Select Water : Changes to Segment Reporting & Recast Financial Information

Cautionary Statement Regarding Forward Looking Statements

This presentation, including the oral statements made in connection herewith, contains certain statements and information that may constitute "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. All statements, other than statements of historical fact, regarding Select Water Solutions, Inc.'s ("Select" or the "Company") current expectations about its future results, including, but not limited to, statements about its strategy, future operations, financial position, estimated revenues and losses, projected costs, prospects, plans and objectives of Select's management, are forward-looking statements. When used in this presentation, the words "could," "believe," "estimate," "expect," "may," "project," "will," and similar expressions or variations are intended to identify forward-looking statements, although not all forward-looking statements contain such identifying words. These forward-looking statements are based on current expectations and assumptions of Select's management about future events and are based on currently available information as to the outcome and timing of future events. Although we believe that the expectations reflected, and the assumptions or bases underlying our forward-looking statements are reasonable under the circumstances, we can give no assurance that such expectations will prove to be correct. Such statements are not guarantees of future performance or events and are subject to known and unknown risks and uncertainties that could cause our actual results, events or financial positions to differ materially from those included within or implied by such forward-looking statements. These risks and uncertainties include the risks that the benefits contemplated from our recent acquisitions may not be realized, the ability of Select to successfully integrate the acquired businesses' operations, including employees, and realize anticipated synergies and cost savings and the potential impact of the consummation of the acquisitions on relationships, including with employees, suppliers, customers, competitors and creditors. Accordingly, investors should not place undue reliance on forward-looking statements as a prediction of actual results. Each forward-looking statement in this presentation speaks only as of the date of this presentation. Except as required by applicable law, Select

disclaims any intention or obligation to revise or update any forward- looking statements contained in this presentation.

Factors that could cause our actual results to differ materially from the results contemplated by such forward-looking statements include, but are not limited to, the global macroeconomic uncertainty related to the Russia-Ukraine war; central bank policy actions, bank failures and associated liquidity risks and other factors; actions by the members of OPEC+ with respect to oil production levels and announcements of potential changes in such levels, including the ability of the OPEC+ countries to agree on and comply with supply limitations; the severity and duration of world health events; the level of capital spending and access to capital markets by oil and gas companies, trends and volatility in oil and gas prices, and our ability to manage through such volatility; and other factors discussed or referenced in the "Risk Factors" section of our Annual Report on Form 10-K (our "Form 10-K") and our other filings with the U.S. Securities and Exchange Commission (the "SEC"). There may be other factors of which Select is currently unaware or deems immaterial that may cause its actual results to differ materially from the forward- looking statements. The information contained in this presentation has not been independently verified other than by the Company and no representation or warranty, express or implied, is made as to the fairness, accuracy, completeness or correctness of the information contained herein and no reliance should be placed on it.

Additional Information and Where to Find It

For additional information regarding Select, please see our Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, which are available at no charge at the SEC's website, http://www.sec.gov, and our website at https://investors.selectenergy.com/sec-filings. In addition, documents will also be available for free from the Company by contacting the Company at 1233 W Loop S, Suite 1400, Houston, TX 77027 or (713) 235-9500. The contents of the website references in this presentation are not incorporated herein by reference.

Non-GAAP Financial Measures

Gross profit before depreciation and amortization ("D&A") and gross margin before D&A are not financial measures presented in accordance with U.S. generally accepted accounting principles ("GAAP"). We define gross profit before D&A as revenue less cost of revenue, excluding cost of sales D&A expense. We define gross margin before D&A as gross profit before D&A divided by revenue. Gross profit before D&A and gross margin before D&A are supplemental non-GAAP financial measures that we believe provide useful information to external users of our financial statements, such as industry analysts, investors, lenders and rating agencies because it allows them to compare our operating performance on a consistent basis across periods by removing the effects of our asset base (such as depreciation and amortization). We present gross profit before D&A and gross margin before D&A because we believe they provide useful information to our investors and market participants regarding the factors and trends affecting our business in addition to measures calculated under GAAP.

Gross profit is the GAAP measure most directly comparable to gross profit before D&A. Our non-GAAP financial measures should not be considered as alternatives to the most directly comparable GAAP financial measure. Each of these non-GAAP financial measures has important limitations as an analytical tool due to exclusion of some but not all items that affect the most directly comparable GAAP financial measures. You should not consider gross profit before D&A or gross margin before D&A in isolation or as substitutes for an analysis of our results as reported under GAAP. Because gross profit before D&A or gross margin before D&A may be defined differently by other companies in our industry, our definitions of these non-GAAP financial measures may not be comparable to similarly titled measures of other companies, thereby diminishing their utility. For further discussion, please see our Form 10-K and our latest Quarterly Report on Form 10-Q. For a reconciliation of these non-GAAP measures presented on a historical basis, please see the tables in the Appendix at the end of this presentation.

Prior Segmentation

New Segmentation

Water Services

• Water Transfer
• Water Containment
• Water Monitoring
• Flowback & Well Testing
• Fluid Hauling
• Accommodations & Rentals

Water Infrastructure

• Water Sourcing
• Water Logistics
• Water Recycling & Reuse
• Gathering & Distribution Pipelines
• Fluid Disposals

Moved to

Water Services

Water Services

• Water Sourcing
• Water Transfer (& Logistics)
• Water Containment
• Water Monitoring
• Flowback & Well Testing
• Fluid Hauling
• Accommodations & Rentals

Water Infrastructure

• Water Recycling & Reuse
• Gathering & Distribution Pipelines
• Fluid Disposals

Oilfield Chemicals

• Chemical Manufacturing
• Completion Chemicals
• Water Treatment

Chemical

Technologies

• Chemical Manufacturing
• Completion Chemicals
• Water Treatment

Notes:

1. Values shown reflect new segment reporting structure
2. Gross Profit before D&A is a Non-GAAP financial measure, see Disclaimer on page 2 for important disclosures regarding non-GAAP financial measures & the Appendix for reconciliation detail
3. 2018 includes preliminary estimated allocations of intercompany eliminations & other items. The Company expects to provide additional historical recast information in subsequent materials
4. Wellsite Services operations were divested during 2019
5. Q3 Projected based off of midpoint of segment by segment guidance, where applicable

Expected to increase to 50%+ in 2024

5