THESIS PRODUCED WATER QUALITY CHARACTERIZATION AND PREDICTION FOR WATTENBERG FIELD Submitted by Huishu Li Department of Civil and Environmental Engineering In partial fulfillment of the requirements For the Degree of Master of Science Colorado State University Fort Collins, Colorado Spring 2013 Master’s Committee: Advisor: Kenneth H. Carlson Sybil Sharvelle John Stednick Copyright by Huishu Li 2013 All Rights Reserved ABSTRACT PRODUCED WATER QUALITY CHARACTERIZATION AND PREDICTION FOR WATTENBERG FIELD Produced water is the major Exploration &Production waste in oil and gas production operations on most onshore and offshore platforms. There are some concerns about the environmental impacts of produced water, because of the potential danger of large volume of water disposal by shale plays. Produced water is a complex mixture of dissolved and particulate inorganic and organic matters ranging from near freshwater quality to concentrated saline brine. The most abundant inorganic chemicals are calcium, magnesium, sodium and chloride. Other inorganic components, such as barium, strontium, boron, sulfate, carbonate and bicarbonate are also present in the produced water but at high concentrations. The dominant organic chemicals in most produced water are soluble low molecular weight organic acids and some aromatic hydrocarbons. Constituents of produced water vary a lot depending on a number of factors, including geographic locations, characteristics of formations (i.e. the depth of formation, porosity and permeability of formation rocks/sands, water content) and injected fracturing fluid. Since water is becoming a big issue in some arid areas and as regulations become more restrictive for disposal and reinjection, produced water reuse/recycle will be a solution to reduce the wastewater production and alleviate environmental effects. The main objective of this study was to statistically evaluate the produced water quality and to provide an assessment on the spatial distribution of specific groundwater quality parameters. Produced water samples were collected at 80 sample points (producing oil and gas wells) from May to August in 2012. pH, ii conductivity, alkalinity, turbidity, total organic carbon, total nitrogen, and barium were tested at Colorado State University’s Environmental Engineering lab; total dissolved solids (TDS), calcium, magnesium, sodium, potassium, strontium, boron, chloride and sulfate were measured in ACZ Laboratories Inc., Colorado. All the produced water samples were acidic with pH ranging from 5.1-6.8. TDS, cations, anions and organic carbons tested in our study varied a lot. Maps showing the spatial distributions of these parameters were made using ArcGIS. Linear correlations between chloride, conductivity/TDS, and cations (log) were shown, which made it possible to estimate unknown parameters. Spatial and temporal trends of pH, TDS and total organics together with inner relationships of ion concentrations could allow us to make predictions of produced water qualities. This project was the first phase of the development of a GIS application that will provide a tool that can benefit industry when making decisions regarding produced water recycling. Keywords: produced water, Wattenberg filed, water quality, spatial interpolation, GIS application iii ACKNOWLEDGEMENT First and foremost, I would like to acknowledge the support of my advisor, Dr. Kenneth H. Carlson for the valuable guidance and advice. He provided me this great opportunity getting involved in this project as an international student and inspired me greatly to work and study on my topic. His willingness to motivate me and my colleagues contributed to our projects. Deepest gratitude is also due to the members of the supervisory committee, Dr. Sybil Sharvelle and Dr. John Stednick rendered their help during the period of my project work. I also wish to express my gratitude to all the colleagues in our project team, Ashwin Dhanasekar, Bing Bai, Ildus Mingazetdinov, and Stephen Goodwin, without whose help this study would not have been successful. Special thanks to Mary Wedum who helped me with the academic writings. Last but not least I wish to avail myself of this opportunity, express a sense of gratitude and love to my friends and my beloved parents for their manual support, strength, help and for everything Place. iv TABLE OF CONTENTS Chapter 1 Introduction .................................................................................................................... 1 Chapter 2 Literature Review ........................................................................................................... 4 2.1 Unconventional natural oil and gas – Shale oil and gas development .................................. 4 2.2 Current drilling and fracturing technology............................................................................ 8 2.3 Produced Water ................................................................................................................... 10 2.3.1 Water Volume ............................................................................................................ 11 2.3.2 Water Quality ............................................................................................................. 13 2.4 Produced Water Impact ....................................................................................................... 24 2.5 Water Management ............................................................................................................. 25 2.6 Produced Water Treatment.................................................................................................. 30 2.7 Oil and gas production history in Wattenberg Field ........................................................... 33 2.8 Research Objectives ............................................................................................................ 36 Chapter 3 Methods and materials ................................................................................................. 38 3.1 Water Sampling ................................................................................................................... 38 3.2 Water sample analyses ........................................................................................................ 47 3.2.1 Water quality test parameters...................................................................................... 47 3.2.2 Water quality measurements ....................................................................................... 52 3.3 Produced water quality by U.S.G.S survey ......................................................................... 57 3.3.1 Produced water quality for the United States ............................................................. 57 v 3.3.2 Produced water quality for the state of Colorado ....................................................... 67 3.4 Spatial Interpolation ............................................................................................................ 69 3.4.1 Kriging ........................................................................................................................ 71 3.4.2 Thiessen polygons ....................................................................................................... 72 Chapter 4 Results and Discussions ............................................................................................... 73 4.1 Produced water characteristics in Wattenberg field ............................................................ 73 4.1.1 Chemical and physical characterization...................................................................... 73 4.1.2 Correlations of Ions..................................................................................................... 77 4.1.3 Water chemistry vs. formation geology ...................................................................... 94 4.1.4 Water quality temporal trend ...................................................................................... 96 4.2 Spatial distribution of major produced water qualities in Wattenberg field ....................... 99 Chapter 5 Conclusions ................................................................................................................ 108 References ................................................................................................................................... 109 Appendix Appendix 1 .............................................................................................................................. 115 Appendix 2 .............................................................................................................................. 119 Appendix 3 .............................................................................................................................. 120 Appendix 4 .............................................................................................................................. 121 Appendix 5 ............................................................................................................................. .122 vi LIST OF TABLES Table 2.1, Shale gas endowments of North America...................................................................... 6 Table 2.2, Shale gas resources within the United States................................................................. 7 Table 2.3, Reserves of shale oil worldwide ...................................................................................