Making Frac Sand In Spec

Transcription

1 Making Frac Sand In Spec John Getty, MS, Instructor II and Lab Director Petroleum Engineering, Montana Tech 1

2 Topics for Discussion Where the money is How Frac Sand is Evaluated Testing for Exploration Testing for Production Published Standards 2

3 Shale gas provides the largest sources of growth in U.S. natural gas supply Figure 91. Natural gas production by source, (trillion cubic feet) From Energy Information Administration DOE/EIA-0383(2013) Annual Energy Outlook 2013, April

4 million barrels per day Lower 48 onshore tight oil development spurs increase in U.S. crude oil production Figure 96. Domestic crude oil production by source (million bpd) From DOE/EIA-0383(2013) Annual Energy Outlook 2013, April 2013, pg 81 4

5 million barrels per day Tight oil formations account for a significant portion of total U.S. production Figure 97. Total U.S. tight oil production by geologic formation, From DOE/EIA-0383(2013) Annual Energy Outlook 2013, April 2013, pg 82 5

6 North American Shale Gas and Frac Sand -Frac Sand Mine Shale gas graphic courtesy of Emily Cooper,

7 North America at Night 7

8 North America at Night Regina Bakken Minneapolis Billings Bismark 8

9 Proppant n. Particles used to prop open a fracture induced in an oil and gas reservoir via hydraulic fracturing treatment. US Silica 20/40 Ottawa White Saint-Gobain, 12/18 Interprop Intermediate Strength Ceramic 9

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11 Proppant Characteristics Natural Characteristics Things we can t control Particle roundness and sphericity Particle strength crush resistance Density Acid Solubility Processed Characteristics Things we can control Quality (amount of fines and impurities) Particle size (sieve distribution) 11

12 Required RP19C Protocols for Exploration, Production and Marketing Protocol Minerology (99% Silica) Sieve Analysis ( 6) (Not API Spec) Sphericity and Roundness ( 7) Acid Solubility ( 8) Turbidity ( 9) Densities (Bulk, App, Abs) ( 10) Crush-Resistance( 11) Loss on Ignition ( 12) (Resin coat only) E P M

13 Sampling and Sample Handling ISO (API RP19C) 4 and 5 Collection methods Frequency Bagging Splitting Record keeping (ISO thru 3; Scope, Normative References, Abbreviations) 13

14 Sample Segregation Very specific sampling protocol designed to ensure sample is representative Significant effects on results of Sieve analysis Crush results Cluster Count Sphericity and Roundness Can make in-spec material appear to be unacceptable (and visa versa) 14

15 Proppant Size Designation 20/

16 Sieve Analysis (Particle Size) ISO

17 Sieve Results Proppant weight 92 g API Size 20/40 Sieve Size Pan Original weight min test Grams in cut g returned Frequency (=n) 0.5% 2.5% 25.5% 19.8% 26.7% 22.1% 1.9% 0.9% % in range 94.1% 0.36% Error Mesh (um) Average size (=d) um n*d Mean Dia (um) Grams In Cut Freq= Grams Returned AveSize= PreviousSieve+This Sieve 2 Mean Diameter, d ave n d n 17

18 Sieve Distribution Line Graph 40 mesh mesh Data pairs consist of cut mid-point and frequency 18

19 Imaging Particle Size Analyzer Image from Retsch/Horiba Camsizer brochure (no endorsement implied) 19

20 One image (of 1,000s) PSA Results Frequency Plot Computes Sphericity and Roundness from the same images 20

21 Importance of Sieve Analysis Exploration covers a broad range of sizes (usually not API) Determines cut fractions (and economics) Characterizing each cut can be informative Production Regular schedule is a part of QC program Can detect process issues Sizing input can reveal changes in source material. Costly, but critical Commonly checked at the well head 21

22 Sphericity and Roundness ISO Examine 20 randomly selected particles Grade each particle on Roundness Grade each particle on Sphericity Find the arithmetic mean for each characteristic 22

23 Increasing Sphericity Proppant shape (from Krumbein/Schloss) Increasing Roundness 23

24 Micrograph of > 20 particles Photo: Rory Lapka, Montana Tech, 2011 Part# Spher Round Ave

25 Crush resistance ISO Sieve material to ensure desired cut Load the crush cell loose pack Ramp to desired stress, hold 2 minutes Sieve to determine fines produced 25

26 Determine K Value 5k sand 26

27 Percent Crush Effects of Handling on Crush Results Boxplot of Std, 2Min, Jarring, Bluv, Pluv 8 Data Std 2Min Jarring Bluv Pluv Handling Protocol (n=10) Bulau, C., Getty, J., The Effects of Handling on the Measured Crush Strength of Proppant, Undergraduate Research Project, Montana Tech, May 2013

28 Acid Solubility ISO Soak the proppant sample in a 12:3 mixture of Hydrochloric (HCl) and Hydroflouric (HF) acids, at 150 F for 30 minutes. Serves to confirm mineralogy Silica has very low solubility Everything else dissolves API standard is <2% /Crystallization/Filtration.htm 28

29 Turbidity (Fines and Impurities) ISO Determines the amount of suspended particles or other finely divided matter. 29

30 Bulk Density Density ISO How much can we get in a rail car? Apparent density Excludes extra-granular porosity Used to compute frac fluid densities Absolute density Grain density, or specific gravity, of the matrix Sand ρ=2.65g/cc Ceramic ρ=2.8g/cc 3.2g/cc Novel materials, goal: ρ=1.0g/cc (=ρ water ) 30

31 US Silica 20/40 Ottowa Presented here as an example only. Taken from a data sheet provided by US Silica, Jan Specs may not be current. 31

32 Conductivity Measurements ISO /API RP 19D Obtaining these measurements at StimLab earns an entry in their data base, which is used by a large number of O&G operators. accessed 2Jun13 32

33 Required RP19C Protocols for Exploration, Production and Marketing Protocol Minerology (99% Silica) Sieve Analysis ( 6) (Not API Spec) Sphericity and Roundness ( 7) Acid Solubility ( 8) Turbidity ( 9) Densities (Bulk, App, Abs) ( 10) Crush-Resistance( 11) Loss on Ignition ( 12) (Resin coat only) E P M

34 Making Frac Sand In Spec ISO (2006) plus Amendment 1 (2009) Protocol Spec Sieve Analysis ( 6) (btwn 1 st & 2 nd Primary) 90% Sphericity and Roundness ( 7) (sand) 0.6, 0.6 Acid Solubility ( 8) <2% Turbidity ( 9) Densities (Bulk, App, Abs) ( 10) Crush-Resistance( 11) (rec. for sand) Loss on Ignition ( 12) <250NTU No spec >2000psi No spec

35 Thank you. Questions? 35

36 Proppant Testing Labs Anderson Engineering 2417 W. Main St., Suite 1A Bozeman, MT (406) , Thomas Turf Services, Inc State Highway 30 College Station, TX , Proptester, Inc 7000 N. Broadway, Bldg 2, Suite 202 Denver, CO , Assured Testing Services 198 River Road Ridgway Pa , FracTAL 1217 Bandana Boulevard North St. Paul, Minnesota Stim-Lab (580) This list is provided as a courtesy and is not complete. No endorsement should be assumed. Neither John Getty nor Montana Tech have any financial interest in any of these companies. 36