We have no significant finance lease obligations. Debt is summarized in the following table (in thousands):


	Interest Rate	Maturity Date	March 31, 2023			December 31, 2022
2011 Senior Notes Series B (1)	4.11%	September 30, 2023	$	75,000		$	75,000
2021 Senior Notes Series A (2)	4.09%	January 12, 2026		45,000			45,000
2021 Senior Notes Series B (2)	4.38%	January 12, 2028		15,000			15,000
Credit Facility				48,000			40,000
Total long-term debt				183,000			175,000
Less: Debt issuance costs				(2,560	)		(2,614	)
Long-term debt, net			$	180,440		$	172,386

(1) Interest is payable semi-annually on March 30 and September 30.

(2) Interest is payable semi-annually on June 30 and December 30.

We, along with our wholly owned subsidiary Core Laboratories (U.S.) Interests Holdings, Inc. ("CLIH") as issuer, have three series of senior notes outstanding with an aggregate principal amount of $135 million that were issued through private placement transactions. Series B of the 2011 Senior Notes was issued in 2011 (the "2011 Senior Notes"). Series A and Series B of the 2021 Senior Notes were issued and funded in 2021 (the "2021 Senior Notes"). The 2021 Senior Notes and the 2011 Senior Notes are collectively the "Senior Notes". We intend to repay the 2011 Senior Notes Series B at maturity in September 2023 using borrowings under our existing long-term credit facility; therefore, we continue to classify them as long-term debt.

We, along with our wholly owned subsidiary CLIH, have a credit facility, the Eighth Amended and Restated Credit Agreement (as amended, the "Credit Facility") for an aggregate borrowing commitment of $135 million with a $50 million “accordion” feature. The Credit Facility is secured by first priority interests in (1) substantially all of the tangible and intangible personal property, and equity interest of CLIH and certain of the Company's U.S. and foreign subsidiary companies; and (2) instruments evidencing intercompany indebtedness owing to the Company, CLIH and certain of the Company's U.S. and foreign subsidiary companies. Under the Credit Facility, the Secured Overnight Financing Rate ("SOFR") plus 2.00% to SOFR plus 3.00% will be applied to outstanding borrowings. Any outstanding balance under the Credit Facility is due at maturity on July 25, 2026, subject to springing maturity on July 12, 2025, if any portion of the Company’s 2021 Senior Notes Series A due January 12, 2026, in the aggregate principal amount of $45 million, remain outstanding on July 12, 2025, unless the Company's liquidity equals or exceeds the principal amount of the 2021 Senior Notes Series A outstanding on such date. The available capacity at any point in time is reduced by outstanding borrowings and outstanding letters of credit which totaled approximately $9 million at March 31, 2023, resulting in an available borrowing capacity under the Credit Facility of approximately $78 million. In addition to indebtedness under the Credit Facility, we had approximately $6 million of outstanding letters of credit and performance guarantees and bonds from other sources as of March 31, 2023.

The terms of the Credit Facility and Senior Notes require us to meet certain covenants, including, but not limited to, an interest coverage ratio (calculated as consolidated EBITDA divided by interest expense) and a leverage ratio (calculated as consolidated net indebtedness divided by consolidated EBITDA), where consolidated EBITDA (as defined in each agreement) and interest expense are calculated using the most recent four fiscal quarters. The Credit Facility and Senior Notes include a cross-default provision, whereby a default under one agreement may trigger a default in the other agreements. The Credit Facility has more restrictive covenants with a minimum interest coverage ratio of 3.00 to 1.00 and permits a maximum leverage ratio of 2.50 to 1.00. The Credit Facility allows non-cash charges such as impairment of assets, stock compensation and other non-cash charges to be added back in the calculation of consolidated EBITDA. The terms of our Credit Facility also allow us to negotiate in good faith to amend any ratio or requirement to preserve the original intent of the agreement if any change in accounting principles would affect the computation of any financial ratio or covenant of the Credit Facility. In accordance with the terms of the Credit Facility, our leverage ratio is 2.18, and our interest coverage ratio is 6.20, each for the period ended

March 31, 2023. We believe that we are in compliance with all covenants contained in our Credit Facility and Senior Notes. Certain of our material, wholly owned subsidiaries are guarantors or co-borrowers under the Credit Facility and Senior Notes.

See Note 11 - Derivative Instruments and Hedging Activities for additional information regarding interest rate swap agreements we have entered to fix the underlying risk-free rate on our Credit Facility and long-term debt.

The estimated fair value of total debt at March 31, 2023, and December 31, 2022, approximated the book value of total debt. The fair value was estimated using Level 2 inputs by calculating the sum of the discounted future interest and principal payments through the maturity date.