The following table illustrates the Company’s debt portfolio as of September 30, 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 (9.125% Notes) pursuant to an Indenture between the Company and The Bank of New York Mellon Trust Company, N.A., as trustee. 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 senior secured revolving credit facility (Revolver).

On April 25, 2012, we issued an additional $125.0 million aggregate principal amount of 9.125% Notes under the same indenture at a price of 104.0% of par, resulting in gross proceeds of $130.0 million. Net proceeds from the offering were utilized to refinance $125.0 million aggregate principal amount of the 2.125% Convertible Senior Notes due July 2012 (2.125% Notes). We repurchased $122.9 million aggregate principal amount of the 2.125% Notes tendered pursuant to a tender offer on May 9, 2012 and paid off the remaining $2.1 million at their stated maturity on July 15, 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 revenues primarily outside the United States. Interest on the 9.125% Notes is payable on April 1 and October 1 of each year. Debt issuance costs related to the 9.125% Notes of approximately $11.5 million ($8.0 million, net of amortization) are being amortized over the term of the notes using the effective interest rate method.

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 beginning April 1, 2016. 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% Notes. As noted above, on May 9, 2012, we repurchased $122.9 million aggregate principal amount of the 2.125% Notes pursuant to a tender offer. The tender offer price was $1,003.27 for each $1,000 principal amount of 2.125% Notes, plus accrued and unpaid interest. This repurchase resulted in the recording of debt extinguishment costs of $1.8 million related to the accelerated amortization of both the unamortized debt issuance costs and debt discount associated with the 2.125% Notes. The remaining $2.1 million aggregate principal amount of non-tendered 2.125% Notes was subsequently paid off at their stated maturity on July 15, 2012.

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 allowed 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 warrants allow us to sell 9,027,713 common shares at a strike price of $18.29 per share. The note hedge expired on July 15, 2012, the maturity date of the 2.125% Notes. The warrants expire ratably from October 15, 2012 to February 22, 2013.

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

Debt issuance costs related to the 2.125% Notes of approximately $3.6 million were amortized over the five year term of the 2.125% Notes using the effective interest method.

Credit Agreement:

On May 15, 2008, we entered into a credit agreement (Credit Agreement) consisting of the Revolver of $80.0 million and senior secured term loan facility (Term Loan) of up to $50.0 million. On April 1, 2011, the Company entered into an amendment to the Credit Agreement that increased the Aggregate Commitments 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, except for domestic subsidiaries owned by foreign subsidiaries and certain immaterial 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 September 30, 2012 and December 31, 2011. The Credit Agreement terminates and must be repaid on May 14, 2013. All associated obligations related to the Credit Agreement have been recorded as current liabilities in our financial statements as of September 30, 2012. Based on the current amortization schedule, the balance of the Term Loan to be repaid at maturity would be $31.0 million. Although, we believe we could repay the Term Loan at the time of maturity utilizing existing cash and cash generated from operations, it is our intention to enter into a new Credit Agreement prior to maturity.

Revolver:

Our Revolver is available for general corporate purposes and to support letters of credit. Interest on Revolver loans accrues at a Base Rate (as defined in the Credit Agreement) 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 September 30, 2012 or December 31, 2011. Letters of credit outstanding totaled $2.5 million and $2.7 million as of September 30, 2012 and December 31, 2011, respectively.

Term Loan:

The Term Loan originated at $50.0 million. On April 1, 2011, the Company expanded its Term Loan 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. Interest on the Term Loan accrues at either a Base Rate plus 2.25 percent or LIBOR plus 3.25 percent. The Term Loan requires quarterly principal payments of $6.0 million per quarter with the remaining loan balance payable upon maturity. The outstanding balance on the Term Loan at September 30, 2012 and December 31, 2011 was $43.0 million and $61.0 million, respectively.