Our 2.125% Convertible Senior Notes (2.125% Notes) are scheduled to mature in July 2012. As a result, the $125.0 million aggregate principal amount of the 2.125% Notes is classified as a current obligation on our consolidated balance sheet at March 31, 2012. Subsequent to quarter end, we issued an additional $125.0 million aggregate principal amount of our existing 9.125% Senior Notes (9.125% Notes) at a price of 104.0% of par, resulting in gross proceeds of $130.0 million. Net proceeds from the offering will be utilized to repurchase the 2.125% Notes pursuant to a tender offer commenced on April 11, 2012 or to repay any non-tendered 2.125% Notes at their stated maturity, July 15, 2012. The tender offer price is $1,003.27 for each $1,000 principal amount of 2.125% Notes, plus accrued and unpaid interest.

The following table illustrates the Company’s current debt portfolio as of March 31, 2012 and December 31, 2011:

9.125% Senior Notes, due April 2018

On March 22, 2010, we issued $300.0 million aggregate principal amount of 9.125% Senior Notes due 2018 (9.125% Notes) pursuant to an Indenture between the Company and The Bank of New York Mellon Trust Company, N.A. (Trustee). The 9.125% Notes were issued at par with interest payable on April 1 and October 1 of each year, beginning October 1, 2010. Net proceeds from the 9.125% Notes offering were primarily used to redeem the $225.0 million aggregate principal amount of our 9.625% Senior Notes due 2013 and to repay $42.0 million of borrowings under our Revolver. As noted above, we issued and sold an additional $125.0 million aggregate principal amount of 9.125% Notes in April 2012.

The 9.125% Notes are general unsecured obligations of the Company and rank equal in right of payment with all of our existing and future senior unsecured indebtedness. The 9.125% Notes are jointly and severally guaranteed by substantially all of our direct and indirect domestic subsidiaries other than immaterial subsidiaries and subsidiaries generating revenue primarily outside the United States.

At any time prior to April 1, 2013, we may redeem up to 35 percent of the aggregate principal amount of the 9.125% Notes at a redemption price of 109.125 percent of the principal amount, plus accrued and unpaid interest to the redemption date, with the net cash proceeds of certain equity offerings by us. On and after April 1, 2014, we may redeem all or a part of the 9.125% Notes upon appropriate notice, at a redemption price of 104.563 percent of the principal amount, and at redemption prices decreasing each year thereafter to par. If we experience certain changes in control, we must offer to repurchase the 9.125% Notes at 101.0 percent of the aggregate principal amount, plus accrued and unpaid interest and additional interest, if any, to the date of repurchase.

The Indenture restricts our ability and the ability of certain subsidiaries to: (i) sell assets; (ii) pay dividends or make other distributions on capital stock or redeem or repurchase capital stock or subordinated indebtedness; (iii) make investments; (iv) incur or guarantee additional indebtedness; (v) create or incur liens; (vi) enter into sale and leaseback transactions; (vii) incur dividend or other payment restrictions affecting subsidiaries; (viii) merge or consolidate with other entities; (ix) enter into transactions with affiliates; and (x) engage in certain business activities. Additionally, the Indenture contains certain restrictive covenants designating certain events as Events of Default. These covenants are subject to a number of important exceptions and qualifications.

2.125% Convertible Senior Notes, due July 2012

On July 5, 2007, we issued $125.0 million aggregate principal amount of 2.125% Convertible Senior Notes (2.125% Notes) due July 2012. As of March 31, 2012, the 2.125% Notes are classified as current debt in our consolidated condensed balance sheet.

The significant terms of the 2.125% Notes are as follows:

As of March 31, 2012 and December 31, 2011, none of the conditions allowing holders of the 2.125% Notes to convert had been met. However, as of April 15, 2012, holders may surrender convertible notes for conversion at any time until the close of business on the second business day immediately preceding the maturity date.

Concurrently with the issuance of the 2.125% Notes, we purchased a convertible note hedge (note hedge) and sold warrants in private transactions with counterparties that were different than the ultimate holders of the 2.125% Notes. The note hedge included purchasing free-standing call options and selling free-standing warrants, both exercisable in our common shares. The note hedge allows us to receive shares of our common stock from the counterparties to the transaction equal to the amount of common stock related to the excess conversion value that we would issue and/or pay to the holders of the 2.125% Notes upon conversion.

The terms of the call options mirror the 2.125% Notes’ major terms whereby the call option strike price is the same as the initial conversion price as are the number of shares callable, $13.85 per share and 9,027,713 shares, respectively. This feature prevents dilution of our outstanding shares. The warrants allow us to sell 9,027,713 common shares at a strike price of $18.29 per share. The conversion price of the 2.125% Notes remains at $13.85 per share, and the existence of the call options and warrants serve to guard against dilution at share prices less than $18.29 per share, since we would be able to satisfy our obligations and deliver shares upon conversion of the 2.125% Notes with shares that are obtained by exercising the call options.

We paid a premium of approximately $31.5 million for the call options, and received proceeds for a premium of approximately $20.3 million for the sale of the warrants. This reduced the net cost of the note hedge to $11.2 million. The expiration date of the note hedge is the earlier of the last day on which the 2.125% Notes remain outstanding or the maturity date of the 2.125% Notes.

The 2.125% Notes are classified as a liability in our consolidated condensed balance sheets. Because we have the choice of settling the call options and the warrants in cash or shares of our common stock and these contracts meet all of the applicable criteria for equity classification, the cost of the call options and proceeds from the sale of the warrants are classified in stockholders’ equity in the consolidated condensed balance sheets. In addition, because both of these contracts are classified in stockholders’ equity and are indexed solely to our common stock, they are not accounted for as derivatives.

Debt issuance costs related to the 2.125% Notes of approximately $3.6 million are being amortized over the five year term of the 2.125% Notes using the effective interest method. As of March 31, 2012, the unamortized debt issuance costs were $0.2 million. Holders may surrender convertible notes for conversion at any time on or after April 15, 2012 until the close of business on the second business day immediately preceding the maturity date. Proceeds from the transaction of $110.2 million were used to redeem our outstanding senior floating rate notes, to pay the net cost of hedge and warrant transactions, and for general corporate purposes. As noted above, on April 11, 2012 we commenced a tender offer to purchase any and all of the 2.125% Notes.

Credit Agreement:

On May 15, 2008, we entered into a credit agreement (Credit Agreement) consisting of a senior secured $80.0 million revolving credit facility (Revolver) and senior secured term loan facility (Term Loan) of up to $50.0 million. The Credit Agreement provides that, subject to certain conditions, including the approval of the Administrative Agent and the lenders’ acceptance (or additional lenders being joined as new lenders), the amount of the Term Loan or Revolver could be increased by an additional $50.0 million, so long as after giving effect to such increase, the Aggregate Commitments shall not be in excess of $180.0 million. On April 1, 2011, the Company exercised the additional $50.0 million accordion feature and entered into an amendment to the Credit Agreement that increased the Aggregate Commitment under the Credit Agreement to $159.0 million, and borrowed an additional $50.0 million in a Term Loan. When the facility was increased, all other terms of the Credit Agreement remained the same, including covenants and Applicable Rates (as defined in the Credit Agreement).

Our obligations under the Credit Agreement are guaranteed by substantially all of our domestic subsidiaries, each of which has executed guaranty agreements. The Credit Agreement contains customary affirmative and negative covenants with which we were in compliance as of March 31, 2012 and December 31, 2011. The Credit Agreement terminates on May 14, 2013.

Revolver:

Our Revolver is available for general corporate purposes and to support letters of credit. Interest on Revolver loans accrues at a Base Rate plus an Applicable Rate or LIBOR plus an Applicable Rate. The Applicable Rate varies from a rate per annum ranging from 2.75 percent to 3.25 percent for LIBOR rate loans and 1.75 percent to 2.25 percent for base rate loans, determined by reference to the consolidated leverage ratio (as defined in the Credit Agreement). Revolving loans are available subject to a borrowing base calculation based on a percentage of eligible accounts receivable, certain specified barge drilling rigs and rental equipment of the Company and its subsidiary guarantors. There were no revolving loans outstanding at March 31, 2012 or December 31, 2011. Letters of credit outstanding totaled $2.7 million as of March 31, 2012 and December 31, 2011.

Term Loan:

The Term Loan originated at $50.0 million and required quarterly principal payments of $3.0 million. Interest on the Term Loan accrues at either a Base Rate plus 2.25 percent or LIBOR plus 3.25 percent. On April 1, 2011, the company expanded its Term Loan Facility by $50.0 million. Funding was provided by certain current lenders and Barclays Bank PLC, which joined as a lender under the Credit Agreement. We used the proceeds from the additional Term Loan to repay the $25.0 million outstanding on the Revolver, purchase additional rental tool inventory, and for general corporate purposes. The additional Term Loan amortizes $3.0 million per quarter beginning June 30, 2011. Upon the completion of the transaction, total borrowings under the Term Loan Facility were $79.0 million. Amortization on the Term Loans is $6.0 million per quarter. The outstanding balance on the Term Loan at March 31, 2012 and December 31, 2011 was $55.0 million and $61.0 million, respectively.