February 27, Fourth Quarter and Full-Year 2018 Results Earnings Conference Call

February 27, 2019 Fourth Quarter and Full-Year 2018 Results Earnings Conference Call

Non-GAAP Financial Measures SemGroup s non-gaap measures, Adjusted EBITDA, Cash Available for Dividends (CAFD) and Total Segment Profit, are not GAAP measures and are not intended to be used in lieu of GAAP presentation of their most closely associated GAAP measures, net income (loss) for Adjusted EBITDA and CAFD and operating income for Total Segment Profit. Adjusted EBITDA represents earnings before interest, taxes, depreciation and amortization, adjusted for selected items that SemGroup believes impact the comparability of financial results between reporting periods. In addition to non-cash items, we have selected items for adjustment to EBITDA which management feels decrease the comparability of our results among periods. These items are identified as those which are generally outside of the results of day to day operations of the business. These items are not considered nonrecurring, infrequent or unusual, but do erode comparability among periods in which they occur with periods in which they do not occur or occur to a greater or lesser degree. Historically, we have selected items such as gains on the sale of NGL Energy Partners LP common units, costs related to our predecessor s bankruptcy, significant business development related costs, significant legal settlements, severance and other similar costs. Management believes these types of items can make comparability of the results of day to day operations among periods difficult and have chosen to remove these items from our Adjusted EBITDA. We expect to adjust for similar types of items in the future. Although we present selected items that we consider in evaluating our performance, you should be aware that the items presented do not represent all items that affect comparability between the periods presented. Variations in our operating results are also caused by changes in volumes, prices, mechanical interruptions and numerous other factors. We do not adjust for these types of variances. CAFD is based on Adjusted EBITDA, as defined above, and reduced for cash income taxes, cash interest expense, preferred stock cash dividends and maintenance capital expenditures, as adjusted for selected items which management feels decrease the comparability of results among periods. CAFD is a performance measure utilized by management to analyze our performance after the payment of cash taxes, servicing debt obligations and making sustaining capital expenditures. Total Segment Profit represents revenue, less cost of products sold (exclusive of depreciation and amortization) and operating expenses, plus equity earnings and is adjusted to remove unrealized gains and losses on commodity derivatives and to reflect equity earnings on an EBITDA basis. Reflecting equity earnings on an EBITDA basis is achieved by adjusting equity earnings to exclude our percentage of interest, taxes, depreciation and amortization from equity earnings for operated equity method investees. For our investment in NGL Energy, we exclude equity earnings and include cash distributions received. Segment profit is the measure by which management assess the performance of our reportable segments. These measures may be used periodically by management when discussing our financial results with investors and analysts and are presented as management believes they provide additional information and metrics relative to the performance of our businesses. These non-gaap financial measures have important limitations as analytical tools because they exclude some, but not all, items that affect the most directly comparable GAAP financial measures. You should not consider non-gaap measures in isolation or as substitutes for analysis of our results as reported under GAAP. Management compensates for the limitations of our non-gaap measures as analytical tools by reviewing the comparable GAAP measures, understanding the differences between the non-gaap measure and the most comparable GAAP measure and incorporating this knowledge into its decision-making processes. We believe that investors benefit from having access to the same financial measures that our management uses in evaluating our operating results. Because all companies do not use identical calculations, our presentations of non-gaap measures may be different from similarly titled measures of other companies, thereby diminishing their utility. SemGroup does not provide guidance for net income, the GAAP financial measure most directly comparable to the non-gaap financial measure Adjusted EBITDA, because Net Income includes items such as unrealized gains or losses on derivative activities or similar items which, because of their nature, cannot be accurately forecasted. We do not expect that such amounts would be significant to Adjusted EBITDA as they are largely non-cash items. 2

Forward-Looking Information Certain matters contained in this Presentation include 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. We make these forward-looking statements in reliance on the safe harbor protections provided under the Private Securities Litigation Reform Act of 1995. All statements, other than statements of historical fact, included in this presentation including the prospects of our industry, our anticipated financial performance, our anticipated annual dividend growth rate, management's plans and objectives for future operations, planned capital expenditures, business prospects, outcome of regulatory proceedings, market conditions, and other matters, may constitute forward-looking statements. Although we believe that the expectations reflected in these forward-looking statements are reasonable, we cannot assure you that these expectations will prove to be correct. These forward-looking statements are subject to certain known and unknown risks and uncertainties, as well as assumptions that could cause actual results to differ materially from those reflected in these forward-looking statements. Factors that might cause actual results to differ include, but are not limited to, our ability to generate sufficient cash flow from operations to enable us to pay our debt obligations and our current and expected dividends or to fund our other liquidity needs; any sustained reduction in demand for, or supply of, the petroleum products we gather, transport, process, market and store; the effect of our debt level on our future financial and operating flexibility, including our ability to obtain additional capital on terms that are favorable to us; our ability to access the debt and equity markets, which will depend on general market conditions and the credit ratings for our debt obligations and equity; the loss of, or a material nonpayment or nonperformance by, any of our key customers; the amount of cash distributions, capital requirements and performance of our investments and joint ventures; the consequences of any divestitures of non-strategic operating assets or divestitures of interests in some of our operating assets through partnerships and/or join ventures; the failure to realize the anticipated benefits of our acquisition of Meritage Midstream ULC and its midstream infrastructure assets through our joint venture SemCAMS Midstream ULC; the amount of collateral required to be posted from time to time in our commodity purchase, sale or derivative transactions; the impact of operational and developmental hazards and unforeseen interruptions; our ability to obtain new sources of supply of petroleum products; competition from other midstream energy companies; our ability to comply with the covenants contained in our credit agreements, continuing covenant agreement, and the indentures governing our notes, including requirements under our credit agreements and continuing covenant agreement to maintain certain financial ratios; our ability to renew or replace expiring storage, transportation and related contracts; the overall forward markets for crude oil, natural gas and natural gas liquids; the possibility that the construction or acquisition of new assets may not result in the corresponding anticipated revenue increases; any future impairment of goodwill resulting from the loss of customers or business; changes in currency exchange rates; weather and other natural phenomena, including climate conditions; a cyber attack involving our information systems and related infrastructure, or that of our business associates; the risks and uncertainties of doing business outside of the U.S., including political and economic instability and changes in local governmental laws, regulations and policies; costs of, or changes in, laws and regulations and our failure to comply with new or existing laws or regulations, particularly with regard to taxes, safety and protection of the environment; the possibility that our hedging activities may result in losses or may have a negative impact on our financial results; general economic, market and business conditions; as well as other risk factors discussed from time to time in our each of our documents and reports filed with the SEC. Readers are cautioned not to place undue reliance on any forward-looking statements contained in this press release, which reflect management s opinions only as of the date hereof. Except as required by law, we undertake no obligation to revise or publicly release the results of any revision to any forward-looking statements. We use our Investor Relations website and social media outlets as channels of distribution of material company information. Such information is routinely posted and accessible on our Investor Relations website at ir.semgroupcorp.com. We are present on Twitter and LinkedIn: SemGroup Twitter and LinkedIn 3

Transformed Portfolio Provides Strategic Platform 2016-2018 Simplify Transform Rolled up Rose Rock Midstream MLP Sold non-core assets Acquired Gulf Coast platform Announced Canadian growth projects Deployed strategies to optimize existing assets Improved quality of cash flows Focused efforts to strengthen balance sheet Completed 2019 & Beyond Execute Strengthen Deliver Complete key projects Successfully renew contracts Focus on cost savings Continue deleveraging efforts Capital efficient growth around existing platforms Focus on project returns Unlock synergies in Canada and connect MidCon to Gulf Coast In Focus 4

2019 Guidance Highlights Adjusted EBITDA Guidance Cash Available for Dividend Guidance 2017-2019 CAGR of ~16% $394 $420 - $465 Guidance Range $178 $210 $155 - $200 Guidance Range ($USD in millions) $328 ($USD in millions) 2017 2018 2019E Capital Expenditures Guidance 2017 2018 2019E Dividend Guidance (1) ($USD in millions) $492 $375 $307 $262 (2) Growth Capex ($ per share) $1.82 $1.89 $1.89 $45 2017 2018 2019E Maintenance 2017 2018 2019E 5 1) Reflects asset sales and JV transactions, see page 15 for additional detail 2) Reflects SemGroup's 51% interest in SemCAMS Midstream JV

1Q18 2Q18 3Q18 4Q18 2018 2017 ($USD in millions, except per share) Net Income (loss) ($33.0) ($2.7) $8.4 $3.0 ($24.3) ($17.2) Adjusted EBITDA 93.4 99.0 96.4 105.4 394.2 328.3 Cash Available for Dividends 51.3 50.6 50.8 56.9 209.6 177.5 Common Dividend declared per share $0.4725 $0.4725 $0.4725 $0.4725 $1.89 $1.82 Dividend Coverage Ratio 1.4x 1.4x 1.4x 1.5x 1.4x 1.3x Consolidated Leverage Ratio 4.1x 5.6x 5.9x 5.3x 5.3x 5.1x Key Highlights Net Income down quarter over quarter reflecting higher income tax expense and foreign currency loss Adjusted EBITDA up 9% quarter over quarter due to higher crude transportation and HFOTCO terminalling revenues, offset by non-cash lower of cost or net realizable value inventory charge expected to reverse 1Q 2019 Declared quarterly common stock dividend of $0.4725 per share resulting in 1.5x coverage Full-year 2018 dividend of $1.89 and dividend coverage of 1.4x Elected non-cash, payment-in-kind (PIK) preferred stock dividend 6 Non-GAAP Financial Data Reconciliations are included in the Appendix to this presentation

2018 Segment Profit Results 1Q18 2Q18 3Q18 4Q18 2018 2017 ($USD in millions) U.S. Liquids (1) $68.1 $80.4 $75.5 $85.5 $309.4 $229.2 Crude Transportation (2) $34.3 $37.9 $38.1 $39.8 $150.1 $133.5 Crude Facilities (2) $9.3 $9.7 $8.2 $8.3 $35.5 $42.0 Crude Supply & Logistics (2) ($6.6) ($2.0) ($7.0) ($2.2) ($17.8) ($7.8) HFOTCO (2) $31.0 $34.8 $36.2 $39.6 $141.6 $61.5 U.S. Gas (1) $14.3 $15.4 $19.8 $17.6 $67.1 $67.8 SemGas (2) $14.3 $15.4 $19.8 $17.6 $67.1 $67.8 Canada (1) $22.1 $21.4 $20.5 $17.3 $81.3 $76.3 SemCAMS (2) $22.1 $21.4 $20.5 $17.3 $81.3 $76.3 Corporate and other $11.0 ($0.1) ($0.9) ($0.2) $9.8 $33.2 Total Segment Profit $115.4 $117.1 $114.9 $120.2 $467.5 $406.5 Fourth Quarter vs Third Quarter 2018 U.S. Liquids Improved marketing margins, offset by a non-cash $5.2 million lower of cost or net realizable value inventory charge expected to reverse 1Q 2019 Higher White Cliffs volumes as producers build shipper history ahead of one line converting to NGL Full quarter of new crude storage tanks at HFOTCO U.S. Gas: Decreased due to lower volumes and NGL prices Canada: Decreased due to timing of operating expense recoveries 7 1) Represents new segmentation 2) Represents prior segmentation, prospectively only new segments will be reported

2019 Financial Guidance 2018-2019E Adjusted EBITDA Bridge $394 Lower WCPL & U.S. Gas Divested Assets (1) Full Year HFOTCO Crude Terminalling Revenues Improved Marketing Margins Meritage Acquisition & New Wapiti Plant $420-465 Guidance Range ($USD in millions) 2019 Financial Guidance (2) Low-High U.S. Liquids $320 - $350 U.S. Gas $55 - $65 Canada (100% basis) $125 - $135 Consolidated Segment Profit $500 - $550 Adjusted G&A (3) $80 - $85 Consolidated Adjusted EBITDA $420 - $465 Cash Available for Dividend (4) $155 - $200 2018 2019E Transformed Portfolio Driving 2019 Growth and Beyond 8 1) Divested assets include SemMaterials Mexico and SemLogistics 2) 2019 guidance includes Meritage earnings beginning March 1, 2019 3) Adjusted for non-cash and non-reoccurring items, such as non-cash equity compensation and M&A one-time transaction costs 4) No material U.S. cash income taxes; expect approximately $8 million cash taxes related to Canadian intercompany debt forgiveness

2019 Capital Expenditure Guidance Total Capex Guidance $307 million (1) 2019 U.S. Capital Expenditure Guidance ($USD in millions) U.S. Liquids $135 U.S. Gas $15 Total Growth Capital $150 U.S. Gas $15 5% Maintenance Capital $40 Total U.S. Capital $190 2019 SemCAMS Midstream JV Capital Guidance ($USD in millions) Consolidated JV SemGroup 51% JV Interest Growth Capital $220 $112 Maintenance Capital $10 $5 Total Canada Capital $230 $117 U.S. Liquids $135 44% Maint $45 15% Canada $112 36% SemGroup's 2019 Capex Guidance $307 9 1) Reflects SemGroup's 51% interest in SemCAMS Midstream JV

2019 Operational Guidance & Key Growth Projects Key Growth Projects Expected Completion Estimated 2019 Capex Total Spend (1) EBITDA Multiple (2) U.S. Liquids White Cliffs NGL Pipeline Conversion (3) 1Q 2020 $27 $34 < 4x HFOTCO Moore Road Pipeline 4Q 2019 $62 $65 ~4x-8x Canada: SemCAMS Midstream JV Wapiti Plant (4) In service Jan 2019 $46 $250 ~7x Patterson Creek Plant Phase III 3Q 2019 $100 $210 (5) ~5-8x Smoke Lake Plant 4Q 2019 $30 $50 ~6x Pipestone Pipeline 4Q 2019 $24 $40 ~7x 2019 Operational Guidance Assumptions Guidance Capacity Notes U.S. Liquids HFOTCO Storage Utilization 97% - 99% 18.2 mm Cushing Storage Utilization 95% - 97% 7.6 mm Regulatory tank inspections begin in 2019 White Cliffs Pipeline Crude Volumes (mbbl/d) (6) 120-125 90 + Partial capacity out of service April 2019 (NGL conversion) U.S. Gas Gas Processing Volumes (mmcf/d) 320-360 595 Increased activity back half of 2019 Canada: SemCAMS Midstream JV K3, KA & West Fox Creek Plants (mmcf/d) 390-410 695 Legacy volumes Wapiti Plant (mmcf/d) (4) 100-110 200 Volumes ramp - Exit 4Q19 >150 mmcf/d Smoke Lake Plant (mmcf/d) 25 60 First volumes Nov 2019 at ~25 mmcf/d Patterson Creek Plant (mmcf/d) 140-150 195 Volumes ramp - Exit 4Q19 ~160 mmcf/d; capacity 395 mmcf/d 10 1) Total project spend reflects 100% basis for SemCAMS Midstream JV 2) Assumes developed multiple target 3) Represents SemGroup's 51% expected spend; total project spend of $60-66 million 4) Wapiti plant volumes ramp through 2020, estimated utilization of 75% by year-end 2019 and full capacity by mid-year 2020 5) Includes USD $110 million of 2018 capex spent prior to close 6) Includes 3rd party offload capacity agreement

2019 Strategic Goals and Priorities BALANCE prudent capital management with CAPTURING strategic growth opportunities Capture Growth Opportunities Expand SemCAMS Midstream JV Footprint Montney liquids takeaway via proposed Montney to Market (M2M) Pipeline Connect Mid-Con & Gulf Coast assets via proposed Gladiator Pipeline Maximize export opportunities at HFOTCO to meet growing demand Continue Deleveraging Efforts Capture EBITDA growth from organic projects Evaluate partner funding for new growth projects Consider additional JVs and asset sales Opportunistically seek other sources of cost-effective capital Complete Key Growth Projects Expand Canadian system connectivity and capacity Pipestone Pipeline, Patterson Creek Expansion, Smoke Lake Plant Conversion of White Cliffs pipe to NGL service Increase HFOTCO connectivity via Moore Road pipeline Commercialization & Asset Optimization Execute contract renewals across portfolio Integrate Meritage and SemCAMS assets Enhance HFOTCO pipeline connectivity 11

Appendix

SemCAMS Midstream Guidance and Reporting Contiguous Assets Strategically Positioned Ñ Ñ Ñ Ñ SemCAMS Midstream 2019 Guidance (1) ($USD) Segment Profit of $125 - $135 million Growth Capex of $220 million Maintenance Capex of $10 million Minimum cash taxes Ñ Maintain leverage ratio between 3.0x - 3.5x Ñ Ñ Ñ Ñ Ñ Impact to SemGroup Consolidated Reporting Adjusted EBITDA guidance reflects Meritage ownership from the close of the acquisition (March 2019 - forward) JV will be fully consolidated on SemGroup's financial statements KKR interest reflected as non-controlling interest on SemGroup's financial statements SemGroup consolidated leverage ratio will reflect 100% of the JV's debt and Adjusted EBITDA SemGroup bank leverage ratio will not include JV debt and will reflect the 51% cash distribution as EBITDA Ñ SemGroup CAFD will reflect 51% interest of the JV CAFD 13 1) Guidance reflects 100% SemCAMS Midstream JV

Joint Venture Reporting for Key Metrics SemGroup Controls and Fully Consolidates SemGroup Does Not Consolidate (Equity Method) Joint Ventures SemCAMS Midstream (51%) Maurepas Pipeline (51%) White Cliffs Pipeline (51%) Net Income Includes 100% of JV Net Income (consolidated throughout income statement line items) Includes SemGroup's ownership % of JV Net Income (included in earnings from equity investments) Net Income to Common Shareholders Adjusted EBITDA Includes SemGroup's ownership % of JV Net Income (excludes net income attributable to noncontrolling interests) Includes 100% of Adjusted EBITDA Includes SemGroup's ownership % of JV Net Income (included in earnings from equity investments) Includes SemGroup's ownership % of JV Net Income +DD&A Debt 100% of JV debt included, if any (fully consolidated on balance sheet) No JV Debt Maintenance Capital Includes 100% of consolidated GAAP financials Funded from JV operations or Equity Capital Contributions CAFD Includes SemGroup's ownership % of JV CAFD 14

Reporting of Cash Available for Dividend Cash Available for Dividend Description 2019 Guidance Low High Consolidated Adjusted EBITDA Consolidated Basis (100% SemCAMS Midstream JV & Maurepas) $420 $465 less: cash interest Consolidated Basis (100% SemCAMS Midstream JV) (159) (149) less: maintenance capital Consolidated Basis (100% SemCAMS Midstream JV & Maurepas) (50) (50) less: cash paid for income taxes Consolidated Basis (100% SemCAMS Midstream JV & Maurepas) (4) (4) less: corporate preferred distribution Corporate Pref (announced 1/16/2018, 10 quarter PIK option) less: noncontrolling interest 49% of SemCAMS Midstream JV & Maurepas CAFD (52) (62) add: other non-recurring items Ex: add back taxes on gain from sale of Mexico Cash Available for Dividend CAFD Total $155 $200 CAFD per share (CAFD Total / Shares Outstanding) $1.98 $2.55 Dividends Declared (Declared Dividend x Shares Outstanding) $148 $148 Dividend Coverage (CAFD Total / Dividends Declared) 1.1x 1.4x 15

SemCAMS Midstream Illustrative Capital Structure $ in millions Assets $CAD $USD SemCAMS Valuation (1) $1,237 $938 Meritage Valuation (1) (2) 646 490 Other Net Assets 7 5 Total Assets $1,890 $1,433 Capital Structure $CAD $USD Common Equity - SemGroup $599 $454 Common Equity - KKR 576 437 Preferred Equity - KKR 300 227 JV Term Loan 350 265 JV Revolver 65 49 Total Capital Structure $1,890 $1,433 Cash Back to SemGroup $CAD $USD SemCAMS Valuation $1,237 $938 less SemGroup Equity (599) (454) Cash Proceeds to SemGroup $638 $484 Common Equity Ownership $CAD % Common Equity - SemGroup $599 51% Common Equity - KKR 576 49% Total Common Equity $1,175 100% 16 Assumes CAD / USD closing date exchange rate of 0.7583 1) Subject to customary post closing adjustments 2) Includes CAD $152 million capital reimbursement through closing and estimated working capital adjustment

Portfolio Transformation Driving Secure Cash Flows Over 95% of Total LTM Gross Margin from Fee Based Cash Flows 11% 5% 2% 3% 89% 95% 98% 97% 49% 58% 38% 2016 2017 2018 2019E Fee Based POP/Marketing Take-or-Pay 17

Leverage and Liquidity Interest Rate 12/31/2018 ($USD in millions, unaudited) SemGroup (B2 / B+) Revolving Credit Facility - $1.0 billion due 2021 $120 Senior unsecured notes due 2022 5.625% 400 Senior unsecured notes due 2023 5.625% 350 Senior unsecured notes due 2025 6.375% 325 Senior unsecured notes due 2026 7.250% 300 Total SemGroup Debt $1,495 HFOTCO (Ba3 / BB-) Term Loan due 2025 5.280% 597 Hurricane Ike Bonds due 2050 3.399% 225 Total HFOTCO Debt $822 SemGroup Bank Covenant Net Leverage Ratio (1) 4.2x Consolidated Net Leverage Ratio (2) 5.3x Consolidated Available Liquidity (3) $943 18 1) SemGroup's bank covenant net leverage ratio calculated per the senior secured credit facility definitions, which includes a pro-rata portion of projected future annual EBITDA from material projects 2) Calculated as consolidated net debt to LTM consolidated leverage EBITDA. See additional information on slide 28 3) Available liquidity is reduced for outstanding letters of credit covenant

Operational Summary Key Asset Volumes 1Q18 2Q18 3Q18 4Q18 FY 2018 White Cliffs Pipeline Volumes (mbbl/d) 107 135 112 144 125 Cushing Terminal Utilization 98% 97% 94% 98% 97% HFOTCO Terminal Utilization 97% 97% 96% 96% 97% 305 367 395 369 359 441 382 434 430 422 U.S. Liquids U.S. Gas (1) Total Average Processing Volumes (mmcf/d) Canada (2) Total Average Processing Volumes (mmcf/d) 19 1) SemGas volumes include total processed volumes - Oklahoma and Texas plants 2) SemCAMS volumes include total processed volumes - K3, KA and West Fox Creek facilities

Consolidated Balance Sheets (in thousands, unaudited, condensed) December 31, 2018 December 31, 2017 ASSETS Current assets $715,825 $902,899 Property, plant and equipment, net 3,457,326 3,315,131 Goodwill and other intangible assets 622,340 655,945 Equity method investments 274,009 285,281 Other noncurrent assets, net 140,807 132,600 Noncurrent assets held for sale 84,961 Total assets $5,210,307 $5,376,817 LIABILITIES, PREFERRED STOCK AND OWNERS' EQUITY Current liabilities: Current portion of long-term debt $6,000 $5,525 Other current liabilities 631,157 761,036 Total current liabilities 637,157 766,561 Long-term debt, excluding current portion 2,278,834 2,853,095 Other noncurrent liabilities 94,337 85,080 Noncurrent liabilities held for sale 13,716 Total liabilities 3,010,328 3,718,452 Preferred stock 359,658 Owners' equity 1,840,321 1,658,365 Total liabilities, preferred stock and owners' equity $5,210,307 $5,376,817 20

Consolidated Statements of Operations and Comprehensive Income (Loss) (in thousands, except per share amounts, unaudited, condensed) 2018 2017 Q1 Q2 Q3 Q4 FY2018 Q1 Q2 Q3 Q4 FY2017 Revenues $661,609 $595,794 $633,996 $611,863 $2,503,262 $456,100 $473,089 $545,922 $606,806 $2,081,917 Expenses: Costs of products sold, exclusive of depreciation and amortization shown below 496,132 412,089 468,871 446,003 1,823,095 348,998 340,107 398,252 427,534 1,514,891 Operating 69,791 90,245 64,835 59,898 284,769 52,083 73,346 62,666 66,669 254,764 General and administrative 26,477 22,886 21,904 20,301 91,568 21,712 26,819 38,389 26,859 113,779 Depreciation and amortization 50,536 51,755 53,598 53,365 209,254 24,599 25,602 50,135 58,085 158,421 Loss (gain) on disposal or impairment, net (3,566) 1,824 (383) (1,438) (3,563) 2,410 (234) 41,625 (30,468) 13,333 Total expenses 639,370 578,799 608,825 578,129 2,405,123 449,802 465,640 591,067 548,679 2,055,188 Earnings from equity method investments 12,614 14,351 14,528 16,179 57,672 17,091 17,753 17,367 15,120 67,331 Operating income (loss) 34,853 31,346 39,699 49,913 155,811 23,389 25,202 (27,778) 73,247 94,060 Other expenses, net 44,805 37,685 33,935 40,410 156,835 33,571 11,966 28,574 39,487 113,598 Income (loss) from continuing operations before income taxes (9,952) (6,339) 5,764 9,503 (1,024) (10,182) 13,236 (56,352) 33,760 (19,538) Income tax expense (benefit) 23,083 (3,613) (2,697) 6,531 23,304 95 3,625 (37,249) 31,141 (2,388) Net income (loss) (33,035) (2,726) 8,461 2,972 (24,328) (10,277) 9,611 (19,103) 2,619 (17,150) Less: net income attributable to noncontrolling interest 2,421 2,421 Net income (loss) attributable to SemGroup (33,035) (2,726) 8,461 551 (26,749) (10,277) 9,611 (19,103) 2,619 (17,150) Less: cumulative preferred stock dividends 4,832 6,211 6,317 6,430 23,790 Net income (loss) attributable to common shareholders ($37,867) ($8,937) $2,144 ($5,879) ($50,539) ($10,277) $9,611 ($19,103) $2,619 ($17,150) Net income (loss) ($33,035) ($2,726) $8,461 $2,972 ($24,328) ($10,277) $9,611 ($19,103) $2,619 ($17,150) Other comprehensive income (loss), net of income taxes 18,171 6,180 3,352 (25,149) 2,554 6,033 8,952 9,230 (4,102) 20,113 Comprehensive income (loss) ($14,864) $3,454 $11,813 ($22,177) ($21,774) ($4,244) $18,563 ($9,873) ($1,483) $2,963 Net income (loss) per common share: Basic ($0.48) ($0.11) $0.03 ($0.08) ($0.65) ($0.16) $0.15 ($0.25) $0.03 ($0.24) Diluted ($0.48) ($0.11) $0.03 ($0.08) ($0.65) ($0.16) $0.15 ($0.25) $0.03 ($0.24) Weighted average shares (thousands): Basic 78,198 78,319 78,353 78,378 78,313 65,692 65,749 75,974 78,189 71,418 Diluted 78,198 78,319 78,977 78,378 78,313 65,692 66,277 75,974 78,749 71,418 21

Non-GAAP Adjusted EBITDA Calculation (in thousands, unaudited) 2018 2017 Reconciliation of net income to Adjusted EBITDA: Q1 Q2 Q3 Q4 FY2018 Q1 Q2 Q3 Q4 FY2017 Net income (loss) ($33,035) ($2,726) $8,461 $2,972 ($24,328) ($10,277) $9,611 ($19,103) $2,619 ($17,150) Add: Interest expense 42,461 35,904 35,318 36,031 149,714 13,867 13,477 32,711 42,954 103,009 Add: Income tax expense (benefit) 23,083 (3,613) (2,697) 6,531 23,304 95 3,625 (37,249) 31,141 (2,388) Add: Depreciation and amortization expense 50,536 51,755 53,598 53,365 209,254 24,599 25,602 50,135 58,085 158,421 EBITDA 83,045 81,320 94,680 98,899 357,944 28,284 52,315 26,494 134,799 241,892 Selected Non-Cash Items and Other Items Impacting Comparability 10,326 17,690 1,771 6,453 36,240 32,383 13,095 64,239 (23,306) 86,411 Adjusted EBITDA $93,371 $99,010 $96,451 $105,352 $394,184 $60,667 $65,410 $90,733 $111,493 $328,303 Selected Non-Cash Items and Other Items Impacting Comparability Loss (gain) on disposal or impairment, net ($3,566) $1,824 ($383) ($1,438) ($3,563) $2,410 ($234) $41,625 ($30,468) $13,333 Foreign currency transaction loss (gain) 3,294 2,314 (983) 4,876 9,501 (1,011) (747) (2,951) (4,709) Adjustments to reflect equity earnings on an EBITDA basis 4,883 4,886 4,926 4,837 19,532 6,709 6,692 6,678 6,811 26,890 M&A transaction related costs 1,156 648 290 1,058 3,152 5,453 14,886 1,649 21,988 Pension plan curtailment loss (gain) (3,097) 89 (3,008) Employee severance and relocation expense 137 211 43 758 1,149 558 312 104 720 1,694 Unrealized loss (gain) on derivative activities 2,226 4,409 (4,860) (6,828) (5,053) 27 (928) 1,833 (892) 40 Non-cash equity compensation 2,196 3,398 2,738 3,190 11,522 2,757 2,803 2,957 1,736 10,253 Loss on early extinguishment of debt 19,922 8 19,930 Selected Non-Cash items and Other Items Impacting Comparability $10,326 $17,690 $1,771 $6,453 $36,240 $32,383 $13,095 $64,239 ($23,306) $86,411 22

Non-GAAP Adjusted EBITDA Calculation (in thousands, unaudited) 2016 Reconciliation of net income to Adjusted EBITDA: Q1 Q2 Q3 Q4 FY2016 Net income (loss) ($4,893) $10,787 ($4,632) $12,000 $13,262 Add: Interest expense 17,577 18,011 18,517 8,545 62,650 Add: Income tax expense (benefit) (21,407) 4,658 11,898 16,119 11,268 Add: Depreciation and amortization expense 24,051 25,055 24,922 24,776 98,804 EBITDA 15,328 58,511 50,705 61,440 185,984 Selected Non-Cash Items and Other Items Impacting Comparability 62,340 9,121 20,585 4,765 96,811 Adjusted EBITDA $77,668 $67,632 $71,290 $66,205 $282,795 Selected Non-Cash Items and Other Items Impacting Comparability Loss on disposal or impairment, net $13,307 $1,685 $1,018 $38 $16,048 Loss (income) from discontinued operations, net of income taxes 2 2 (3) 1 Foreign currency transaction loss 1,469 1,543 659 1,088 4,759 Adjustments to reflect equity earnings on an EBITDA basis 9,221 7,138 7,321 5,077 28,757 Remove loss (gain) on sale or impairment of NGL units 39,764 (9,120) 30,644 M&A transaction related costs 3,269 3,269 Employee severance and relocation expense 259 836 534 499 2,128 Unrealized loss (gain) on derivative activities (4,548) 4,477 6,167 (5,107) 989 Non-cash equity compensation 2,866 2,560 1,620 3,170 10,216 Selected Non-Cash items and Other Items Impacting Comparability $62,340 $9,121 $20,585 $4,765 $96,811 23

Segment Profit and Adjusted EBITDA (in thousands, unaudited) 2018 2017 Segment Profit: Q1 Q2 Q3 Q4 FY2018 Q1 Q2 Q3 Q4 FY2017 U.S. Liquids $68,056 $80,393 $75,500 $85,474 $309,423 $35,387 $36,336 $70,202 $87,283 $229,208 U.S. Gas 14,277 15,437 19,754 17,602 67,070 18,227 19,483 15,555 14,540 67,805 Canada 22,113 21,448 20,543 17,226 81,330 16,865 19,038 16,704 23,667 76,274 Corporate and other 10,963 (172) (913) (152) 9,726 8,367 8,296 8,421 8,152 33,236 Total Segment Profit 115,409 117,106 114,884 120,150 467,549 78,846 83,153 110,882 133,642 406,523 Less: General and administrative expense 26,477 22,886 21,904 20,301 91,568 21,712 26,819 38,389 26,859 113,779 Other income (950) (533) (400) (497) (2,380) (218) (508) (3,390) (516) (4,632) Pension curtailment gain (loss) 3,097 (89) 3,008 Plus: M&A related costs 1,156 648 290 1,058 3,152 5,453 14,886 1,649 21,988 Employee severance and relocation 137 211 43 758 1,149 558 312 104 720 1,694 Non-cash equity compensation 2,196 3,398 2,738 3,190 11,522 2,757 2,803 2,957 1,736 10,253 Consolidated Adjusted EBITDA $93,371 $99,010 $96,451 $105,352 $394,184 $60,667 $65,410 $90,733 $111,493 $328,303 24

Segment Profit Under Prior Segmentation (in thousands, unaudited) 2018 2017 Segment Profit: Q1 Q2 Q3 Q4 FY2018 Q1 Q2 Q3 Q4 FY2017 Crude Transportation $34,310 $37,865 $38,135 $39,794 $150,104 $28,251 $29,028 $34,585 $41,641 $133,505 Crude Facilities 9,341 9,683 8,209 8,244 35,477 9,564 9,481 8,806 14,116 41,967 Crude Supply and Logistics (6,583) (1,959) (7,005) (2,252) (17,799) (2,428) (2,173) (1,693) (1,506) (7,800) HFOTCO 30,988 34,804 36,161 39,688 141,641 28,504 33,032 61,536 SemGas 14,277 15,437 19,754 17,602 67,070 18,227 19,483 15,555 14,540 67,805 SemCAMS 22,113 21,448 20,543 17,226 81,330 16,865 19,038 16,704 23,667 76,274 Corporate and other 10,963 (172) (913) (152) 9,726 8,367 8,296 8,421 8,152 33,236 Total Segment Profit 115,409 117,106 114,884 120,150 467,549 78,846 83,153 110,882 133,642 406,523 Less: General and administrative expense 26,477 22,886 21,904 20,301 91,568 21,712 26,819 38,389 26,859 113,779 Other income (950) (533) (400) (497) (2,380) (218) (508) (3,390) (516) (4,632) Pension curtailment gain (loss) 3,097 (89) 3,008 Plus: M&A related costs 1,156 648 290 1,058 3,152 5,453 14,886 1,649 21,988 Employee severance and relocation 137 211 43 758 1,149 558 312 104 720 1,694 Non-cash equity compensation 2,196 3,398 2,738 3,190 11,522 2,757 2,803 2,957 1,736 10,253 Consolidated Adjusted EBITDA $93,371 $99,010 $96,451 $105,352 $394,184 $60,667 $65,410 $90,733 $111,493 $328,303 25

Reconciliation of Operating Income to Total Segment Profit (in thousands, unaudited) 2018 2017 Q1 Q2 Q3 Q4 FY2018 Q1 Q2 Q3 Q4 FY2017 Operating income (loss) $34,853 $31,346 $39,699 $49,913 $155,811 $23,389 $25,202 ($27,778) $73,247 $94,060 Plus: Adjustments to reflect equity earnings on an EBITDA basis 4,883 4,886 4,926 4,837 19,532 6,709 6,692 6,678 6,811 26,890 Unrealized loss (gain) on derivatives 2,226 4,409 (4,860) (6,828) (5,053) 27 (928) 1,833 (892) 40 General and administrative expense 26,477 22,886 21,904 20,301 91,568 21,712 26,819 38,389 26,859 113,779 Depreciation and amortization 50,536 51,755 53,598 53,365 209,254 24,599 25,602 50,135 58,085 158,421 Loss (gain) on disposal or impairment, net (3,566) 1,824 (383) (1,438) (3,563) 2,410 (234) 41,625 (30,468) 13,333 Total Segment Profit $115,409 $117,106 $114,884 $120,150 $467,549 $78,846 $83,153 $110,882 $133,642 $406,523 26

Cash Available for Dividends (in thousands, unaudited) 2018 2017 Q1 Q2 Q3 Q4 FY2018 Q1 Q2 Q3 Q4 FY2017 Adjusted EBITDA $93,371 $99,010 $96,451 $105,352 $394,184 $60,667 $65,410 $90,733 $111,493 $328,303 Less: Cash interest expense 32,530 34,870 36,377 35,372 139,149 17,976 18,396 29,621 35,203 101,196 Less: Maintenance capital 7,729 11,550 8,635 8,664 36,578 8,272 11,850 12,693 9,597 42,412 Less: Cash paid for income taxes 1,800 12,900 600 1,500 16,800 1,155 1,721 196 4,088 7,160 Less: Distributions to noncontrolling interests (1) 2,932 2,932 Less: Preferred stock dividends (2) Selected items impacting comparability: Add back: Mexico disposal cash taxes 10,955 10,955 Cash available for dividends $51,312 $50,645 $50,839 $56,884 $209,680 $33,264 $33,443 $48,223 $62,605 $177,535 Dividends declared $37,004 $37,022 $37,022 $37,034 $148,082 $29,584 $35,171 $35,184 $36,961 $136,900 Dividend coverage ratio 1.4x 1.4x 1.4x 1.5x 1.4x 1.1x 1.0x 1.4x 1.7x 1.3x 27 1) Distributions to noncontrolling interest represents Alinda s 49% interest in Maurepas Pipeline and will also include KKR's 49% interest in SemCAMS Midstream joint venture 2) To date preferred stock dividends have been paid-in-kind

Reconciliation of Adjusted EBITDA to Pro Forma Consolidated Leverage EBITDA (in millions, unaudited) Adjusted EBITDA 4Q18 $105.4 3Q18 96.4 2Q18 99.0 1Q18 93.4 LTM Adjusted EBITDA 394.2 Adjustments 22.7 LTM Consolidated Leverage EBITDA $416.9 Acquisition / divestitures adjustment (1) (28.7) Material projects adjustment (2) 35.2 Tax adjustment 13.2 Miscellaneous adjustment 3.0 Total Adjustments (3) $22.7 28 1) Includes proforma LTM results for SemMexico, SemLogistics and Maurepas 49% minority interest divestitures 2) Pro-rata portion of projected future annual EBITDA from material projects 3) Consistent with adjustments permitted under SemGroup's senior secured credit facility