Materials Comparison in Deep Well Acidizing Environments

Materials Comparison in Deep Well Acidizing Environments CSC 2011 Evan Hinshaw, P.E. & Dean Gambale www.tantaline.com 1 Background !   Acidizing is technique performed to sJmulate oil wells •  Typically mineral and organic acids are uJlized !   Corrosion damage even with inhibitors is expected at high temps. !   With H2S present, corrosion is accelerated www.tantaline.com 2 Industry Problem !   Deep well acidizing at high temperatures and pressures in the presence of H2S causes unacceptable rate of corrosion !   Materials have become the main barrier and challenge to reaching deep oil wells even with the use of strong inhibitors to prevent corrosion of these materials. www.tantaline.com 3 Industry Need !   To determine what materials are suitable for deep H2S containing well during acidizing condiJons where use of inhibitors are not feasible for these condiJons. www.tantaline.com 4 Experiment Honeywell Corrosion SoluJons was hired for the materials evaluaJon in sour gas condiJons Condi&on 1 Condi&on 2 !   8 Hour Exposure !   10% AceJc Acid !   450F (232C) www.tantaline.com ! 
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5 8 Hour Exposure 10% AceJc Acid 10% HCl 450F (232C) 15 psia H2S Materials Evaluated !   316L !   Ti 6-­‐4 !   Ti 6-­‐2-­‐4-­‐6 !   C276 !   Tantaline* * Tantaline is a tantalum surface alloy grown on 316 stainless steel www.tantaline.com 6 Equipment !   All experimental equipment was Tantaline treated • 
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Autoclave Valves Fi^ngs InstrumentaJon SJrrers www.tantaline.com 7 Results for CondiJon 1 !   8 Hour Exposure !   10% Ace&c Acid !   450F (232C) Material Avg. Weight Avg. Loss Corrosion Rate (mpy) 316L 38.2 242 Ti 6-­‐4 0.2 2.2 Ti 6-­‐2-­‐4-­‐6 None None C276 2.1 11.9 Tantaline None None !   TradiJonal materials are acceptable www.tantaline.com 8 Results for CondiJon 2 ! 
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8 Hour Exposure 10% Ace&c Acid 10% HCl 15 psia H2S Material Avg. Weight Avg. Loss (mg) Corrosion Rate (mpy) 316L 5.750 36,512 (Dissolved) Ti 6-­‐4 3.725 41,326 (Dissolved) Ti 6-­‐2-­‐4-­‐6 1.260 16,260 (Dissolved) C276 3.600 20,897 Tantaline None None !   TradiJonal materials are not acceptable www.tantaline.com 9 The Surface Alloying Procedure !   700-­‐900C: Gas phase process: •  Chemical Vapor DeposJon (T-­‐CVD) •  TaCl5 (gas) + H2 (g) -­‐> Ta (s) + HCl(g) !   Advantage compared to ”other coaJngs” •  Solid state diffusion (allow alloy bonding) •  Good penetraJon (surface treat I.D. & O.D.) •  The deposited tantaline is dense and ducJle Product
Sutability
control
Alkaline
cleaning
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Acidic
Pickling
www.tantaline.com Etching for
Tolerance
Control
Mounting of
parts
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Reactor
packing
Alloy
Bonding of
substrate &
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Deposion
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10 layer
Post
treatment
Polishing
& Grinding
100%
Quality
testing by
boiling in
hot HCl
Exit control
+
certificate
Tantaline = Pure Tantalum — All the chemical limitaJons of pure (100% dense) tantalum metal per ASTM B365 chemical composiJon only — All public corrosion data on Tantalum metal is relevant to Tantaline’s corrosion resistance www.tantaline.com 11 Surface Alloy The alloy zone formed is responsible for Tantaline’s rugged tantalum surface that will not chip or spall With a very tenacious Tantalum Oxide Layer. www.tantaline.com 12 K&'%&()'*"K*+?',(,8L"
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Ruggedness of Ta Surface Alloy !   Rockwell C indentaJons at bend apex •  Cone shaped Brale indenter with 150kgf !   Bent 180° over a ½” mandrel !   Subjected to 37% boiling HCl for 24 hours !   All samples passed and had no corrosion www.tantaline.com 14 1/,00";*+J,'0",I"O'6*'%&J,'0"
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Results -­‐ Equipment !   All Tantaline treated equipment showed no signs of corrosion. www.tantaline.com 16 Conclusions !   In deep oil well acidizing condiJons with H2S tradiJonal materials are insufficient !   Tantaline showed to be unaffected to the affects of strong acids at high temp. with H2S !   Strong potenJal for Tantaline treated Jtanium tubulars •  Lightweight substrate •  Corrosion resistance of tantalum metal www.tantaline.com 17 Conquer Corrosion
Thank You
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