Table of Contents Table of Contents 2 List of Tables 4 List of Figures 5 Company Snapshot 8 Key Information 8 Company Overview 8 Clayton Williams Energy, Inc., Valuation and Financial Data 9 Clayton Williams Energy, Inc., Share Price Performance 9 Share Price Performance, Q2, 2015-Q2, 2016 9 Clayton Williams Energy, Inc., Key Valuation Metrics 10 Key Valuation Metrics, Q2, 2015-Q2, 2016 10 Clayton Williams Energy, Inc., Quarterly Results of Oil & Gas Operations Per boe Produced 11 Results of Oil & Gas Operations Per boe Produced, Q2, 2015-Q2, 2016 11 Results of Oil & Gas Operations Per boe Growth Rates, Q2, 2015-Q2, 2016 12 Clayton Williams Energy, Inc., Quarterly E&P Costs Trends 13 Upstream Capital Expenditure, Q2, 2015-Q2, 2016 13 Clayton Williams Energy, Inc., Quarterly Production Trends 14 Clayton Williams Energy, Inc., Total Oil and Gas Production 14 Total Crude Oil and Natural Gas Production Trend, Q2, 2015-Q2, 2016 14 Total Crude Oil & Natural Gas Production, By Country/Region, Q2, 2015-Q2, 2016 15 Clayton Williams Energy, Inc., Crude Oil Production 16 Total Crude Oil Production Trend, Q2, 2015-Q2, 2016 16 Crude Oil Production, By Country/Region, Q2, 2015-Q2, 2016 17 Clayton Williams Energy, Inc., Natural Gas Production 18 Total Natural Gas Production Trend, Q2, 2015-Q2, 2016 18 Natural Gas Production, By Country/Region, Q2, 2015-Q2, 2016 19 Clayton Williams Energy, Inc., Valuation and Financial Data, 2011-2015 20 Clayton Williams Energy, Inc., Share Price Performance, 2011-2015 20 Share Price Performance, 2011-2015 20 Key Valuation Metrics, 2011-2015 21 Clayton Williams Energy, Inc., Production and Reserves Trends 22 Total Oil and Gas, Reserves and Production 22 Total Crude Oil and Natural Gas Production and Reserves Trend, 2011-2015 22 Total Crude Oil & Natural Gas Production and Reserves By Country/Region, 2011-2015 24 Total Crude Oil and Natural Gas Reserve Changes, 2011-2015 26 Crude Oil/Liquids Production and Reserve 27 Crude Oil/Liquids Production and Reserve Trend, 2011-2015 27 Crude Oil Production and Reserves By Country/Region, 2011-2015 28 Crude Oil/Liquids Reserve Changes, 2011-2015 30 Natural Gas Production and Reserve 31 Natural Gas Production and Reserve Trend, 2011-2015 31 Natural Gas Production and Reserves, By Country/Region, 2011-2015 32 Natural Gas Reserve Changes, 2011-2015 34 Total Crude Oil and Natural Gas Reserves Life Index 35 Total Crude Oil and Natural Gas Reserves Life Index, 2011-2015 35 Total Crude Oil and Natural Gas Reserves Life Index, By Country/Region, 2011-2015 36 Clayton Williams Energy, Inc., E&P Costs Trends 38 Allocation of the Upstream Capital Expenditure 38 Upstream Capital Expenditure, 2011-2015 38 Acquisition Costs By Country/Region, 2011-2015 39 Exploration and Development Costs, By Country/Region, 2011-2015 40 Oil and Gas Cost Per boe, US$/boe 42 Oil and Gas Cost Per boe, US$/boe, 2011-2015 42 Oil and Gas Cost Per boe, US$/boe, By Country/Region, 2011-2015 44 Clayton Williams Energy, Inc., Reserve Replacement Ratio 46 Oil and Gas Production Replacement Ratio 46 Oil and Gas Production Replacement Ratio, 2011-2015 46 Oil and Gas Production Replacement Ratio, By Country/Region, 2011-2015 48 Clayton Williams Energy, Inc., Results of Oil & Gas Operations Trend 52 Oil and Gas Revenue and Expenses 52 Oil and Gas Revenue and Expenses, 2011-2015 52 Oil and Gas Revenue and Expenses, By Country/Region, 2011-2015 53 Oil and Gas Revenue and Expenses, Per boe 57 Oil and Gas Revenue and Expenses, By boe, 2011-2015 57 Oil and Gas Revenue and Expenses Per boe, By Country/Region, 2011-2015 58 Oil and Gas Performance Metrics 62 Clayton Williams Energy, Inc., Land Holdings and Well Data 63 Developed and Undeveloped Acreage 63 Gross and Net Developed and Undeveloped Acreage, 2011-2015 63 Gross and Net Developed and Undeveloped Acreage, By Country/Region, 2011-2015 64 Well Statistics 67 Producible Oil and Gas Well, 2011-2015 67 Producible Oil and Gas Well, By Country/Region, 2011-2015 68 Exploration and Development Wells Drilled, 2011-2015 72 Recent Developments 74 Clayton Williams Energy, Inc. - Recent Developments 74 Aug 05, 2016: Clayton Williams Energy Revised Second Quarter And Six Months 2016 GAAP Net Loss 74 Aug 03, 2016: Clayton Williams Energy Provides An Update On Its Development Plans And Operations 74 Aug 03, 2016: Clayton Williams Energy Announces Second Quarter 2016 Financial Results 75 May 04, 2016: Clayton Williams Energy Announces First Quarter 2016 Financial Results 77 Mar 31, 2016: Clayton Williams Energy Announces Changes To Its Board Of Directors 78 Mar 15, 2016: Clayton Williams Energy Announces Recent Hedging Transactions 79 Mar 10, 2016: Clayton Williams Energy Announces 2015 Financial Results And Year-End Reserves 79 Jan 18, 2016: Clayton Williams Energy Provides Update On Recent Transactions 83 Nov 04, 2015: Clayton Williams Energy Announces Third Quarter 2015 Financial Results 84 Oct 14, 2015: Clayton Williams Energy Announces Board Review Of Strategic Alternatives 85 Appendix 86 Methodology 86 Coverage 86 Secondary Research 86 Primary Research 86 Data Information Sources 87 Company Source 87 SEC/Other Regulatory Filings 87 Other Sources 87 Expert Panel Validation 87 Data Definition 87 Oil and Gas Reserves 87 Units of Measure 88 About GlobalData 88 Disclosure 88 Disclaimer 88

List of Tables Table 1: Clayton Williams Energy, Inc., Key Facts 8 Table 2: Clayton Williams Energy, Inc., Share Price Performance, Q2, 2015-Q2, 2016 9 Table 3: Clayton Williams Energy, Inc., Key Valuation Metrics, Q2, 2015-Q2, 2016 10 Table 4: Clayton Williams Energy, Inc., Results of Oil & Gas Operations Per boe Produced, US$/boe, Q2, 2015-Q2, 2016 11 Table 5: Clayton Williams Energy, Inc., Results of Oil & Gas Operations Per boe Growth Rates, %, Q2, 2015-Q2, 2016 12 Table 6: Clayton Williams Energy, Inc., Upstream Capital Expenditure, Q2, 2015-Q2, 2016 13 Table 7: Clayton Williams Energy, Inc., Total Crude Oil and Natural Gas, Production, Q2, 2015-Q2, 2016 14 Table 8: Clayton Williams Energy, Inc., Total Oil & Gas Production, By Country/Region, mmboe, Q2, 2015-Q2, 2016 15 Table 9: Clayton Williams Energy, Inc., Total Crude Oil Production, mmbbl, Q2, 2015-Q2, 2016 16 Table 10: Clayton Williams Energy, Inc., Crude Oil Production, By Country/Region, mmbbl, Q2, 2015-Q2, 2016 17 Table 11: Clayton Williams Energy, Inc., Total Natural Gas Production, bcf, Q2, 2015-Q2, 2016 18 Table 12: Clayton Williams Energy, Inc., Natural Gas Production, By Country/Region, bcf, Q2, 2015-Q2, 2016 19 Table 13: Clayton Williams Energy, Inc., Share Price Performance, 2011-2015 20 Table 14: Clayton Williams Energy, Inc., Key Valuation Metrics, 2011-2015 21 Table 15: Clayton Williams Energy, Inc., Total Crude Oil and Natural Gas, Production and Reserves, mmboe, 2011-2015 23 Table 16: Clayton Williams Energy, Inc., Total Crude Oil & Natural Gas Production and Reserves, By Country/Region, mmboe, 2011-2015 25 Table 17: Clayton Williams Energy, Inc., Total Crude Oil and Natural Gas Reserve Changes, mmboe, 2011-2015 26 Table 18: Clayton Williams Energy, Inc., Crude Oil Production and Reserves Metrics, mmbbl, 2011-2015 27 Table 19: Clayton Williams Energy, Inc., Crude Oil Production and Reserves, By Country/Region, mmbbl, 2011-2015 29 Table 20: Clayton Williams Energy, Inc., Crude Oil Reserve Changes, mmbbl, 2011-2015 30 Table 21: Clayton Williams Energy, Inc., Natural Gas Production and Reserves Metrics, bcf, 2011-2015 31 Table 22: Clayton Williams Energy, Inc., Natural Gas Production and Reserves, By Country/Region, bcf, 2011-2015 33 Table 23: Clayton Williams Energy, Inc., Natural Gas Reserve Changes, bcf, 2011-2015 34 Table 24: Clayton Williams Energy, Inc., Oil and Gas Reserves Life Index, Years, 2011-2015 35 Table 25: Clayton Williams Energy, Inc., Oil and Gas Reserves Life Index, By Country/Region, Years, 2011-2015 37 Table 26: Clayton Williams Energy, Inc., Upstream Capital Expenditure, US$ mil, 2011-2015 38 Table 27: Clayton Williams Energy, Inc., Proved and Unproved Acquisition Costs, By Country/Region, US$ mil, 2011-2015 39 Table 28: Clayton Williams Energy, Inc., Exploration and Development Costs, By Country/Region, US$ mil, 2011-2015 41 Table 29: Clayton Williams Energy, Inc., Reserves Replacement, Finding and Development Costs, Finding Cost and Proved Acquisition Costs Per boe, US$/boe, 2011-2015 43 Table 30: Clayton Williams Energy, Inc., Reserves Replacement, Finding and Development Costs, Finding Cost and Proved Acquisition Costs Per boe, US$/boe, By Country/Region, 2011-2015 45 Table 31: Clayton Williams Energy, Inc., Oil and Gas Production Replacement Ratio, %, 2011-2015 47 Table 32: Clayton Williams Energy, Inc., 3-Year Wt.Avg. Oil and Gas Production Replacement Ratio, By Country/Region, %, 2011-2015 51 Table 33: Clayton Williams Energy, Inc., Revenue and Expenses, US$ mil, 2011-2015 52 Table 34: Clayton Williams Energy, Inc., Revenue and Expenses, By Country/Region, US$ mil, 2011-2015 56 Table 35: Clayton Williams Energy, Inc., Oil and Gas Revenue and Expenses, US$/boe, 2011-2015 57 Table 36: Clayton Williams Energy, Inc., Oil and Gas Revenue and Expenses, US$/boe, By Country/Region, 2011-2015 61 Table 37: Clayton Williams Energy, Inc., Oil and Gas Performance Metrics, 2011-2015 62 Table 38: Clayton Williams Energy, Inc., Land Holdings (Developed and Undeveloped Acreage), Acres, 2011-2015 63 Table 39: Clayton Williams Energy, Inc., Land Holdings (Developed and Undeveloped Acreage), By Country/Region, Acres, 2011-2015 66 Table 40: Clayton Williams Energy, Inc., Producible Oil and Gas Wells, 2011-2015 67 Table 41: Clayton Williams Energy, Inc., Producible Oil and Gas Wells, By Country/Region, 2011-2015 71 Table 42: Clayton Williams Energy, Inc., Exploratory and Developed Wells, 2011-2015 73 List of Figures Figure 1: Clayton Williams Energy, Inc., Share Price Performance, USD/Share, Q2, 2015-Q2, 2016 9 Figure 2: Clayton Williams Energy, Inc., Key Valuation Metrics, EV/Production ($/boed), EV/Proved Reserve ($/boe), Q2, 2015-Q2, 2016 10 Figure 3: Clayton Williams Energy, Inc., Results of Oil & Gas Operations Per boe Produced, US$/boe, Q2, 2015-Q2, 2016 11 Figure 4: Clayton Williams Energy, Inc., Upstream Capital Expenditure, US$ mil, Q2, 2015-Q2, 2016 13 Figure 5: Clayton Williams Energy, Inc., Total Crude Oil and Natural Gas, Production, mmboe, Q2, 2015-Q2, 2016 14 Figure 6: Clayton Williams Energy, Inc., Total Oil & Gas Production, By Country/Region, mmboe, Q2, 2015-Q2, 2016 15 Figure 7: Clayton Williams Energy, Inc., Total Crude Oil Production, mmbbl, Q2, 2015-Q2, 2016 16 Figure 8: Clayton Williams Energy, Inc., Crude Oil Production, By Country/Region, mmbbl, Q2, 2015-Q2, 2016 17 Figure 9: Clayton Williams Energy, Inc., Total Natural Gas Production, bcf, Q2, 2015-Q2, 2016 18 Figure 10: Clayton Williams Energy, Inc., Natural Gas Production, By Country/Region, bcf, Q2, 2015-Q2, 2016 19 Figure 11: Clayton Williams Energy, Inc., Share Price Performance, USD/Share, 2011-2015 20 Figure 12: Clayton Williams Energy, Inc., Key Valuation Metrics, EV/Production ($/boed), EV/Proved Reserve (US$/boe), 2011-2015 21 Figure 13: Clayton Williams Energy, Inc., Total Crude Oil and Natural Gas, Production and Reserves, mmboe, 2011-2015 22 Figure 14: Clayton Williams Energy, Inc., Total Oil & Gas Reserves, End of Period, By Country/Region, mmboe, 2011-2015 24 Figure 15: Clayton Williams Energy, Inc., Total Oil & Gas Production, By Country/Region, mmboe, 2011-2015 24 Figure 16: Clayton Williams Energy, Inc., Total Crude Oil and Natural Gas Reserve Changes, mmboe, 2015 26 Figure 17: Clayton Williams Energy, Inc., Crude Oil Production and Reserves Metrics, mmbbl, 2011-2015 27 Figure 18: Clayton Williams Energy, Inc., Oil Reserves, End of Period, By Country/Region, mmbbl, 2011-2015 28 Figure 19: Clayton Williams Energy, Inc., Oil Production, By Country/Region, mmbbl, 2011-2015 28 Figure 20: Clayton Williams Energy, Inc., Crude Oil Reserve Changes, mmbbl, 2015 30 Figure 21: Clayton Williams Energy, Inc., Natural Gas Production and Reserves Metrics, bcf, 2011-2015 31 Figure 22: Clayton Williams Energy, Inc., Gas Reserves, End of Period, By Country/Region, bcf, 2011-2015 32 Figure 23: Clayton Williams Energy, Inc., Gas Production, By Country/Region, bcf, 2011-2015 32 Figure 24: Clayton Williams Energy, Inc., Natural Gas Reserve Changes, bcf, 2015 34 Figure 25: Clayton Williams Energy, Inc., Oil and Gas Reserves Life Index, Years, 2011-2015 35 Figure 26: Clayton Williams Energy, Inc., Gas Reserve Life Index, By Country/Region, Years, 2011-2015 36 Figure 27: Clayton Williams Energy, Inc., Oil & Gas Reserve Life Index, By Country/Region, Years, 2011-2015 36 Figure 28: Clayton Williams Energy, Inc., Oil Reserve Life Index, By Country/Region, Years, 2011-2015 37 Figure 29: Clayton Williams Energy, Inc., Upstream Capital Expenditure, US$ mil, 2011-2015 38 Figure 30: Clayton Williams Energy, Inc., Unproved Acquisition Costs, By Country/Region, US$ mil, 2011-2015 39 Figure 31: Clayton Williams Energy, Inc., Development Costs, By Country/Region, US$ mil, 2011-2015 40 Figure 32: Clayton Williams Energy, Inc., Exploration Costs, By Country/Region, US$ mil, 2011-2015 40 Figure 33: Clayton Williams Energy, Inc., 3-Year Wt.Avg., Reserves Replacement, Finding and Development Costs, Finding Cost and Proved Acquisition Costs Per boe, US$/boe, 2011-2015 42 Figure 34: Clayton Williams Energy, Inc., Oil & Gas Finding & Development Cost/boe, 3-Year Average, By Country/Region, US$/boe, 2011-2015 44 Figure 35: Clayton Williams Energy, Inc., Oil & Gas Finding Cost per boe, 3-Year Average, By Country/Region, US$/boe, 2011-2015 44 Figure 36: Clayton Williams Energy, Inc., Reserve Replacement Cost per boe, 3-Year Average, By Country/Region, US$/boe, 2011-2015 45 Figure 37: Clayton Williams Energy, Inc., 3-Year Wt.Avg., Oil and Gas Production Replacement Ratio, %, 2011-2015 46 Figure 38: Clayton Williams Energy, Inc., 3-Year Wt. Avg. Gas F&D Production Replacement, By Country/Region, %, 2011-2015 48 Figure 39: Clayton Williams Energy, Inc., 3-Year Wt. Avg. Gas RRC Production Replacement, By Country/Region, %, 2011-2015 48 Figure 40: Clayton Williams Energy, Inc., 3-Year Wt. Avg. Oil & Gas F&D Production Replacement, By Country/Region, %, 2011-2015 49 Figure 41: Clayton Williams Energy, Inc., 3-Year Wt. Avg. Oil & Gas RRC Production Replacement, By Country/Region, %, 2011-2015 49 Figure 42: Clayton Williams Energy, Inc., 3-Year Wt. Avg. Oil F&D Production Replacement, By Country/Region, %, 2011-2015 50 Figure 43: Clayton Williams Energy, Inc., 3-Year Wt. Avg. Oil RRC Production Replacement, By Country/Region, %, 2011-2015 50 Figure 44: Clayton Williams Energy, Inc., Revenue and Expenses, US$ mil, 2011-2015 52 Figure 45: Clayton Williams Energy, Inc., Exploration Expenses, By Country/Region, US$ mil, 2011-2015 53 Figure 46: Clayton Williams Energy, Inc., Income Tax Provision (Benefit) From Upstream Oil & Gas Operations, By Country/Region, US$ mil, 2011-2015 53 Figure 47: Clayton Williams Energy, Inc., Net Income/ Loss From Upstream Oil & Gas Operations, By Country/Region, US$ mil, 2011-2015 54 Figure 48: Clayton Williams Energy, Inc., Oil & Gas Revenue, By Country/Region, US$ mil, 2011-2015 54 Figure 49: Clayton Williams Energy, Inc., Profit (loss) Before Taxation From Upstream Oil & Gas Operations, By Country/Region, US$ mil, 2011-2015 55 Figure 50: Clayton Williams Energy, Inc., Production Costs, By Country/Region, US$ mil, 2011-2015 55 Figure 51: Clayton Williams Energy, Inc., Total Expenses From Upstream Oil & Gas Operations, By Country/Region, US$ mil, 2011-2015 56 Figure 52: Clayton Williams Energy, Inc., Oil and Gas Revenue and Expenses, US$/boe, 2011-2015 57 Figure 53: Clayton Williams Energy, Inc., Exploration Expenses per boe, By Country/Region, US$/boe, 2011-2015 58 Figure 54: Clayton Williams Energy, Inc., Income Tax/(Benefit) per boe, By Country/Region, US$/boe, 2011-2015 58 Figure 55: Clayton Williams Energy, Inc., Lifting Cost per boe, By Country/Region, US$/boe, 2011-2015 59 Figure 56: Clayton Williams Energy, Inc., Annual Net Income per boe, By Country/Region, US$/boe, 2011-2015 59 Figure 57: Clayton Williams Energy, Inc., Oil & Gas Revenue per boe, By Country/Region, US$/boe, 2011-2015 60 Figure 58: Clayton Williams Energy, Inc., Total DD&A per boe, By Country/Region, US$/boe, 2011-2015 60 Figure 59: Clayton Williams Energy, Inc., Total Revenue per boe, By Country/Region, US$/boe, 2011-2015 61 Figure 60: Clayton Williams Energy, Inc., Oil and Gas Performance Metrics, 2011-2015 62 Figure 61: Clayton Williams Energy, Inc., Land Holdings (Developed and Undeveloped Acreage), Acres, 2011-2015 63 Figure 62: Clayton Williams Energy, Inc., Total Gross Undeveloped Acreage, By Country/Region, Acres, 2011-2015 64 Figure 63: Clayton Williams Energy, Inc., Total Net Undeveloped Acreage, By Country/Region, Acres, 2011-2015 64 Figure 64: Clayton Williams Energy, Inc., Total Gross Developed Acreage, By Country/Region, Acres, 2011-2015 65 Figure 65: Clayton Williams Energy, Inc., Total Net Developed Acreage, By Country/Region, Acres, 2011-2015 65 Figure 66: Clayton Williams Energy, Inc., Producible Oil and Gas Wells, 2011-2015 67 Figure 67: Clayton Williams Energy, Inc., Gross Productive Gas Wells, By Country/Region, Number, 2011-2015 68 Figure 68: Clayton Williams Energy, Inc., Gross Productive Oil & Gas Wells, By Country/Region, Number, 2011-2015 68 Figure 69: Clayton Williams Energy, Inc., Gross Productive Oil Wells, By Country/Region, Number, 2011-2015 69 Figure 70: Clayton Williams Energy, Inc., Net/Gross Oil & Gas Ratio, By Country/Region, %, 2011-2015 69 Figure 71: Clayton Williams Energy, Inc., Net Productive Gas Wells, By Country/Region, Number, 2011-2015 70 Figure 72: Clayton Williams Energy, Inc., Net Productive Oil & Gas Wells, By Country/Region, Number, 2011-2015 70 Figure 73: Clayton Williams Energy, Inc., Net Productive Oil Wells, By Country/Region, Number, 2011-2015 71 Figure 74: Clayton Williams Energy, Inc., Exploratory and Developed Wells, 2011-2015 72