LAND APPLICATION OF DRILLING MUD FROM OIL AND GAS EXPLORATION: AGRONOMIC AND ENVIRONMENTAL IMPLICATIONS By ANDREW HAYS WHITAKER Bachelor of Science in Plant and Soil Sciences Oklahoma State University Stillwater, OK 2012 Submitted to the Faculty of the Graduate College of the Oklahoma State University in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE May, 2014 LAND APPLICATION OF DRILLING MUD FROM OIL AND GAS EXPLORATION: AGRONOMIC AND ENVIRONMENTAL IMPLICATIONS Thesis Approved: Dr. Chad Penn Thesis Adviser Dr. Hailin Zhang Dr. Jason Warren . ii Name: ANDREW HAYS WHITAKER Date of Degree: MAY, 2014 Title of Study: LAND APPLICATION OF DRILLING MUD FROM OIL AND GAS EXPLORATION: AGRONOMIC AND ENVIRONMENTAL IMPLICATIONS Major Field: PLANT AND SOIL SCIENCES Abstract: Waste from oil and gas drilling is often disposed of through land application. These studies examined the agronomic and environmental impact of applying drilling mud to agricultural land. Specifically, we investigated the best methods for increasing TPH degradation from land applied oil-base drilling mud (OBM), and potential BTEX leaching, along with salt accumulation and leaching from water-base drilling mud (WBM) applied to wheat. This was achieved by conducting field and greenhouse leaching experiments. Mixing OBM with caliche, lime, or gypsum resulted in > 90% TPH degradation 60 days after application with no decrease in plant yield. BTEX leaching from surface applied OBM was minimal over 90 days and all BTEX leachate concentrations were below EPA drinking water thresholds. Increased surface applications of OBM resulted in decreased TPH degradation rates. Initial soil EC values were high after land applying WBM to wheat. Increased rainfall decreased soil EC levels by leaching salts out of the top 15 cm where the majority of roots occur for wheat. Depending on rainfall amounts, soil EC decreased below the saline threshold in 90-300 days. On average, it required 3 cm of rainfall to lower the soil EC by 1 mS cm-1 for the 0- 7.5 cm depth. Soil SAR values increased at each sampling day although never reaching the sodic threshold. Application of WBM had no impact on wheat yield except at the March application date. The land application of drilling mud may not have a long term agronomic and environmental impact if correctly applied. However, detrimental results to soil and plants can occur if over-applied. iii TABLE OF CONTENTS Chapter Page I. INTRODUCTION .................................................................................................. 1 LITERATURE REVIEW .................................................................................... 4 OBM Components ......................................................................................... 4 Rules/Regulations .......................................................................................... 4 Potential Hazards ........................................................................................... 5 Application and Degradation of OBM ............................................................ 7 WBM Components ...................................................................................... 11 Rules/Regulations ........................................................................................ 12 Potential Hazards ......................................................................................... 12 Application of WBM to Soils ....................................................................... 14 BTEX and Oil-Base Mud ............................................................................. 18 BTEX Degradation, Sorption, and Transportation ........................................ 18 References ......................................................................................................... 23 II. SURFACE APPLICATION OF OIL-BASE DRILLING MUD MIXED WITH GYPSUM, LIME, AND CALICHE ................................................................... 26 Abstract ............................................................................................................. 26 Introduction ....................................................................................................... 28 Materials and Methods ....................................................................................... 31 Site description and source of materials ........................................................ 31 Oil-base mud characterization ...................................................................... 31 Experiment setup and mud application ......................................................... 33 Soil analysis ................................................................................................. 34 Statistics ...................................................................................................... 34 Results and Discussion ...................................................................................... 36 Properties of the oil-base mud and background soil ...................................... 36 TPH degradation .......................................................................................... 37 Soil pH, soluble salts, and sodium absorption ratio ....................................... 40 Yield ............................................................................................................ 42 Conclusion ......................................................................................................... 43 References ......................................................................................................... 45 Tables and Figures ............................................................................................. 49 iv III. SURFACE APPLICATION OF WATER-BASE DRILLING MUD TO WINTER WHEAT .................................................................................................................. 55 Abstract ............................................................................................................. 55 Introduction ....................................................................................................... 57 Materials and Methods ....................................................................................... 60 Statistics ...................................................................................................... 61 Results and Discussion ...................................................................................... 62 Background soil properties ........................................................................... 62 Water-based mud properties ......................................................................... 62 Soil pH......................................................................................................... 63 Soil electrical conductivity ........................................................................... 63 Soil sodium adsorption ratio ......................................................................... 68 Wheat yield .................................................................................................. 70 Conclusion ......................................................................................................... 72 References ......................................................................................................... 74 Tables and Figures ............................................................................................. 76 v Chapter Page IV. TOTAL PETROLEUM HYDROCARBON DEGRADATION AND BTEX LEACHING IN SOILS AS A FUNCTION OF OIL-BASE DRILLING MUD APPLICATION RATE, RAINFALL REGIME, AND TIME ............................. 90 Abstract ............................................................................................................. 90 Introduction ....................................................................................................... 92 Materials and Methods ....................................................................................... 95 Statistics ...................................................................................................... 97 Results and Discussion ...................................................................................... 98 Background soil properties…………. .......................................................... 98 Oil-based mud properties ............................................................................. 98 OBM TPH ................................................................................................... 99 OBM BTEX ............................................................................................... 101 BTEX leachate concentrations ................................................................... 102 BTEX Loading........................................................................................... 104 Leachate EC ............................................................................................... 104 Leachate pH ............................................................................................... 105 Conclusion ....................................................................................................... 106 References ....................................................................................................... 108 Tables and Figures ........................................................................................... 111 V. SUMMARY ...................................................................................................