Current State of Oilfield Wastewater Reuse

Transcription

1 Current State of Oilfield Wastewater Reuse John Veil Workshop on Food- Energy- Water Nexus Issues in Energy Arlington, VA USA December 7 8, 2015

2 Topics for Discussion What is produced water? How much is generated in a year? How is it managed? Reuse op8ons Why are these op8ons not being used more o:en? 2

3 What is Produced Water? Water that comes to the surface with oil and gas Mostly natural groundwater Can also be water injected for water flooding or for hydraulic fracturing Flowback water vs. produced water Contains many chemical cons8tuents Salt content (salinity, total dissolved solids [TDS], electrical conduc8vity) Oil and grease Composite of many hydrocarbons and other organic materials Toxicity from various natural inorganic and organic compounds or chemical addi8ves NORM 3

4 Produced Water Data Sources For the past six years, this has been the best source of data Clark, C.E., and J.A. Veil, 2009, Produced Water Volumes and Management Prac3ces in the United States. The report contains detailed produced water volume data for 2007 ~21 billion bbl/year or 58 million bbl/day 882 billion gallons/year or 2.4 billion gallons/day hqp:// ANL_EVS R09_produced_water_volume_report_2437.pdf 4

5 Update to Detailed Produced Water Inventory for the U.S. The Ground Water Protec8on Council (GWPC) contracted with Veil Environmental to update the earlier report using 2012 as the baseline year. Data were collected during the second half of 2014 Report was published in April 2015 hqp:// 5

6 Approach Data were collected from state oil and gas agencies Agencies were asked to complete two tables showing oil, gas, and water produc8on volumes and water management prac8ces The example on the following slides uses Colorado data Addi8onal data were collected from some state environmental protec8on agencies and from several federal agencies (EPA, BLM, BOEM/BSSE All water coming to the surface from an oil or gas well, regardless of its origin, was counted as produced water Produced (forma8on) water Frac flowback water Water resul8ng from enhanced recovery opera8on Data and details were summarized for each state separately 6

7 Water Volume Table Colorado Data Type of Hydrocarbon # Wells Producing Primarily That Type of Hydrocarbon Total Volume of Produced Water Brought to Surface (bbl/ year) Volume of Hydrocarbon Produced (bbl/ year or Mmcf/ year) Crude oil from conven8onal 18, ,349,662 49,361,146 bbl/yr forma8ons Natural gas from conven8onal 32,000 1,104,038 Mmcf/yr forma8ons Crude oil from unconven8onal no data no data forma8ons Natural gas from no data 605,339 Mmcf/yr unconven8onal forma8ons (shale and CBM) Other flowback water from no data 27,039,785 no data hydraulically fractured wells Total 50, ,389,447 49,361,146 bbl/yr 1,709,377 Mmcf/yr 7

8 Water Management Table Colorado Data Management PracTce Total Volume of Produced Water Managed by That PracTce (bbl/year) Percentage of Produced Water Managed by That PracTce Injec8on for enhanced 123,854, % recovery Injec8on for disposal 123,889, % Surface discharge 40,315, % Evapora8on 35,002, % Offsite commercial disposal 22,392, % (pits) Beneficial reuse (recycled 47,648, % produced water and flowback used to make new frac fluids ) Total Volume Managed 393,102,659 8

9 Produced Water Volumes 9

10 Five Year Changes in Fluid Production Between 2007 and 2012 U.S. oil produc8on increased by 29% U.S. gas produc8on increased by 22% U.S. water produc8on increased by <1% 21.2 billion bbl vs. 21 billion bbl 10

11 Top Ten States in 2012 Water Production Ranking State 2012 Water (bbl/yr) % of Total Water 1 Texas 7,435,659, California 3,074,585, Oklahoma 2,325,153, Wyoming 2,178,065, Kansas 1,061,019, Louisiana 927,635, New Mexico 769,153, Alaska 624,762, Federal Offshore 358,389, Colorado 320,191,000 2

12 Ratio of Water to Oil Production Not all states provided separate water from oil produc8on and water from gas produc8on The weighted average water- to- oil (WOR) for 21 states is 9.2 bbl water/bbl oil. Two of the key water producing states (Texas and Oklahoma) were unable to dis8nguish the water generated from oil wells vs. water coming from gas wells. Both of those states have large numbers of older wells from mature fields that typically have very high WORs (much higher than the weighted average). It is very likely that if the wells from those states were averaged in, the na8onal weighted average WOR would be higher than 10 bbl/bbl. Crude Oil Water from Oil WOR (bbl/year) (bbl/year) State Alabama 11,310,000 37,858, Alaska 192,368, ,133, Arizona 51,900 66, Arkansas 6,567, ,614, California 197,749,000 3,071,362, Illinois 8,908, ,268, Indiana 2,350,000 48,931, Kansas 43,743, ,009, Michigan 7,400,000 25,000, Mississippi 24,146, ,069, Missouri 175,000 2,103, Montana 26,495, ,085, Nebraska 2,514,000 57,873, Nevada 368,000 5,865, New Mexico 85,341, ,902, New York 360, , North Dakota 243,272, ,426, Ohio 5,063,000 4,860, South Dakota 1,754,000 5,296, Virginia 9,700 54, Wyoming 45,382,000 1,646,601, Total Volume 905,327,200 8,291,584,100 Weighted Average WOR 9.2

13 Ratio of Water to Gas Production The weighted average water- to- gas ra8o (WGR) for 17 states is 97 bbl water/mmcf gas. The range of values from the different states was so large that using a WGR is not meaningful. Total Gas (Mmcf) Water from Gas (bbl/year) WGR State Alabama 216,000 68,761, Alaska 3,182,000 1,019, Arizona , Arkansas 1,137,000 10,253, California 174,000 3,222, Indiana 8,800 8,635, Kansas 299,000 90,010, Michigan 130,000 92,000, Mississippi 437,000 3,167, Montana 67,000 3,748, Nebraska 1, , New Mexico 1,252, ,028, New York 27, , North Dakota 259,000 6,721, Ohio 86, , Virginia 146,000 3,177, Wyoming 2,079, ,464, Total Volume 9,501, ,971,572 Weighted Average WGR 97

14 Why Did Oil and Gas Increase While Water Remained the Same? Here is my hypothesis: Conven8onal produc8on generates a small ini8al volume of water that gradually increases over 8me. The total life8me water produc8on from each well can be high Unconven8onal produc8on from shales and coal seams generates a large amount of flowback and produced water ini8ally but the volume drops off, leading to a low life8me water produc8on from each well Between 2007 and 2012, many new unconven8onal wells were placed into service and many old conven8onal wells (with high water cuts) were taken out of service The new wells generated more hydrocarbon for each unit of water than the older wells they replaced

15 Produced Water Management Practices 15

16 2012 Produced Water Management Practices Water management follows similar trends to the 2007 data Nearly all water from onshore wells is injected Nearly all water from offshore wells is treated and discharged InjecTon for Enhanced Recovery (bbl/yr) InjecTon for disposal (bbl/yr) Surface discharge (bbl/yr) EvaporaTon (bbl/yr) Offsite Commercial Disposal (bbl/yr) Beneficial Reuse (bbl/yr) Total Prod Water Managed (bbl/yr) 2012 Onshore Total 9,225,152,000 7,947,716, ,129, ,142,000 1,373,131, ,737,000 19,968,007,000 % Offshore Total 62,703,000 62,703, ,916, ,322,000 % U.S. Total 9,287,855,000 8,010,364,000 1,121,045, ,142,000 1,373,131, ,737,000 20,609,274,000 % Onshore Total 10,676,530,000 7,144,071, ,002,000 No data No data No data 17,959,603,000 % No data No data No data Offshore Total 48,673,000 1,298, ,381,000 No data No data No data 587,353,000 % No data No data No data U.S. Total 10,725,203,000 7,145,369, ,383,000 No data No data No data 18,546,955,000 % No data No data No data 100.0

17 Water Management other than Injection and Discharge The 2012 data provide more informa8on on other prac8ces Evapora8on is used in several western states Where offsite commercial disposal facili8es are available, some of the water is sent there. Most commercial facili8es use disposal wells Some use evapora8on ponds Beneficial reuse (other than reinjec8on for enhanced recovery opera8ons) is difficult to quan8fy Some states recycle their flowback water to make new drilling and frac fluids Some states allow spreading of produced water on unpaved roads for dust control and on other roads for deicing during winter weather There is limited reuse for irriga8on in a few states where the water already has low salinity or has been treated to low salinity

18 States Reporting Volumes for Produced Water Reuse State AR CA CO OH PA PW Reuse Volume (bbl/yr) How It Is Reused 2,000,000 Reused to make up new frac fluids 46,251,000 Not specified by the State. But there are some examples in the literature. In the San Ardo field some of the pw is treated and reused for cooling tower makeup water. The remaining water undergoes further treatment to create water suitable to recharge a shallow aquifer that was used in the area for crop irriga8on. Up to 50,000 barrels/day of brackish pw was transformed into freshwater for agricultural reuse, which was enough to irrigate about 800 acres of farmland per year. 47,648,000 Reused to make up new frac fluids 756, ,575 bbl were used for deicing and dust control on roads, and 626,208 bbl were recycled to make new drilling fluids and frac fluids. 29,082,000 Reused to make up new frac and drilling fluids Several other states reported that they believed produced water was reused, but were uncertain about the volume and/or how it was actually used: KS, MI, NY, TX, UT, WV, WY

19 Ways in Which Produced Water Can Be Reused 19

20 Options for Reuse of Produced Water Reuse in the oil and gas fields Produce more oil Use for drilling fluids and frac fluids Industrial use Roadway use Injec8on for future use Injec8on for hydrological purposes Agricultural use Drinking water and other domes8c uses Secondary use

21 Reuse for Producing More Oil Nearly half of all U.S. produced water is separated from the oil and gas at the surface and then reinjected back into an oil- bearing forma8on to help produce more oil This can be done using water (water flooding) or steam (steam flooding) SAGD and other steam processes are common in Canada Although this prac8ce is not always viewed as beneficial reuse, it provides a valuable service to the industry and avoids injec8on of millions of barrels of surface and ground water to accomplish the same enhanced recovery ac8vi8es I believe it is truly beneficial reuse and should be given credit as such

22 In some parts of the country, a very large percentage of flowback water and produced water are given simple filtra8on or other treatment and then are reused to make up new drilling fluids and frac fluids Data in the table show management prac8ces in the Pennsylvania por8on of the Marcellus Shale during % of flowback 78% of prod water Other Reuse in the Oil and Gas Fields Centralized treatment for reuse InjecTon - disposal Residual waste processing and reuse Reuse other than roadspreading Storage waitng for disposal or reuse Flowback Prod Water Total % 1,398,438 2,131,496 3,529, ,679 3,493,527 3,564, , , , ,149,339 11,418,150 19,567, , , , Landfill 6, ,644 <0.1 Discharge <0.1 Roadspread <0.1 Total 9,719,945 17,406,287 27,126,

23 Industrial Use Cooling water makeup Vehicle washwater Process water Other

24 Roadway Use Dust control on unpaved roads Snow and ice control during winter storms Road stabiliza8on

25 Injection for Future Use Aquifer storage and recovery Inject treated produced water into shallow aquifer Withdraw it later as a water supply Example in Wellington, CO

26 Injection for Hydrological Purposes Subsidence control Salt water intrusion Flow augmenta8on

27 Agricultural Use Irriga8on Livestock and wildlife watering Managed wetlands Reed beds in Oman Source: USDA Source: USFWS Source: USFWS

28 Drinking Water and Other Domestic Uses

29 Secondary Use Geothermal power Feedstock for obtaining uncommon minerals and chemicals Lithium Rare earth metals Source: DOE Rocky Mountain Tes8ng Center

30 A New Application For Reusing Frac Byproducts Discovered in a grocery store in Bolivia in 2013

31 Why is Produced Water Not Reused More? 31

32 Knowledge Gaps (Barriers) and Research to Overcome Them Economic Salt removal is very expensive and is o:en necessary prior to reuse Water is heavy and expensive to move long distances Research Social Develop databases or clearinghouses to match up water sellers and poten8al buyers This is being done already by Sourcewater Inc. Some poten8al end users may not want to use produced water for agricultural applica8ons The public may have concerns over trea8ng produced water and reusing it for drinking water Research 32

33 Knowledge Gaps (Barriers) and Research to Overcome Them Economic Salt removal is very expensive and is o:en necessary prior to reuse Water is heavy and expensive to move long distances Research Develop databases or clearinghouses to match up water sellers and poten8al buyers This is being done already by Sourcewater Inc. Social Some poten8al end users may not want to use produced water for agricultural applica8ons The public may have concerns over trea8ng produced water and reusing it for drinking water Research Develop and publish case examples to help educate poten8al consumers 33

34 Knowledge Gaps (Barriers) and Research to Overcome Them Policy Water rights as long as produced water is a waste, water rights owner is not too concerned. But if produced water can be sold, water rights owner wants a cut of the fee. Liability Large oil and gas companies are worried about the risk of later lawsuits if produced water is sold or given to end users Research Try to educate lawmakers and staffers Look to establish third- party en88es that can accept produced water and distribute it to end user (mi8gates liability) 34