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©	2015		
Chemistry	Ma2ers	Inc. 1	GeoConven)on	2016	–	www.chemistry-ma:ers.com	
Making	chemistry	data	meaningful	
Character...
©	2015		
Chemistry	Ma2ers	Inc.
Acknowledgements	
2	
•  Sco:	Mundle,	PhD,	C.Chem,	P.Chem	
	
	
GeoConven)on	2016	–	www.chemi...
©	2015		
Chemistry	Ma2ers	Inc.
Surface	Casing	Vent	Flows	and	Geoforensics	
3	GeoConven)on	2016	–	www.chemistry-ma:ers.com
©	2015		
Chemistry	Ma2ers	Inc.
Geoforensics	
4	GeoConven)on	2016	–	www.chemistry-ma:ers.com	
Introducing a new term: Geofo...
©	2015		
Chemistry	Ma2ers	Inc.
Surface	Casing	Vent	Flows	(SCVFs)	
5	GeoConven)on	2016	–	www.chemistry-ma:ers.com	
SCVFs co...
©	2015		
Chemistry	Ma2ers	Inc.
What	do	SCVFs	look	like?	
6	GeoConven)on	2016	–	www.chemistry-ma:ers.com	
Steam
Oily Bubble...
©	2015		
Chemistry	Ma2ers	Inc.
o  Surface casing used to protect
shallow (potable) aquifers
o  Fluids(gas and/or liquid)
m...
©	2015		
Chemistry	Ma2ers	Inc.
o  Geochemical characterization of sources to identify ‘fugitive’
gas migration in the oil/...
©	2015		
Chemistry	Ma2ers	Inc.
Geochemical	characterizaJons	&	forensics	
o  Gases/fluids for different
zones can be
‘finge...
©	2015		
Chemistry	Ma2ers	Inc.
The	geochemistry	is	never	wrong,	but	the	
interpretaJon	is	oPen	incorrect	
o  Common proble...
©	2015		
Chemistry	Ma2ers	Inc.
Don’t	make	assumpJons	based	on	regional	
geochemistry	
o  Where do the ‘fingerprints’
origi...
©	2015		
Chemistry	Ma2ers	Inc.
Sampling	and	Data	AcquisiJon	–	Step	1	
12	GeoConven)on	2016	–	www.chemistry-ma:ers.com
©	2015		
Chemistry	Ma2ers	Inc.
Need high quality SCV samples
o  Can separate and collect gas, liquid and
steam
o  AER is c...
©	2015		
Chemistry	Ma2ers	Inc.
Sample	media	can	affect	‘fingerprints’	
•  Over time isotopic composition of methane and CO2 ...
©	2015		
Chemistry	Ma2ers	Inc.
Goal	for	Gas	Sampling	
•  Maximize	gas	concentra)on	
–  Least	amount	of	air	as	possible	
– ...
©	2015		
Chemistry	Ma2ers	Inc.
Liquids	Sampling	
•  Slow/low	volume	liquid	vent	flows	
problema)c	sampling	
•  Requires	pas...
©	2015		
Chemistry	Ma2ers	Inc.
Best	PracJces	Required	for	SCVF	Sampling	
•  Ban	the	term	“Grab	a	sample”	
	
•  Sampling	ga...
©	2015		
Chemistry	Ma2ers	Inc.
IdenJficaJon	and	CharacterizaJon	of	
Source	Zones	
18	GeoConven)on	2016	–	www.chemistry-ma:e...
©	2015		
Chemistry	Ma2ers	Inc.
How	can	you	get	it	right	every	Jme?	
Mudgas Geochemical Profile
Characterized stratigraphy
...
©	2015		
Chemistry	Ma2ers	Inc.
Case	Studies	–	Using	End-Members	to	
IdenJfy	SCVFs	
20	GeoConven)on	2016	–	www.chemistry-ma...
©	2015		
Chemistry	Ma2ers	Inc.
Case	Study	
•  Collected	four	samples	from	each	loca)on:	
–  SCV	gas	sample	
–  SCV	liquid	...
©	2015		
Chemistry	Ma2ers	Inc.
Conservative Chemistry
o  Characterization of SCV fluids focused on both routine and
‘conse...
©	2015		
Chemistry	Ma2ers	Inc.
SCVF Analysis
o  Specific conservative isotopes and their analyte
concentrations were disco...
©	2015		
Chemistry	Ma2ers	Inc.
SCVF – Example 1
Conclusion:
o  SCV leak is from production zone
o  Gas is entirely product...
©	2015		
Chemistry	Ma2ers	Inc.
SCVF – Example 2
o  Gas/liquid origin not from production zone
o  Based on MGIL, 300-400 m ...
©	2015		
Chemistry	Ma2ers	Inc.
Best Practices for SCVF Sampling
•  Collect	high	quality	samples	–	protected	from	
degrada)...
©	2015		
Chemistry	Ma2ers	Inc.
Best Practices for Identifying SCVF
•  Proper	sampling	and	characteriza)on	of	poten)al	
sou...
©	2015		
Chemistry	Ma2ers	Inc.
Thank you for your attention
Contact Info:
Chemistry Matters Inc.
Court Sandau
Cell: 403.66...
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GeoConvention2016_Identifying Surface Casing Vent Flows (SCVF) Using Geoforensics

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Presentation at 2016 GeoConvention in Calgary, Alberta. Presentation covered best practices for the collection of samples then using advanced geochemistry and geoforensics to identify source zones of SCVFs.

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GeoConvention2016_Identifying Surface Casing Vent Flows (SCVF) Using Geoforensics

  1. 1. © 2015 Chemistry Ma2ers Inc. 1 GeoConven)on 2016 – www.chemistry-ma:ers.com Making chemistry data meaningful Characterizing the source zones for surface casing vent leaks Court D. Sandau, PhD, P.Chem March 8, 2016 – GeoConvenCon 2016, Calgary, AB
  2. 2. © 2015 Chemistry Ma2ers Inc. Acknowledgements 2 •  Sco: Mundle, PhD, C.Chem, P.Chem GeoConven)on 2016 – www.chemistry-ma:ers.com •  Live tweets: #GeoCon2016 and #GeoForensics
  3. 3. © 2015 Chemistry Ma2ers Inc. Surface Casing Vent Flows and Geoforensics 3 GeoConven)on 2016 – www.chemistry-ma:ers.com
  4. 4. © 2015 Chemistry Ma2ers Inc. Geoforensics 4 GeoConven)on 2016 – www.chemistry-ma:ers.com Introducing a new term: Geoforensics •  Forensics is derived from latin “forens”, meaning of, belonging to the forum, public •  Geoforensics is the application of scientific methods used to identify source(s) of chemical constituents (natural or man made) in fluids (gases, groundwater, oil), soil and/or rock from the subsurface of the Earth for use in potential litigious issues or for public debate or discussion.
  5. 5. © 2015 Chemistry Ma2ers Inc. Surface Casing Vent Flows (SCVFs) 5 GeoConven)on 2016 – www.chemistry-ma:ers.com SCVFs come in many shapes and sizes -  High pressure and intensity are generally easy to identify (e.g. EOR fields) -  Low flows/pressures provide difficult sampling opportunities (Houdini wells – “no you see them, now you don’t” -  L.F. 2012 – “Flow’ers and Show’ers”
  6. 6. © 2015 Chemistry Ma2ers Inc. What do SCVFs look like? 6 GeoConven)on 2016 – www.chemistry-ma:ers.com Steam Oily Bubbles Intermittent Flow Constant Fizz
  7. 7. © 2015 Chemistry Ma2ers Inc. o  Surface casing used to protect shallow (potable) aquifers o  Fluids(gas and/or liquid) migrate from deeper zones through SCV o  Gas migration occurs outside the SCV o  Irregular and low flow rates (can be difficult to sample/ monitor) o  How can you determine the source(s) of the leaks? Surface casing vent flow and gas migration GeoConven)on 2016 – www.chemistry-ma:ers.com 7
  8. 8. © 2015 Chemistry Ma2ers Inc. o  Geochemical characterization of sources to identify ‘fugitive’ gas migration in the oil/gas sector Geochemical ‘fingerprinting’ GeoConven)on 2016 – www.chemistry-ma:ers.com 8
  9. 9. © 2015 Chemistry Ma2ers Inc. Geochemical characterizaJons & forensics o  Gases/fluids for different zones can be ‘fingerprinted’ o  But why does this approach sometimes fail? GeoConven)on 2016 – www.chemistry-ma:ers.com 9
  10. 10. © 2015 Chemistry Ma2ers Inc. The geochemistry is never wrong, but the interpretaJon is oPen incorrect o  Common problems: o  Sample degraded prior to analysis o  Either the wrong ‘end- members’, or no ‘end- members are used to identify sources o  Misinterpretation of the data (e.g. not noticing altered fingerprints, or using wrong data) GeoConven)on 2016 – www.chemistry-ma:ers.com 10
  11. 11. © 2015 Chemistry Ma2ers Inc. Don’t make assumpJons based on regional geochemistry o  Where do the ‘fingerprints’ originate? o  Commercial isotope “databases” often use regional values rather than local values that can mislead interpretations GeoConven)on 2016 – www.chemistry-ma:ers.com 11
  12. 12. © 2015 Chemistry Ma2ers Inc. Sampling and Data AcquisiJon – Step 1 12 GeoConven)on 2016 – www.chemistry-ma:ers.com
  13. 13. © 2015 Chemistry Ma2ers Inc. Need high quality SCV samples o  Can separate and collect gas, liquid and steam o  AER is considering requirement for monitoring SCV flow in SAGD wells, what about steam? o  Need low atmospheric content in gas samples for compositional and isotopic characterization Steam GeoConven)on 2016 – www.chemistry-ma:ers.com 13
  14. 14. © 2015 Chemistry Ma2ers Inc. Sample media can affect ‘fingerprints’ •  Over time isotopic composition of methane and CO2 changes •  Methane artificially appears more ‘thermogenic’ •  Shift in CO2 is not predictable •  Manufacturer recommendations = analyze in 48 hours GeoConven)on 2016 – www.chemistry-ma:ers.com 14
  15. 15. © 2015 Chemistry Ma2ers Inc. Goal for Gas Sampling •  Maximize gas concentra)on –  Least amount of air as possible –  Purge air from “system”, allow gas to accumulate if necessary •  Eliminate moisture –  Break out water or steam •  Preserve sample to prevent degrada)on •  Analyze sample within hold )me –  48 hours for bags 15 GeoConven)on 2016 – www.chemistry-ma:ers.com
  16. 16. © 2015 Chemistry Ma2ers Inc. Liquids Sampling •  Slow/low volume liquid vent flows problema)c sampling •  Requires passive sampling to preserve chemistry of the liquid 16 GeoConven)on 2016 – www.chemistry-ma:ers.com 0.0001$ 0.001$ 0.01$ 0.1$ 1$ 10$ 100$ 1000$ 10000$ 100000$ Lithium$ Sodium$ Potassium$ Rubidium$ Cesium$ Beryllium$ Magnesium$ Calcium$ Stron=um$ Barium$ Boron$ Aluminum$ Gallium$ Indium$ Thallium$ Silicon$ Germanium$ Tin$ Lead$ Phosphorus$ Arsenic$ An=mony$ Bismuth$ Sulphur$ Selenium$ Tellurium$ Chlorine$ Bromine$ Iodine$ Scandium$ YDrium$ Titanium$ Zirconium$ Vanadium$ Niobium$ Tantalum$ Chromium$ Molybdenum$ Tungsten$ Manganese$ Iron$ Cobalt$ Nickel$ Palladium$ Pla=num$ Copper$ Silver$ Gold$ Zinc$ Cadmium$ Mercury$ Lanthanum$ Cerium$ Praseodymium$ Neodymium$ Samarium$ Europium$ Gadolinium$ Terbium$ Dysprosium$ Holmium$ Erbium$ YDerbium$ Thorium$ Uranium$ BleedNbarrel$ FlowNthrough$Cell$ 1 2 3 4 5 6 7 d-block f-block
  17. 17. © 2015 Chemistry Ma2ers Inc. Best PracJces Required for SCVF Sampling •  Ban the term “Grab a sample” •  Sampling gases is sampling the invisible –  Need good connec)ons/seals –  Leak tests (check connec)ons) –  Ensure sample integrity maintained •  Sampling liquids –  Easier to sample, some)mes harder to collect –  Passive collec)on systems, but protected from environmental degrada)on •  Higher quality data = Higher chance for success! 17 GeoConven)on 2016 – www.chemistry-ma:ers.com
  18. 18. © 2015 Chemistry Ma2ers Inc. IdenJficaJon and CharacterizaJon of Source Zones 18 GeoConven)on 2016 – www.chemistry-ma:ers.com
  19. 19. © 2015 Chemistry Ma2ers Inc. How can you get it right every Jme? Mudgas Geochemical Profile Characterized stratigraphy Prod./Source Zones: 1.) Fluids 2.) Gases Characterized end-members Shallow Fluids 1.) Surface water 2.) Groundwater Characterized inputs SCVs: Identify matrix 1.) Fluid 2.) Gas GEOCHEMISTRY: 19 19 GeoConven)on 2016 – www.chemistry-ma:ers.com
  20. 20. © 2015 Chemistry Ma2ers Inc. Case Studies – Using End-Members to IdenJfy SCVFs 20 GeoConven)on 2016 – www.chemistry-ma:ers.com
  21. 21. © 2015 Chemistry Ma2ers Inc. Case Study •  Collected four samples from each loca)on: –  SCV gas sample –  SCV liquid sample –  Produc)on casing gas sample –  Produc)on casing liquid sample •  Used local groundwater and deep aquifer wells in region for comparison •  Targeted source zones (end-members) were sampled and characterized •  Full MGIL for region 21 GeoConven)on 2016 – www.chemistry-ma:ers.com
  22. 22. © 2015 Chemistry Ma2ers Inc. Conservative Chemistry o  Characterization of SCV fluids focused on both routine and ‘conservative’ analytes: •  pH, alkalinity •  Concentrations of dissolved cations and anions •  Extended metals (65 in total) •  Stable isotopes (18O, 2H, 11B, 13C, 34S, 37Cl, 81Br, 87/86Sr) •  Conservative isotopes were required for the following cases to elucidate fluid source due to pH alteration of all susceptible analytes 22 GeoConven)on 2016 – www.chemistry-ma:ers.com
  23. 23. © 2015 Chemistry Ma2ers Inc. SCVF Analysis o  Specific conservative isotopes and their analyte concentrations were discovered to be characteristic of specific formations. 23 GeoConven)on 2016 – www.chemistry-ma:ers.com
  24. 24. © 2015 Chemistry Ma2ers Inc. SCVF – Example 1 Conclusion: o  SCV leak is from production zone o  Gas is entirely production formation o  Water is production zone mixed with intermediate GW C1 C2 C3 CO2 SCV -51.9 -45.4 -35.9 bdl Casing gas -50.0 -43.1 -35.9 -2.5 Isotopevalue Concentration value Gas Results Liquid Results 24 GeoConven)on 2016 – www.chemistry-ma:ers.com Mississippian Cretaceous Mississippian Cretaceous
  25. 25. © 2015 Chemistry Ma2ers Inc. SCVF – Example 2 o  Gas/liquid origin not from production zone o  Based on MGIL, 300-400 m origin Conclusion: o  SCV leak is from shallow zone C1 C2 C3 CO2 SCV -61.7 -48.0 bdl bdl Casing gas -48.6 -39.9 -36.6 -18.8 Isotopevalue Concentration value Gas Results Liquid Results 25 GeoConven)on 2016 – www.chemistry-ma:ers.com Mississippian Cretaceous Mississippian Cretaceous
  26. 26. © 2015 Chemistry Ma2ers Inc. Best Practices for SCVF Sampling •  Collect high quality samples – protected from degrada)on, purge gas prior to sampling, etc. •  Preserve samples in the field •  Collect poten)al source samples and from the produc)on casing (if possible) •  Use basic chemistry but if not useful, may need conserva)ve analytes •  Conserva)ve analytes can provide clarity for difficult SCV fluid samples 26 GeoConven)on 2016 – www.chemistry-ma:ers.com
  27. 27. © 2015 Chemistry Ma2ers Inc. Best Practices for Identifying SCVF •  Proper sampling and characteriza)on of poten)al source zones (gas and liquids) •  Solid MGIL for the area •  Good database for the area of successful interven)ons •  Geochemistry data is always telling you something, interpre)ng the message is key! 27 GeoConven)on 2016 – www.chemistry-ma:ers.com
  28. 28. © 2015 Chemistry Ma2ers Inc. Thank you for your attention Contact Info: Chemistry Matters Inc. Court Sandau Cell: 403.669.8566 Email: csandau@chemistry-matters.com URL: chemistry-matters.com Visit my website and sign up for email for automatic receipt of my blogs! Twitter: @Chem_Matters Slideshare: www.slideshare.net/csandau 28 GeoConven)on 2016 – www.chemistry-ma:ers.com

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