MIDSTREAM PARTNERS CHESAPEAKE MIDSTREAM DEVELOPMENT ACQUISITION DECEMBER 11, 2012 . . TRANSACTION OVERVIEW ACMP Acquisition of CHK Midstream Assets (CMD)  ACMP to acquire a substantial majority of Chesapeake Energy’s remaining midstream assets (“CMD”) for $2.16 billion  Unique opportunity to accelerate ACMP’s drop down story   WMB Strategic Investment in ACMP  The Williams Companies, Inc. (“WMB”) to partner with GIP, enhancing sponsorship of ACMP   Substantial GIP and WMB Equity Commitment Partnership establishes a significant footprint in leading unconventional basins Enhances strategic scale and diversity WMB to acquire 50% of ACMP GP and ~23% of LP Units; an endorsement of ACMP’s strategic platform and potential Leading midstream operational and development capabilities complement ACMP’s already strong position  Sponsors investing new long-term equity in transaction – $1.16 billion committed   Equity structured with PIK and subordinated features to support near-term build out of gathering and processing platform Demonstrates commitment to ACMP’s long term success 2 KEY TRANSACTION HIGHLIGHTS CMD Areas of Operation Key Transaction Highlights      Expanding Footprint and Scale  Strong Sponsorship from GIP / WMB Increased Diversification Low Risk Contract Structure Predictable Cash Flow Growth High Quality Organic Growth Platform 3 TRANSACTION HIGHLIGHTS EXPANDS SCALE AND DIVERSITY WITH STRATEGIC SPONSOR SUPPORT Expanding Footprint and Scale   Creates the largest gathering and processing MLP measured by volume and invested capital Addition of CMD midstream assets positions ACMP among largest midstream MLPs Increased Diversification   Adds significant acreage dedications in key unconventional basins Enhanced exposure to oil/liquids focused drilling and entry into gas processing segment of the value chain  Low-risk gathering and processing contracts with appropriate downside protection that provide stable cash flow profile No direct commodity exposure in all basins with contractual features supporting cash flow generation Low Risk Contract Structure Predictable Cash Flow Growth High Quality Organic Growth Platform Strong Sponsorship from GIP / WMB    Contractual features deliver predictable, growing cash flows Near-term contractual downside protection provides near-term revenue risk mitigation   Industry leading long-term organic growth project pipeline Substantial growth capex expected to be deployed in the next five years, earning a contractual mid-teens return   Significant incremental equity investment from strong sponsors in GIP and WMB Williams adds vast expertise across the midstream value chain for natural gas and NGLs with its significant strategic investment and endorsement of ACMP 4 SCALE OF ACMP OPERATIONS ACMP IS THE LARGEST G&P MLP MEASURED BY VOLUME AND INVESTED CAPITAL 3Q 2012 PF Average Daily Throughput of Gathering Assets Key Operating Data(1) Mmcfe/d Current 4,500 Pro Forma 7 10 4,000 Basins 3,500 Invested Capital: $3.8 billion $6.0 billion 3,000 4.4 million 8.7 million 2,500 Dedicated Acreage: 2,000 Miles of Pipe: 4,155 5,828 Volume: (mmcf/d) 2,825 3,909 Wells Gathered: 5,808 8,603 533 1,124 1,500 1,000 500 0 Direct Employees: (1) ACMP NGLS XTEX DPM MWE RGP WES CPNO CMLP APL (1) Data for 3 months ending 9/30/12 from quarterly filings and is pro-forma to include CMD throughput. 1. Actual throughput volumes of 2,802MMcf/d; contribution from dropped assets of ~574MMcf/d. 5 BASIN AND CUSTOMER DIVERSIFICATION EXPANDING ACCESS TO BASINS AND CUSTOMER BASE  Growth from seven to ten basins  Greater geographic diversity Current ACMP Assets Pro Forma ACMP Assets Pro Forma ACMP Customer Base  Chesapeake  ExxonMobil  Statoil  Total  Anadarko  Shell  Mitsui  Enervest 6 BASIN DIVERSIFICATION BROAD EXPOSURE TO WET GAS, OIL, AND DRY GAS RESOURCE PLAYS Barnett Marcellus Mid-Continent Haynesville Eagle Ford Utica Niobrara Dry Gas Dry Gas; Wet Gas Dry Gas; Wet Gas; Oil Dry Gas Wet Gas; Oil Dry Gas; Wet Gas; Oil Wet Gas; Oil 1,236 MMcfd 717 MMcfd 573 MMcfd 1,189 MMcfd 158 MMcfd 26 MMcfd 10 MMcfd 931,000 / 931,000 1,329,000 / 1,740,000 1,964,000 / 1,964,000 209,000 / 547,000 0/ 1,382,000 0/ 1,846,000 0/ 311,000 Business Lines Gas Gathering; Treating; Compression Gas Gathering; Compression Gas Gathering; Treating; Compression Gas Gathering; Treating; Compression Gas Gathering; Treating; Compression Gas Gathering; Treating; Compression; Gas Processing and Fractionation Gas Gathering; Treating; Compression; Gas Processing Contract Terms MVC and Fee Redetermination Cost of Service and EBITDA Guaranty Annual Fee Redetermination Annual Fee Redetermination / MVC and Fee Tiers Cost of Service and Fee Tiers Cost of Service (gathering) / Fixed-Fee (processing) Cost of Service Basin Characteristics Gas Gathered (3Q 2012) Existing Dedication Current / Pro Forma (acres) 7 CONTRACT STRUCTURE PREDICTABLE BUSINESS MODEL EXTENDS TO NEW BASINS ACMP Haynesville Eagle Ford Utica Niobrara Direct Commodity Price Exposure None None None None None Contract Structure Cost of Service, Fee Redetermination, MVC Fixed Fee with MVC and Fee Tiers Cost of Service and Fee Tiers Cost of Service (gathering) / Fixed Fee (processing) Cost of Service Re-Contracting 15 – 20 Year Acreage Dedications 20 Year Acreage Dedication 20 Year Acreage Dedication 15-20 Year Acreage Dedication 20 Year Acreage Dedication Volume Protection MVC, Fee Redetermination, EBITDA Commitment 5 Year MVC, Fee Tiers Two Year Fee Tiers, Cost of Service Cost of Service (gathering only) Cost of Service Inflation Protection Escalation, Cost of Service 2.5% Fee Escalation Cost of Service Cost of Service (gathering) / 1.5% Fee Escalation (processing) Cost of Service Capital Protection Cost of Service, Fee Redetermination Annual Fee Redetermination Cost of Service Cost of Service (gathering only) Cost of Service Business Model Provides Low Risk, Visible Distributions 8 STRONG SPONSORSHIP SPONSORS BRING COMBINATION OF OPERATIONAL AND FINANCIAL EXPERTISE AND RESOURCES  WMB – Leading Midstream Player GIP – Leading Infrastructure Investor Significant Sponsor Equity Commitment     Williams provides an established history of managing, developing and completing large scale organic projects within the midstream sector Williams’ management team adds further operational and development experience Potential to expand services to new customer base Ability to take advantage of shared services Benefit from best practices from industry leader    Energy sector expertise combined with industrial operational management Global infrastructure fund manager with over $15 billion under management Energy investments include ACMP, Ruby Pipeline, Transitgas Pipeline, TerraGen Power and Channelview Cogeneration    GIP and WMB committing $1.16 billion to transaction funding Sponsor equity structured for long-term to support transaction Significant WMB strategic investment provides endorsement of transaction 9 PARTNERSHIP STRUCTURE STRATEGIC GENERAL PARTNERS; STRONG GOVERNANCE Pre-Transaction Structure Global Infrastructure Partners II LP units 50% Pro Forma ACMP Structure Global Infrastructure Partners I 50% Global Infrastructure Partners II LP units PIK units LP units Access Midstream Partners, LP (NYSE:ACMP) Existing Operating Assets (Barnett, Marcellus, Haynesville, Mid-Continent) 50% 50% LP units PIK units Access Midstream Partners GP, LLC Access Midstream Partners GP, LLC 100% of 2% GP interest + IDRs The Williams Companies, Inc Public Common Unit Holders 100% of 2% GP interest + IDRs LP units Public Common Unit Holders LP units Access Midstream Partners, LP (NYSE:ACMP) Existing Operating Assets Chesapeake Midstream Development “CMD” “MidContinent” Potential 1Q ‘13 Transaction 10 ACQUISITION FUNDING  Debt financing backstopped by $1.0 billion bridge facility commitment  Equity financing backstopped by $1.16 billion commitments from sponsors  Expect to close by end of 2012 – regulatory approvals complete Sources ($MM) Uses ($MM) Bridge Facility Sponsor Equity Commitments $1,000.0 1,160.0 CMD Acquisition $2,160.0 Total $2,160.0 Total $2,160.0 11 FINANCIAL OUTLOOK POST-ACQUISITION ACMP FINANCIAL OUTLOOK 2013/2014 ACMP Financial Outlook 2013 ($ million) 2014 Pre-Acquisition Post-Acquisition Pre-Acquisition Post-Acquisition EBITDA 550 - 575 800 – 850 600-650 1,000 – 1,100 Growth Capital 550 - 600 1,600 – 1,700 300-325 1,000 – 1,100 ~74 ~110 ~74 ~110 Maintenance Capital CMD transaction will allow sustained 15% annual distribution growth 12 MIDSTREAM PARTNERS APPENDIX CMD EAGLE FORD OVERVIEW LIQUIDS RICH BASIN Asset Map Asset Summary Resource Associated Gas (Oil), Wet Gas Services Gathering, Compression, Treating Gas Gathering Systems Amine Treater (H2S) Miles of Pipeline (In-Service) Gas Delivery Points Gas Gathered (3Q 2012) 12 1 (30 MMcf/d) 615.8 18 158 MMcf/d Contract Structure Cost of Service, Fee Tiers in 2013, 2014 Dedicated Acreage 1,382,000 14 CMD UTICA GATHERING SYSTEM OVERVIEW WET GAS, DRY GAS AND NGL SERVICES Asset Map Asset Summary Asset Cardinal Gas Services (“CGS”) Utica Gas Services (“UGS”) Resource Associated Gas (Oil), Wet Gas Dry Gas Services Gathering, Compression, Dehydration Gathering, Compression, Dehydration Gas Gathering Systems 5 4 CDP / Interconnect 2 1 44.2 8.1 Delivery Points 5 1 Gas Gathered (3Q 2012) 23 MMcf/d 3 MMcf/d CMD – 66%, Operator TOTAL – 25% EnerVest – 9% 100% CMD owned and operated Contract Structure Cost of Service Cost of Service Dedicated Acreage 1,453,000 393,000 Miles of Pipeline (In-Service) Ownership 15 CMD UTICA EAST OHIO PROCESSING OVERVIEW PROCESSING DEDICATION IN WET GAS WINDOW Asset Map Project Summary Current Status Processing Plants Under Construction 3 (200 MMcf/d each) Fractionation 90,000 Bbl/d (C2+) NGL Storage 870,000 Bbls Propane – 450,000 Bbls Butane – 300,000 Bbls Natural Gasoline – 120,000 Bbls Processing Spine Pipeline NGL Pipeline 24” processing spine pipeline 12” NGL pipeline Residue Gas Delivery Points 2 NGL Delivery Points 2 Contract Structure Fixed Fee with capex protection Ownership CMD – 49% Momentum – 30% EnerVest – 21% 16 CMD NIOBRARA OVERVIEW LIQUIDS-RICH GATHERING & PROCESSING DEDICATION WITH COST OF SERVICE CONTRACT STRUCTURE Asset Map Asset Summary Resource Associated Gas (Oil), Wet Gas Services Gathering, Compression, Processing Gas Gathering Systems Miles of Pipeline (In-Service) 2 60.1 Delivery Points 2 Gas Gathered (3Q 2012) 10 MMcf/d Contract Structure Cost of Service Dedicated Acreage 311,000 Ownership CMD – 50% RKI Exploration – 50% 17 CMD HAYNESVILLE OVERVIEW MATURE ASSET WITH CONTRACTUAL PROTECTION Asset Map Asset Summary Resource Dry Gas Services Gathering, Compression, Treating Gas Gathering Systems 4 Treating Facilities North DeSoto: 550 MMcf/d Converse: 330 MMcf/d Freeman: 120 MMcf/d Miles of Pipeline 325.3 (In-Service) Delivery Points 7 Gas Gathered 864 MMcf/d (3Q 2012) Contract Structure Fixed fee with MVC and fee tiers Dedicated Acreage 338,000 18 CMD MARCELLUS OVERVIEW INCREMENTAL MARCELLUS DEDICATION Asset Summary Asset Map Resource Dry Gas Services Gathering, Compression Low Pressure Gas Gathering Systems 24 CDP / Interconnect 24 Miles of Pipeline 619.2 Miles of Pipeline 0 (In-Service) (Construction or Route Dev.) Compressor Stations Gas Gathered (3Q 2012) Ownership Dedicated Acreage 13 26 MMcf/d 100% 411,000 19 FORWARD-LOOKING STATEMENTS Certain statements and information in this presentation may constitute forward-looking statements. The words “believe,” “expect,” “anticipate,” “plan,” “intend,” foresee,” “should,” “would,” “could,” or similar expressions are intended to identify forward-looking statements, which are generally not historical in nature. These forward-looking statements are based on current expectations and beliefs concerning future developments and their potential effect on us. While management believes that these forward-looking statements are reasonable as and when made, there can be no assurance that future developments affecting us will be those that we anticipate. All comments concerning our expectations for future revenues and operating results are based on our forecasts for our existing operations and do not include the potential impact of any future acquisitions. Our forward-looking statements involve significant risks and uncertainties (some of which are beyond our control) and assumptions that could cause actual results to differ materially from our historical experience and our present expectations or projections. Important factors that could cause actual results to differ materially from those in the forward-looking statements include, but are not limited to, those summarized below: • dependence on Chesapeake Energy Corporation (“Chesapeake” or “CHK”), Total E&P USA, Inc. (“Total”) and other producers for a substantial majority of our revenues; • the impact on our growth strategy and ability to increase cash distributions if Chesapeake, Total or other producers do not increase the volume of natural gas they provide to our gathering systems; • oil and natural gas realized prices; • the termination of our gas gathering agreements with Chesapeake or Total; • the availability, terms and effects of acquisitions from Chesapeake; • our potential inability to maintain existing distribution amounts or pay the minimum quarterly distribution to our unitholders; • the limitations that Chesapeake’s and our own level of indebtedness may have on our financial flexibility; • our ability to obtain new sources of natural gas, which is dependent on factors largely beyond our control; • the availability of capital resources to fund capital expenditures and other contractual obligations, and our ability to access those resources through the debt or equity capital markets; • competitive conditions; • the unavailability of third-party pipelines interconnected to our gathering systems or the potential that the volumes we gather do not meet the quality requirement of such pipelines; • new asset construction may not result in revenue increases and will be subject to regulatory, environmental, political, legal and economic risks; • our exposure to direct commodity price risk may increase in the future; • our ability to maintain and/or obtain rights to operate our assets on land owned by third parties; • hazards and operational risks that may not be fully covered by insurance; • our dependence on Chesapeake for substantially all of our compression capacity; • our lack of industry diversification; and • legislative or regulatory changes, including changes in environmental regulations, environmental risks, regulations by FERC and liability under federal and state environmental laws and regulations. Other factors that could cause our actual results to differ from our projected results are described in our 2011 Form 10-K and our other SEC filings. Individuals are cautioned not to place undue reliance on forward-looking statements, which speak only as of the date hereof. We undertake no obligation to publicly update or revise any forward-looking statements after the date they are made, whether as a result of new information, future events or otherwise. 20