General Information	12 Months Ended
Dec. 31, 2022
Accounting Policies [Abstract]
General Information	1. General Information Diamond Offshore Drilling, Inc. provides contract drilling services to the energy industry around the globe with a fleet of 14 offshore drilling rigs, consisting of four owned drillships, eight owned semisubmersible rigs and two managed rigs. Unless the context otherwise requires, references in these Notes to “Diamond Offshore,” “we,” “us” or “our” mean Diamond Offshore Drilling, Inc. and our consolidated subsidiaries. We were incorporated in Delaware in 1989. To facilitate our financial statement presentations, we refer to the post-emergence reorganized company in these Consolidated Financial Statements and footnotes as the “Successor” for periods subsequent to April 23, 2021 and to the pre-emergence company as the “Predecessor” for periods on or prior to April 23, 2021. This delineation between Predecessor periods and Successor periods is shown in the Consolidated Financial Statements, certain tables within the footnotes to the Consolidated Financial Statements and other parts of this Annual Report on Form 10-K through the use of a black line, calling out the lack of comparability between periods. Principles of Consolidation Our Consolidated Financial Statements include the accounts of Diamond Offshore Drilling, Inc. and our wholly-owned subsidiaries after elimination of intercompany transactions and balances. Use of Estimates in the Preparation of Financial Statements The preparation of financial statements in conformity with accounting principles generally accepted in the United States (or U.S.), or GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amount of revenues and expenses during the reporting period. Actual results could differ from those estimated. Cash and Cash Equivalents We consider short-term, highly liquid investments that have an original maturity of three months or less and deposits in money market mutual funds that are readily convertible into cash to be cash equivalents. The effect of exchange rate changes on cash balances held in foreign currencies was not material for the Successor periods for the year ended December 31, 2022 and from April 24, 2021 through December 31, 2021 and the Predecessor period from January 1, 2021 through April 23, 2021. Asset Held for Sale We reported the $1.0 million carrying value of the Ocean Valor, as “Asset held for sale” in our Successor Consolidated Balance Sheet at December 31, 2021. The rig was sold in February 2022 at a net pre-tax gain of approximately $4.0 million. Drilling and Other Property and Equipment We carry our drilling and other property and equipment at cost, less accumulated depreciation. Maintenance and routine repairs are charged to income while replacements and betterments that upgrade or increase the functionality of our existing equipment and that significantly extend the useful life of an existing asset are capitalized. Significant judgments, assumptions and estimates may be required in determining whether or not such replacements and betterments meet the criteria for capitalization and in determining useful lives and salvage values of such assets. Changes in these judgments, assumptions and estimates could produce results that differ from those reported. During the Successor periods for the year ended December 31, 2022 and from April 24, 2021 through December 31, 2021 and the Predecessor period from January 1, 2021 through April 23, 2021, we capitalized $69.1 million, $22.0 million and $59.9 million, respectively, in replacements and betterments of our drilling fleet. Costs incurred for major rig upgrades and/or the construction of rigs are accumulated in construction work-in-progress, with no depreciation recorded on the additions, until the month the upgrade or newbuild is completed and the rig is placed in service. Upon retirement or sale of a rig, the cost and related accumulated depreciation are removed from the respective accounts and any gains or losses are reported in our Consolidated Statements of Operations as “(Gain) loss on disposition of assets.” Depreciation is recognized up to applicable salvage values by applying the straight-line method over the remaining estimated useful lives from the year the asset is placed in service. Drilling rigs and equipment are depreciated over their estimated useful lives ranging from 3 to 30 years. Impairment of Long-Lived Assets We evaluate our property and equipment for impairment whenever changes in circumstances indicate that the carrying amount of an asset may not be recoverable (such as, but not limited to, a change in the economic useful life of a rig, cold stacking a rig, the expectation of cold stacking a rig in the near term, a decision to retire or scrap a rig, or excess spending over budget on a newbuild, construction project, reactivation or major rig upgrade). We utilize an undiscounted probability-weighted cash flow analysis in testing an asset for potential impairment. Our assumptions and estimates underlying this analysis include the following: • dayrate by rig; • utilization rate by rig if active, warm-stacked or cold-stacked (expressed as the actual percentage of time per year that the rig would be used at certain dayrates); • the per day operating cost for each rig if active, warm-stacked or cold-stacked; • the estimated annual cost for rig replacements and/or enhancement programs; • the estimated maintenance and inspection or other reactivation costs associated with a rig returning to work; • the remaining economic useful life of a rig; • salvage value for each rig; and • estimated proceeds that may be received on disposition of each rig. Based on these assumptions, we develop a matrix for each rig under evaluation using multiple utilization/dayrate scenarios, to each of which we have assigned a probability of occurrence. We arrive at a projected probability-weighted cash flow for each rig based on the respective matrix and compare such amount to the carrying value of the asset to assess recoverability. The underlying assumptions and assigned probabilities of occurrence for utilization and dayrate scenarios are developed using a methodology that examines historical data for each rig, which considers the rig’s age, rated water depth and other attributes and then assesses its future marketability in light of the current and projected market environment at the time of assessment. Other assumptions, such as operating, maintenance, inspection and reactivation costs, are estimated using historical data adjusted for known developments, cost projections for re-entry of rigs into the market and future events that are anticipated by management at the time of the assessment. Management’s assumptions are necessarily subjective and are an inherent part of our asset impairment evaluation, and the use of different assumptions could produce results that differ from those reported. Our methodology generally involves the use of significant unobservable inputs, representative of a Level 3 fair value measurement, which may include assumptions related to future dayrate revenue, costs and rig utilization, quotes from rig brokers, the long-term future performance of our rigs and future market conditions. Management’s assumptions involve uncertainties about future demand for our services, dayrates, expenses and other future events, and management’s expectations may not be indicative of future outcomes. Significant unanticipated changes to these assumptions could materially alter our analysis in testing an asset for potential impairment. For example, changes in market conditions that exist at the measurement date or that are projected by management could affect our key assumptions. Other events or circumstances that could affect our assumptions may include, but are not limited to, a further sustained decline in oil and gas prices, cancellations of our drilling contracts or contracts of our competitors, contract modifications, costs to comply with new governmental regulations, capital expenditures required due to advances in offshore drilling technology, growth in the global oversupply of oil and geopolitical events, such as lifting sanctions on oil-producing nations. Should actual market conditions in the future vary significantly from market conditions used in our projections, our assessment of impairment would likely be different. See Note 5 “Asset Impairments.” Survey Costs Concurrent with emergence from bankruptcy, the Successor entity adopted a new policy providing for the deferral and amortization of costs associated with planned periodic inspections of its drilling rigs (or vessels) to ensure compliance with applicable regulations and maintain certifications for vessels with classification societies that typically occur on five-year or two-and-one-half year intervals. These costs include mobilization of the vessel into the shipyard, drydocking, support services while in shipyard and the associated survey or inspection costs necessary to maintain class certifications. These recertification costs are typically incurred while the vessel is in drydock and may be performed concurrent with other vessel maintenance and improvement activities. Costs related to the recertification of vessels are deferred and amortized over the survey interval on a straight-line basis. Maintenance costs incurred at the time of the recertification drydocking, which are not related to the recertification of the vessel are expensed as incurred. Costs for vessel improvements which either extend the vessel’s useful life or increase the vessel's functionality are capitalized and depreciated. The Predecessor’s previous policy was to expense vessel recertification costs in the period incurred. For the Successor periods for the year ended December 31, 2022 and from April 24, 2021 through December 31, 2021, we deferred $3.3 million and $0.9 million, respectively, in survey costs. At December 31, 2022 and 2021, deferred survey costs of $0.8 million and $0.5 million, respectively, were reported in “Prepaid expenses and other current assets” and $2.5 million and $0.2 million, respectively, were reported in “Other assets” in our Successor Consolidated Balance Sheets. We amortized $0.7 million and $0.2 million in deferred survey costs as “Contract drilling, excluding depreciation” in the Successor’s Consolidated Statements of Operations for the year ended December 31, 2022 and the period from April 24, 2021 through December 31, 2021. Lease Accounting and Revenue Recognition Financial Accounting Standards Board (or FASB) Accounting Standards Update (or ASU), No. 2016-02, Leases (Topic 842) (ASU 2016-02), requires lessees to recognize a right of use asset and a lease liability on the balance sheet for most leases. Upon adoption of ASU 2016-02, we concluded that our drilling contracts contain a lease component for the use of our drilling rigs based on the updated definition of a lease. However, ASU 2016-02 provides for a practical expedient for lessors whereby, under certain circumstances, the lessor may combine the lease and non-lease components and account for the combined component in accordance with the accounting treatment for the predominant component. We have determined that our current drilling contracts qualify for this practical expedient and have combined the lease and service components of our standard drilling contracts. We continue to account for the combined component under FASB ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) and its related amendments (collectively referred to as Topic 606). Fair Value of Financial Instruments We believe that the carrying amount of our current financial instruments approximates fair value because of the short maturity of these instruments. See Note 9 “Financial Instruments and Fair Value Disclosures.” Debt Issuance Costs Deferred costs associated with our credit facility are presented in “Other assets” in the Successor's Consolidated Balance Sheets at December 31, 2022 and 2021 and amortized as interest expense over the respective terms of the credit facility. Deferred costs associated with our other long-term debt are presented in the Successor's Consolidated Balance Sheets at December 31, 2022 and 2021 as a reduction in the related long-term debt and are amortized over the respective terms of the related debt as interest expense. See Note 2 “Chapter 11 Proceedings” and Note 11 “Prepetition Revolving Credit Facility, Senior Notes and Exit Debt” for a discussion of deferred arrangement fees associated with our Successor and Predecessor credit facilities and long-term debt. Income Taxes We account for income taxes in accordance with accounting standards that require the recognition of the amount of taxes payable or refundable for the current year and an asset and liability approach in recognizing the amount of deferred tax liabilities and assets for the future tax consequences of events that have been currently recognized in our financial statements or tax returns. In each of our tax jurisdictions we recognize a current tax liability or asset for the estimated taxes payable or refundable on tax returns for the current year and a deferred tax asset or liability for the estimated future tax effects attributable to temporary differences and carryforwards. Deferred tax assets are reduced by a valuation allowance, if necessary, which is determined by the amount of any tax benefits that, based on available evidence, are not expected to be realized under a “more likely than not” approach. Deferred tax assets and liabilities are classified as noncurrent in a classified statement of financial position. We make judgments regarding future events and related estimates especially as they pertain to the forecasting of our effective tax rate, the potential realization of deferred tax assets such as utilization of foreign tax credits, and exposure to the disallowance of items deducted on tax returns upon audit. We record both interest and penalties related to accrued uncertain tax positions in “Income tax benefit (expense)” in our Consolidated Statements of Operations. Liabilities for uncertain tax positions, including any interest and penalties, are denominated in the currency of the related tax jurisdiction and are revalued for changes in currency exchange rates. The revaluation of such liabilities for uncertain tax positions is reported in “Income tax benefit (expense)” in our Consolidated Statements of Operations. See Note 16 “Income Taxes.” Comprehensive Loss Comprehensive (loss) income is the change in equity of a business enterprise during a period from transactions and other events and circumstances except those transactions resulting from investments by owners and distributions to owners. Comprehensive loss for the Successor periods for the year ended December 31, 2022 and from April 24, 2021 through December 31, 2021 and the Predecessor periods from January 1, 2021 through April 23, 2021 and the year ended December 31, 2020 includes net losses and unrealized holding gains and losses on marketable securities and financial derivatives designated as cash flow accounting hedges. Foreign Currency Our functional currency is the U.S. dollar. Transactions incurred in currencies other than the U.S. dollar are subject to gains or losses due to fluctuations in those currencies. We report foreign currency transaction gains and losses as “Foreign currency transaction loss” in our Consolidated Statements of Operations. The revaluation of assets and liabilities related to foreign income taxes, including deferred tax assets and liabilities and uncertain tax positions, including any interest and/or penalties, is reported in “Income tax (expense) benefit” in our Consolidated Statements of Operations.

General Information

12 Months Ended

Dec. 31, 2022

1. General Information

Diamond Offshore Drilling, Inc. provides contract drilling services to the energy industry around the globe with a fleet of 14 offshore drilling rigs, consisting of four owned drillships, eight owned semisubmersible rigs and two managed rigs.

Unless the context otherwise requires, references in these Notes to “Diamond Offshore,” “we,” “us” or “our” mean Diamond Offshore Drilling, Inc. and our consolidated subsidiaries. We were incorporated in Delaware in 1989. To facilitate our financial statement presentations, we refer to the post-emergence reorganized company in these Consolidated Financial Statements and footnotes as the “Successor” for periods subsequent to April 23, 2021 and to the pre-emergence company as the “Predecessor” for periods on or prior to April 23, 2021. This delineation between Predecessor periods and Successor periods is shown in the Consolidated Financial Statements, certain tables within the footnotes to the Consolidated Financial Statements and other parts of this Annual Report on Form 10-K through the use of a black line, calling out the lack of comparability between periods.

Principles of Consolidation

Our Consolidated Financial Statements include the accounts of Diamond Offshore Drilling, Inc. and our wholly-owned subsidiaries after elimination of intercompany transactions and balances.

Use of Estimates in the Preparation of Financial Statements

The preparation of financial statements in conformity with accounting principles generally accepted in the United States (or U.S.), or GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amount of revenues and expenses during the reporting period. Actual results could differ from those estimated.

Cash and Cash Equivalents

We consider short-term, highly liquid investments that have an original maturity of three months or less and deposits in money market mutual funds that are readily convertible into cash to be cash equivalents.

The effect of exchange rate changes on cash balances held in foreign currencies was not material for the Successor periods for the year ended December 31, 2022 and from April 24, 2021 through December 31, 2021 and the Predecessor period from January 1, 2021 through April 23, 2021.

Asset Held for Sale

We reported the $1.0 million carrying value of the Ocean Valor, as “Asset held for sale” in our Successor Consolidated Balance Sheet at December 31, 2021. The rig was sold in February 2022 at a net pre-tax gain of approximately $4.0 million.

Drilling and Other Property and Equipment

We carry our drilling and other property and equipment at cost, less accumulated depreciation. Maintenance and routine repairs are charged to income while replacements and betterments that upgrade or increase the functionality of our existing equipment and that significantly extend the useful life of an existing asset are capitalized. Significant judgments, assumptions and estimates may be required in determining whether or not such replacements and betterments meet the criteria for capitalization and in determining useful lives and salvage values of such assets.

Changes in these judgments, assumptions and estimates could produce results that differ from those reported. During the Successor periods for the year ended December 31, 2022 and from April 24, 2021 through December 31, 2021 and the Predecessor period from January 1, 2021 through April 23, 2021, we capitalized $69.1 million, $22.0 million and $59.9 million, respectively, in replacements and betterments of our drilling fleet.

Costs incurred for major rig upgrades and/or the construction of rigs are accumulated in construction work-in-progress, with no depreciation recorded on the additions, until the month the upgrade or newbuild is completed and the rig is placed in service. Upon retirement or sale of a rig, the cost and related accumulated depreciation are removed from the respective accounts and any gains or losses are reported in our Consolidated Statements of Operations as “(Gain) loss on disposition of assets.” Depreciation is recognized up to applicable salvage values by applying the straight-line method over the remaining estimated useful lives from the year the asset is placed in service. Drilling rigs and equipment are depreciated over their estimated useful lives ranging from 3 to 30 years.

Impairment of Long-Lived Assets

We evaluate our property and equipment for impairment whenever changes in circumstances indicate that the carrying amount of an asset may not be recoverable (such as, but not limited to, a change in the economic useful life of a rig, cold stacking a rig, the expectation of cold stacking a rig in the near term, a decision to retire or scrap a rig, or excess spending over budget on a newbuild, construction project, reactivation or major rig upgrade). We utilize an undiscounted probability-weighted cash flow analysis in testing an asset for potential impairment. Our assumptions and estimates underlying this analysis include the following:

•

dayrate by rig;

•

utilization rate by rig if active, warm-stacked or cold-stacked (expressed as the actual percentage of time per year that the rig would be used at certain dayrates);

•

the per day operating cost for each rig if active, warm-stacked or cold-stacked;

•

the estimated annual cost for rig replacements and/or enhancement programs;

•

the estimated maintenance and inspection or other reactivation costs associated with a rig returning to work;

•

the remaining economic useful life of a rig;

•

salvage value for each rig; and

•

estimated proceeds that may be received on disposition of each rig.

Based on these assumptions, we develop a matrix for each rig under evaluation using multiple utilization/dayrate scenarios, to each of which we have assigned a probability of occurrence. We arrive at a projected probability-weighted cash flow for each rig based on the respective matrix and compare such amount to the carrying value of the asset to assess recoverability.

The underlying assumptions and assigned probabilities of occurrence for utilization and dayrate scenarios are developed using a methodology that examines historical data for each rig, which considers the rig’s age, rated water depth and other attributes and then assesses its future marketability in light of the current and projected market environment at the time of assessment. Other assumptions, such as operating, maintenance, inspection and reactivation costs, are estimated using historical data adjusted for known developments, cost projections for re-entry of rigs into the market and future events that are anticipated by management at the time of the assessment.

Management’s assumptions are necessarily subjective and are an inherent part of our asset impairment evaluation, and the use of different assumptions could produce results that differ from those reported. Our methodology generally involves the use of significant unobservable inputs, representative of a Level 3 fair value measurement, which may include assumptions related to future dayrate revenue, costs and rig utilization, quotes from rig brokers, the long-term future performance of our rigs and future market conditions. Management’s assumptions involve uncertainties about future demand for our services, dayrates, expenses and other future events, and management’s expectations may not be indicative of future outcomes. Significant unanticipated changes to these assumptions could materially alter our analysis in testing an asset for potential impairment. For example, changes in market conditions that exist at the

measurement date or that are projected by management could affect our key assumptions. Other events or circumstances that could affect our assumptions may include, but are not limited to, a further sustained decline in oil and gas prices, cancellations of our drilling contracts or contracts of our competitors, contract modifications, costs to comply with new governmental regulations, capital expenditures required due to advances in offshore drilling technology, growth in the global oversupply of oil and geopolitical events, such as lifting sanctions on oil-producing nations. Should actual market conditions in the future vary significantly from market conditions used in our projections, our assessment of impairment would likely be different. See Note 5 “Asset Impairments.”

Survey Costs

Concurrent with emergence from bankruptcy, the Successor entity adopted a new policy providing for the deferral and amortization of costs associated with planned periodic inspections of its drilling rigs (or vessels) to ensure compliance with applicable regulations and maintain certifications for vessels with classification societies that typically occur on five-year or two-and-one-half year intervals. These costs include mobilization of the vessel into the shipyard, drydocking, support services while in shipyard and the associated survey or inspection costs necessary to maintain class certifications. These recertification costs are typically incurred while the vessel is in drydock and may be performed concurrent with other vessel maintenance and improvement activities. Costs related to the recertification of vessels are deferred and amortized over the survey interval on a straight-line basis. Maintenance costs incurred at the time of the recertification drydocking, which are not related to the recertification of the vessel are expensed as incurred. Costs for vessel improvements which either extend the vessel’s useful life or increase the vessel's functionality are capitalized and depreciated. The Predecessor’s previous policy was to expense vessel recertification costs in the period incurred.

For the Successor periods for the year ended December 31, 2022 and from April 24, 2021 through December 31, 2021, we deferred $3.3 million and $0.9 million, respectively, in survey costs. At December 31, 2022 and 2021, deferred survey costs of $0.8 million and $0.5 million, respectively, were reported in “Prepaid expenses and other current assets” and $2.5 million and $0.2 million, respectively, were reported in “Other assets” in our Successor Consolidated Balance Sheets. We amortized $0.7 million and $0.2 million in deferred survey costs as “Contract drilling, excluding depreciation” in the Successor’s Consolidated Statements of Operations for the year ended December 31, 2022 and the period from April 24, 2021 through December 31, 2021.

Lease Accounting and Revenue Recognition

Financial Accounting Standards Board (or FASB) Accounting Standards Update (or ASU), No. 2016-02, Leases (Topic 842) (ASU 2016-02), requires lessees to recognize a right of use asset and a lease liability on the balance sheet for most leases. Upon adoption of ASU 2016-02, we concluded that our drilling contracts contain a lease component for the use of our drilling rigs based on the updated definition of a lease. However, ASU 2016-02 provides for a practical expedient for lessors whereby, under certain circumstances, the lessor may combine the lease and non-lease components and account for the combined component in accordance with the accounting treatment for the predominant component. We have determined that our current drilling contracts qualify for this practical expedient and have combined the lease and service components of our standard drilling contracts. We continue to account for the combined component under FASB ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) and its related amendments (collectively referred to as Topic 606).

Fair Value of Financial Instruments

We believe that the carrying amount of our current financial instruments approximates fair value because of the short maturity of these instruments. See Note 9 “Financial Instruments and Fair Value Disclosures.”

Debt Issuance Costs

Deferred costs associated with our credit facility are presented in “Other assets” in the Successor's Consolidated Balance Sheets at December 31, 2022 and 2021 and amortized as interest expense over the respective terms of the credit facility. Deferred costs associated with our other long-term debt are presented in the Successor's Consolidated

Balance Sheets at December 31, 2022 and 2021 as a reduction in the related long-term debt and are amortized over the respective terms of the related debt as interest expense.

See Note 2 “Chapter 11 Proceedings” and Note 11 “Prepetition Revolving Credit Facility, Senior Notes and Exit Debt” for a discussion of deferred arrangement fees associated with our Successor and Predecessor credit facilities and long-term debt.

Income Taxes

We account for income taxes in accordance with accounting standards that require the recognition of the amount of taxes payable or refundable for the current year and an asset and liability approach in recognizing the amount of deferred tax liabilities and assets for the future tax consequences of events that have been currently recognized in our financial statements or tax returns. In each of our tax jurisdictions we recognize a current tax liability or asset for the estimated taxes payable or refundable on tax returns for the current year and a deferred tax asset or liability for the estimated future tax effects attributable to temporary differences and carryforwards. Deferred tax assets are reduced by a valuation allowance, if necessary, which is determined by the amount of any tax benefits that, based on available evidence, are not expected to be realized under a “more likely than not” approach. Deferred tax assets and liabilities are classified as noncurrent in a classified statement of financial position. We make judgments regarding future events and related estimates especially as they pertain to the forecasting of our effective tax rate, the potential realization of deferred tax assets such as utilization of foreign tax credits, and exposure to the disallowance of items deducted on tax returns upon audit.

We record both interest and penalties related to accrued uncertain tax positions in “Income tax benefit (expense)” in our Consolidated Statements of Operations. Liabilities for uncertain tax positions, including any interest and penalties, are denominated in the currency of the related tax jurisdiction and are revalued for changes in currency exchange rates. The revaluation of such liabilities for uncertain tax positions is reported in “Income tax benefit (expense)” in our Consolidated Statements of Operations. See Note 16 “Income Taxes.”

Comprehensive Loss

Comprehensive (loss) income is the change in equity of a business enterprise during a period from transactions and other events and circumstances except those transactions resulting from investments by owners and distributions to owners. Comprehensive loss for the Successor periods for the year ended December 31, 2022 and from April 24, 2021 through December 31, 2021 and the Predecessor periods from January 1, 2021 through April 23, 2021 and the year ended December 31, 2020 includes net losses and unrealized holding gains and losses on marketable securities and financial derivatives designated as cash flow accounting hedges.

Foreign Currency

Our functional currency is the U.S. dollar. Transactions incurred in currencies other than the U.S. dollar are subject to gains or losses due to fluctuations in those currencies. We report foreign currency transaction gains and losses as “Foreign currency transaction loss” in our Consolidated Statements of Operations. The revaluation of assets and liabilities related to foreign income taxes, including deferred tax assets and liabilities and uncertain tax positions, including any interest and/or penalties, is reported in “Income tax (expense) benefit” in our Consolidated Statements of Operations.