Alta Corp Capital ConferenceInvestor Presentation

September 2018

Non-GAAP Financial Measures

2

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 non-recurring, 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.

Forward-Looking Information

3

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 failure to realize the anticipated benefits of our acquisition of 100 percent of the equity interests in Buffalo Parent Gulf Coast Terminals LLC, the parent company of Buffalo Gulf Coast Terminals LLC and HFOTCO LLC, doing business as Houston Fuel Oil Terminal Company (“HFOTCO”); 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 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

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MID-CONTINENT

• 1,700 miles crude pipelines• 8.8 million barrels crude oil storage

capacity• 200 crude oil trucks/trailers• 1,000 miles gas gathering pipelines• 4 gas processing plants (600

mmcf/d total)• 680,000 dedicated gas gathering

acres from key producers

• 330 acres on Houston Ship Channel• 18.2 million barrels product storage• Connectivity to Gulf Coast refining complex• Significant inbound pipeline connectivity• Deepwater marine access• Rail and truck loading and unloading• Maurepas Pipeline serving refineries

Strategic position in North America’s largest energy complexGULF COAST t

CANADAUnique platform in liquids-rich Montney and Duvernay

• 4 natural gas processing plants• 600 miles natural gas gathering pipelines• 200 mmcf/d Wapiti Gas Plant under construction• Smoke Lake Plant under construction• 1 bcf/d combined operating capacity(1) with significant sulfur recovery

DJ Basin, STACK, Cushing and Northeast OK

SemGroup Operations Across Midstream Value Chain

1) Pro forma plants under construction

5

Over 70% of SemGroup's pro forma revenue is derived from investment grade counterparties

97% of total LTM gross margin fromfee-based cash flows

SemGroup Strengths

1) LTM June 30, 2018, pro forma for full-year HFOTCO acquisition and Maurepas Pipeline2) LTM June 30, 2018; excludes divested assets, Glass Mountain Pipeline, SemLogistics and SemMaterials Mexico

Counterparty Strength(2)Stable Cash Flows

SemGroup derives a significant portion of cash flows from fixed-fee, contracted arrangements from credit-worthy counterparties

6

SemGroup Financial Growth Aligned with Stable Fee-Based Assets

NOTE: Non-GAAP Financial Data Reconciliations are included in the Appendix to this presentation

1) Take-or-pay % of gross margin: LTM June 30, 2018, pro forma for full-year HFOTCO acquisition and Maurepas Pipeline

7

SemGroup Strategic Focus:▶ Developing unique US Gulf Coast position to leverage export opportunities▶ Capturing significant growth potential in Montney & Duvernay plays in Canada▶ Leveraging Mid-Con footprint to capture growing crude and NGL takeaway needs▶ Driving capital funding initiatives to reduce balance sheet leverage

Transforming Portfolio

Executing Opportunities

Delivering Shareholder

Value

7

Driving Shareholder Value

Clear Path to Long-Term Growth

SemCAMSOverview

8

9

Unique Footprint Difficult to Replicate

▶ Strategic location for processing sour gas originating from the Wapiti, Montney and Duvernay plays

• Total combined operating capacity of ~1 bcf/d(1) – licensed capacity of 1.5 bcf/d

• Operator and majority owner in four sour & sweet gas plants Kaybob South #3 (K3) Kaybob Amagamated (KA) West Fox Creek West Whitecourt (WWC)

• Announced plant projects Wapiti (under construction) Smoke Lake (under construction) Pipestone (proposed)

• 600 miles of sour and sweet gas gathering pipelines• Multiple takeaway options provide flexibility to producers

TransCanada (Gas) Alliance (Gas) Pembina (Liquids) Rail and truck loading capabilities

SemCAMS owns and operates a vast network of essential midstream infrastructure in Alberta, servicing the prolific Montney and Duvernay plays

1) Pro forma plants under construction

SemCAMS Midstream Platform

10

Stable Cash Flows Supported by Strong

Counterparties

▶ 100% fee-based contracts with no direct commodity price exposure ▶ Take-or-pay contracts account for an estimated 40% of 2018 contracted revenue ▶ Turnaround, opex, and maintenance expenses flow through to producers

Visible Growth Opportunities

▶ Approximately USD $200 million forecasted growth capex spend in 2018, supported by long-term take-or-pay contracts at attractive multiples

▶ Identified future plant and pipeline growth opportunities

Unique Asset Footprint Located in

Prolific Plays

▶ Largest sour gas processor with dominate footprint in the core of the Monteney and Duverney plays with 1 bcf/d of combined operating sour gas processing capacity

▶ Capable of processing sour and sweet gas as well as condensate and liquids handling ▶ Wapiti Pipeline provides Montney producers with Acid Gas Transfer (AGT) to sulfur-

recovery plants at K3, capable of handling up to 30% H2S▶ 98% plant reliability over the past 18 years▶ Unit train capabilities at KA and K3 for liquids and sulfur▶ Multiple takeaway options provide flexibility to producers

440 426 381 426 407 411

2013 2014 2015 2016 2017 2018 YTD

$34.1$45.9

$37.2 $40.1

$59.9

2013 2014 2015 2016 2017

99% 97% 99% 100%92%

97% 95%100% 100%

96%100% 99%

0%10%20%30%40%50%60%70%80%90%

100%

2007

T

2008

2009

T

2010

2011

2012

T

2013

T

2014

2015

2016

2017

T

2018

T YT

D

SemCAMS Performance

1) Includes KA and K3 plants; excludes planned outages (plant turnarounds)2) SemCAMS volumes include total processed volumes - K3, KA and West Fox Creek facilities3) Scheduled plant turnaround at KA4) Scheduled plant turnaround at K3Note: Year to date as of June 30, 2018 and Non-GAAP Financial Data Reconciliations are included in the Appendix to this presentation

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Plant Reliability(1) Average Throughput Volume(2) (mmcf/d)

(4)

Adjusted EBITDA (USD$MM)Customers

(3)

T = Turnaround Years(3)

Historical reliability of >98%, excluding planned outages

The Montney and Duvernay Plays

12

Canadian Condensate Market Overview

Source: RBC Capital Markets, Government Data

13

“Western Canada willlikely remain shortcondensate for theforeseeable futuresupporting itspremium vs. Edmonton condensate and rough parity withWTI (C$)” - RBC

Oil sands diluent demand, combined with short fall in local condensate supply will continue to drive production growth

“Condensate demandin western Canada isexpected to outstripdomestic supply, withimports bridging the gap and rail playinga bigger role.” - RBC

14

Proposed Pipestone Plant

Wapiti Project

KA Plant & Smoke Lake Project

West Fox Creek PlantWest Whitecourt Plant

K3 Plant

Wapiti/Pipestone

Kaybob

Wapiti Pipeline to KA and K3

Dominate Footprint in Heart of Montney & Duvernay▶ Liquids rich; high percentages of condensate & NGLs ▶ Condensate & NGL’s command higher prices▶ Horizontal drilling has unlocked potential by reducing

drilling cost ▶ Existing assets ideally situated to take advantage of

aggressive Montney and Duvernay growth

0.0

2.0

4.0

6.0

8.0

2010 2011 2012 2013 2014 2015 2016 2017 2018

Duvernay Montney AB Montney BC

Fundamentals Underpinned by Economic Upstream Resource

Exposure to growing Montney & Duvernay production

SemCAMS Growth Area Production Bcf/d

Source: Scotia Bank and GeoScout

▶ As Montney production continues to grow, there is a deep inventory of potential new build infrastructure projects across the fairway

▶ SemCAMS’ liquids processing and sour plant experience are clear competitive advantages as Montney operators continue to be focused on liquids-rich opportunities

▶ Producers have increasingly encountered sour gas in new emerging areas

Montney, Significant Development Potential

15

Cenovus Pipestone Montney acreage recently acquired by NuVista

Wapiti Pipestone Montney Mineral Rights

2017–18 Wapiti/Montney Drilling Activity by Producer

96

32 30 2211 17 18 11 12 8 8 8 10 5 7 5 5

15

61

19 1720

23 7 310 3 6 4 4 1

5 1

16

0

20

40

60

80

100

120

140

160

180

2017 2018 YTD

NuVista Energy is Top 3 In Montney Drilling Activity Since

2017 in the Wapiti Pipestone Area

Source: Company disclosures and GeoScout

▶ SemCAMS’ existing area infrastructure, technical expertise, and operational track record are clear competitive advantages as operators look for long-term gathering and processing solutions

▶ Operators are increasingly encountering sour production in the Duvernay and estimate that as much as 25% of Duvernay could be sour

▶ Major Duvernay producers in the Kaybob area continue to flow sour production to our KA facility

▶ Smoke Lake plant under construction located north of KA to process incremental sour gas production

Footprint in the Core of the Duvernay

16 26

Duvernay Mineral Rights

2017–18 Duvernay Drilling Activity by Producer

32

16 156

44

8

15

17 17

10

22

15 1

0

10

20

30

40

50

60

70

Chevron Encana Murphy Paramount Shell XTO Energy Other

2017 2018 YTD

Source: Company disclosures and GeoScout.

Announced Growth Projects

17

Wapiti Sour Gas Processing Plant – UnderwaySemCAMS Ideally Situated to Take Advantage of Aggressive Montney Growth

18

▶ SemCAMS is building a 100% owned 200 mmcf/d sour gas processing plant in the Wapiti area of Alberta

▶ Leverages existing assets in the Kaybob area for a unique sour gas handling solution• Acid Gas Transfer - utilize existing Wapiti pipeline

system for transportation of acid gas to K3 plant for processing

▶ Producer development activity driven by condensate demand• Condensate handling capacity of 20,000 bbl/d

▶ Investment is backstopped by NuVista

• 120 mmcf/d, 15-year contract (80% take-or-pay)▶ Anticipate contracting the remaining capacity by

year-end 2018▶ Total project cost of ~USD $225 - $250 million▶ 6x EBITDA multiple▶ Plant completion early 2019

Photo: Site construction progress as of June, 2018

Proposed Pipestone Gas Processing Plant

19

▶ Filed permit to construct new 280 mmcf/d gas processing plant

▶ In discussion with multiple producers in Pipestone area to gauge interest

▶ Condensate handling capacity of 20,000 bbls/d

▶ Acid gas processed in Pipestone area will be transferred to K3 via existing SemCAMS infrastructure

A

B

CD

E

F

G

H

I

KL

J

Pipestone Project

Wapiti Project

Wapiti Pipeline to KA and K3

AlbertaBritish

Columbia

20

▶ Constructing 60 mmcf/d sour & sweet processing facility located in close proximity to KA plant

▶ Project cost ~USD $50 million

▶ 6x EBITDA multiple

▶ Plant completion ~ 4Q 2019

▶ Supported by 15-year contract with Murphy Oil and Athabasca Oil

▶ ~90% of capacity contracted and underpinned by take-or-pay contracts

▶ Connectivity to KA for liquids and excess raw gas providing producers with a flexible and reliable processing solution

A

C

D

E

F

G

H

I

KL

J

Kaybob Amalgamated

Kaybob South #3

Wapiti Pipeline

AlbertaBritish

Columbia

B

Smoke Lake Project

WindfallWest Fox Creek

Smoke Lake Plant Enhances Position in Duvernay

▶ Joint Open Season announced August 2018 with Plains Midstream Canada▶ Proposed project includes utilizing existing and new pipelines to carry crude, condensate and

NGLs from Pipestone area delivering to Edmonton and Fort Saskatchewan▶ Initial capacity 100,000 bbl/d; capacity can be increased to 200,000 bbl/d▶ Proposed completion ~4Q 2020

Montney to Market Pipeline (M2M)

21

22

Experienced and reliable

operator

Stable cash flows supported by credit-worthy

customers

Irreplicable sour gas processing

andacid gas transfer

solution

Takeaway optionality

via pipeline, truck & rail

SemCAMS Competitive Advantages

Facility interconnections

provideoperational flexibility &

optimization

Asset footprint in prolific

Montney and Duvernay

plays

Appendix

23

SemCAMS Management

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SemCAMS Background

David (Dave) GosseVP & General Manager

Vice President and General Manager for SemCAMS

Responsible for establishing SemCAMS’ goals, strategic direction, workforce safety and accountability

Started with SemCAMS in 2011 as the Vice President of Operations; responsibility included plant operations,engineering, health, environment and safety, asset integrity and supply chain management

MBA from Athabasca University and is a professional engineer with more than 25 years of experience in theenergy industry

Christopher DutcherVice President,

Business Development

Works with the SemGroup business development teams and the SemCAMS Management team to identifybusiness development opportunities including joint venture initiatives

Joined SemCAMS in March of 2015 and has over 25 years of progressive development experience with KeyeraCorporation and Petrofund Energy Trust

Professional engineer and has Bachelor of Science (Honors) in Mechanical Engineering and an MBA from Queen’sUniversity

Leanne CampbellVice President, Legal

Accountable for all legal requirements of SemCAMS, relative to its Canadian operations

Also oversees joint venture administration and data management teams

Joined SemCAMS in 2013 and has over 25 years of advisory and counsel experience, including a diversebackground in commercial negotiations, compliance and regulatory, corporate reputation, and legal riskmanagement for companies such as Cenovus and Encana as well as in private practice

Bachelor of Arts from the University of Calgary, a Bachelor of Law from the University of Alberta

Heather JonesDirector, Finance

Accountable for the Finance requirements of SemCAMS

Joined SemCAMS in 2010 with over 20 years of experience with Murphy Oil where she served in capacities ofInternal Audit, Assistant Controller and Controller

Bachelor of Commerce from the University of Calgary and is a designated Chartered Accountant with the Instituteof Chartered Accountants of Alberta, which she obtained while working with KPMG LLP

Sweet Vs. Sour Gas Processing

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Sweet Gas Processing Sour Gas Processing

Inlet Separation & Compression - Free Liquid and Solid Removal Material Selection can vary Material Selection can vary

Emergency Pressure Relief Can be to atmosphere Must be direct to flare

Routine Venting of Gas Over 0.018 mmcf/d to flare All venting to flare

H2S Removal None Required Requires Process – Amine is typical

CO2 Removal Maybe Required – Amine is typical Maybe Required – Amine is typical

H2S/CO2 (Acid Gas) HandlingIf CO2 is removed it needs to be vented or disposed (typically via underground injection)

Acid Gas needs to be handled through:CO2 – Vented or Underground InjectionH2S – Conversion to Sulfur (SRU), Underground Injection (AGI) or Flared (typically in low volumes of < 1 tonne/day)

Water Dewpoint Conditioning Maybe Required – Same as Sour -Glycol or Mole Sieve are typical

Maybe Required – Same as Sweet -Glycol or Mole Sieve are typical

Hydrocarbon Dewpoint Conditioning

Maybe Required – Same as Sour -Refrigeration, Turbo Expander, Joule Thompson are typical

Maybe Required – Same as Sweet -Refrigeration, Turbo Expander, Joule Thompson are typical

Sales Compression Same as Sour Same as Sweet

Water Handling Stored in tanks that can be open to atmosphere and either treated or disposed

Stored in tanks that are not open to atmosphere and either treated or disposed

NGL/Condensate Handling Same as Sour Same as Sweet

LPG Handling Same as Sour Same as Sweet

Regulatory / Permitting Minimal barriers to entry of new plants

New sour processing plants must consider existing sulfur processing in order to minimize proliferation of sour plants

Costs Capital costs approximately $1MM / mmcf/d throughput

Capital costs range from $1.5MM / mmcf/d to $2.5MM / mmcf/d throughput

▶ Ability to process sour gas safely is a barrier to new market entrants

▶ SemCAMS is the largest licensed sour gas (gas containing significant amounts of H2S) processors in Alberta

▶ H2S is toxic and must be processed through a specialized method

▶ H2S can have a detrimental effect on the integrity of processing equipment, pipelines etc., if mishandled

▶ Due to the specialized handling required of sour gas, numerous regulatory precautions are applied to our facilities(1)

▶ SemCAMS has been safely processing sour gas for over 45 years with a top quartile safety performance when compared to industry benchmarks

1) Source: National Energy Board (“NEB”), Alberta Boilers Safety Association (“ABSA”), Energy Resources Convention Board (“ERCB”), Department of Fisheries and Oceans (“DFO”), Alberta Environment (“AENV”), Work Health and Safety (“WH&S”)

26

Legend

Sour Gas Processing

Gas

Water

Condensate

Acid Gas

NGLs

SemGroup Consolidated Balance Sheets

(in thousands, unaudited, condensed) June 30, 2018

December 31, 2017

ASSETSCurrent assets $ 695,864 $ 902,899Property, plant and equipment, net 3,415,505 3,315,131Goodwill and other intangible assets 639,142 655,945Equity method investments 276,120 285,281Other noncurrent assets, net 145,044 132,600Noncurrent assets held for sale — 84,961Total assets $ 5,171,675 $ 5,376,817

LIABILITIES, PREFERRED STOCK AND OWNERS' EQUITYCurrent liabilities:

Current portion of long-term debt $ 6,000 $ 5,525Other current liabilities 608,196 761,036

Total current liabilities 614,196 766,561

Long-term debt, excluding current portion 2,534,894 2,853,095Other noncurrent liabilities 90,937 85,080Noncurrent liabilities held for sale — 13,716Total liabilities 3,240,027 3,718,452

Preferred stock 347,130 —Owners' equity 1,584,518 1,658,365Total liabilities, preferred stock and owners' equity $ 5,171,675 $ 5,376,817

27

28

SemGroup Consolidated Statements of Operations and Comprehensive Income (Loss)

(in thousands, except per share amounts, unaudited, condensed) 2018 2017Q1 Q2 YTD Q1 Q2 Q3 Q4 FY2017

Revenues $ 661,609 $ 595,794 $ 1,257,403 $ 456,100 $ 473,089 $ 545,922 $ 606,806 $ 2,081,917Expenses:

Costs of products sold, exclusive of depreciation and amortization shown below 496,132 412,089 908,221 348,998 340,107 398,252 427,534 1,514,891Operating 69,791 90,245 160,036 52,083 73,346 62,666 66,669 254,764General and administrative 26,477 22,886 49,363 21,712 26,819 38,389 26,859 113,779Depreciation and amortization 50,536 51,755 102,291 24,599 25,602 50,135 58,085 158,421Loss (gain) on disposal or impairment, net (3,566) 1,824 (1,742) 2,410 (234) 41,625 (30,468) 13,333Total expenses 639,370 578,799 1,218,169 449,802 465,640 591,067 548,679 2,055,188

Earnings from equity method investments 12,614 14,351 26,965 17,091 17,753 17,367 15,120 67,331Operating income (loss) 34,853 31,346 66,199 23,389 25,202 (27,778) 73,247 94,060Other expenses, net 44,805 37,685 82,490 33,571 11,966 28,574 39,487 113,598Income (loss) from continuing operations before income taxes (9,952) (6,339) (16,291) (10,182) 13,236 (56,352) 33,760 (19,538)Income tax expense (benefit) 23,083 (3,613) 19,470 95 3,625 (37,249) 31,141 (2,388)Net income (loss) (33,035) (2,726) (35,761) (10,277) 9,611 (19,103) 2,619 (17,150)

Less: cumulative preferred stock dividends 4,832 6,211 11,043 — — — — —Net income (loss) attributable to common shareholders $ (37,867) $ (8,937) $ (46,804) $ (10,277) $ 9,611 $ (19,103) $ 2,619 $ (17,150)Net income (loss) $ (33,035) $ (2,726) $ (35,761) $ (10,277) $ 9,611 $ (19,103) $ 2,619 $ (17,150)Other comprehensive income (loss), net of income taxes 18,171 6,180 24,351 6,033 8,952 9,230 (4,102) 20,113Comprehensive income (loss) $ (14,864) $ 3,454 $ (11,410) $ (4,244) $ 18,563 $ (9,873) $ (1,483) $ 2,963

Net income (loss) per common share:Basic $ (0.48) $ (0.11) $ (0.60) $ (0.16) $ 0.15 $ (0.25) $ 0.03 $ (0.24)Diluted $ (0.48) $ (0.11) $ (0.60) $ (0.16) $ 0.15 $ (0.25) $ 0.03 $ (0.24)

Weighted average shares (thousands):Basic 78,198 78,319 78,259 65,692 65,749 75,974 78,189 71,418Diluted 78,198 78,319 78,259 65,692 66,277 75,974 78,749 71,418

29

SemGroup Non-GAAP Adjusted EBITDA Calculation

(in thousands, unaudited) 2018 2017Reconciliation of net income to Adjusted EBITDA: Q1 Q2 YTD Q1 Q2 Q3 Q4 FY2017Net income (loss) $ (33,035) $ (2,726) $ (35,761) $ (10,277) $ 9,611 $ (19,103) $ 2,619 $ (17,150)

Add: Interest expense 42,461 35,904 78,365 13,867 13,477 32,711 42,954 103,009Add: Income tax expense (benefit) 23,083 (3,613) 19,470 95 3,625 (37,249) 31,141 (2,388)Add: Depreciation and amortization expense 50,536 51,755 102,291 24,599 25,602 50,135 58,085 158,421

EBITDA 83,045 81,320 164,365 28,284 52,315 26,494 134,799 241,892Selected Non-Cash Items and

Other Items Impacting Comparability 10,326 17,690 28,016 32,383 13,095 64,239 (23,306) 86,411Adjusted EBITDA $ 93,371 $ 99,010 $ 192,381 $ 60,667 $ 65,410 $ 90,733 $ 111,493 $ 328,303

Selected Non-Cash Items andOther Items Impacting ComparabilityLoss (gain) on disposal or impairment, net $ (3,566) $ 1,824 $ (1,742) $ 2,410 $ (234) $ 41,625 $ (30,468) $ 13,333Foreign currency transaction loss (gain) 3,294 2,314 5,608 — (1,011) (747) (2,951) (4,709)Adjustments to reflect equity earnings on an EBITDA basis 4,883 4,886 9,769 6,709 6,692 6,678 6,811 26,890M&A transaction related costs 1,156 648 1,804 — 5,453 14,886 1,649 21,988Pension plan curtailment loss (gain) — — — — — (3,097) 89 (3,008)Employee severance and relocation expense 137 211 348 558 312 104 720 1,694Unrealized loss (gain) on derivative activities 2,226 4,409 6,635 27 (928) 1,833 (892) 40Non-cash equity compensation 2,196 3,398 5,594 2,757 2,803 2,957 1,736 10,253Loss on early extinguishment of debt — — — 19,922 8 — — 19,930Selected Non-Cash items and

Other Items Impacting Comparability $ 10,326 $ 17,690 $ 28,016 $ 32,383 $ 13,095 $ 64,239 $ (23,306) $ 86,411

SemGroup Non-GAAP Adjusted EBITDA Calculation(in thousands, unaudited) FY2016 FY2015 FY2014Reconciliation of net income to Adjusted EBITDA:Net income $ 13,262 $ 42,812 $ 52,057

Add: Interest expense 62,650 69,675 49,044Add: Income tax expense 11,268 33,530 46,513Add: Depreciation and amortization expense 98,804 100,882 98,397

EBITDA 185,984 246,899 246,011Selected Non-Cash Items and Other Items Impacting Comparability 96,811 58,383 41,430Adjusted EBITDA $ 282,795 $ 305,282 $ 287,441

Selected Non-Cash Items andOther Items Impacting ComparabilityLoss on disposal or impairment, net $ 16,048 $ 11,472 $ 32,592Loss from discontinued operations, net of income taxes 1 4 1Foreign currency transaction loss (gain) 4,759 (1,067) (86)Adjustments to reflect equity earnings on an EBITDA basis 28,757 32,965 11,033Remove loss (gain) on sale or impairment of NGL units 30,644 (14,517) (34,211)M&A transaction related costs 3,269 10,000 —Inventory valuation adjustments including equity method investees — 3,187 7,781Employee severance and relocation expense 2,128 90 220Unrealized loss (gain) on derivative activities 989 2,014 (1,734)Change in fair value of warrants — — 13,423Bankruptcy related expenses — 224 1,310Charitable contributions — — 3,379Legal settlement expense — 3,394 —Recovery of receivables written off at emergence — — (664)Non-cash equity compensation 10,216 10,617 8,386Selected Non-Cash items andOther Items Impacting Comparability $ 96,811 $ 58,383 $ 41,430

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SemCAMS Non-GAAP Financial Data Reconciliations

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