8 million, and $0.8 million, respectively. The intrinsic value of options outstanding as of December 31, 2011 was $7.9 million, the intrinsic value of options expected to vest as of December 31, 2011 was $0.9 million, and the intrinsic value of options exercisable as of December 31, 2011 was $7.0 million. Cash received from stock options exercised during the three years ended December 31, 2011, 2010, and 2009, was $3.4 million, $1.3 million, and $1.2 million, respectively. Recognized excess tax benefits related to the exercise of stock options during the three years ended December 31, 2011, 2010, and 2009, were $1.3 million, $0.5 million, and $0.2 million, respectively.

	Year Ended December 31,
	2011	2010	2009

Expected stock price volatility	72% to 75%	72% to 73%	65% to 73%
Expected life of options	4.7 years	4.7 years	4.7 years
Risk free interest rate	0.87% to 2.24%	1.3% to 2.8%	1.9% to 2.6%
Expected dividend yield	-	-	-

The weighted average fair value of options granted during the years ended December 31, 2011, 2010 and 2009 using the Black-Scholes model was $7.55, $6.00, and $2.73 per share, respectively. Total estimated unrecognized compensation cost from unvested stock options and restricted stock as of December 31, 2011, was approximately $10.6 million, which is expected to be recognized over a weighted average period of approximately 1.1 years.

During 2011, 2010, and 2009, we received 52,065, 6,048 and 6,318 shares, respectively, of our common stock related to the vesting of certain employee restricted stock. Such surrendered shares received by us are included in treasury stock. At December 31, 2011, net of options previously exercised pursuant to our various stock option plans, we have a maximum of 7,588,617 shares of common stock issuable pursuant to stock options previously granted and outstanding and stock options authorized to be granted in the future.