Field Case Study #4 H2S Scavenging in Iron Bearing ... · Field Case Study #4 H 2 S Scavenging in...
Transcript of Field Case Study #4 H2S Scavenging in Iron Bearing ... · Field Case Study #4 H 2 S Scavenging in...
Field Case Study #4
H2S Scavenging in Iron Bearing
Substrates
Mike Singleton
Flow Assurance & Scale Team: Scale Workshop
Treetops Hotel, Aberdeen, 29 January 2019
Background
Project with Petronas
Full findings published at First EAGE/IFPEN
Conference on Sulphur Risk Management –
2018
Objective:
• Understand the mechanism of H2S scavenging by Fe
bearing substrates
• Generate scavenging capacities (mg/g) for inclusion
into reservoir models
Scavenging Capacity – Static Tests
Brine of known [H2S] (aq)
T = 25ºC or 96ºC
Substrate – mix of sand
and Siderite (FeCO3)
Samples taken over time
Assay for H2S(aq)
Correlate H2S removal to
Scavenging Capacity
(mg/g)
GAS
WATER
H2S
H2S(aq)
H+
HS-
S2-
OH-
Fe2+?
Sand + FeCO3(s)
CO2
CO2(aq)
HCO3-
CO32-
Scavenging Capacity – Static Tests
0
2
4
6
8
10
12
14
0 2 4 6 8 10 12 14
Sca
ve
ng
ing
ca
pa
city (
mg
/g)
Initial pH
Scavenging capacities for 2 g of siderite at 25°C and 96°CParticle size 100-315 µm unless otherwise stated
25 °C 96 °C
<100 µm shaken
<100 µm unshaken
<100 µm unshaken
Scavenging Capacity – Dynamic Tests
Fluid Inlet
Fraction
Collector
Inlet Pressure
Transducer
Differential
Pressure
Transducer
Outlet Pressure
Transducer
UVWater
bath
Column
Flow rate = 10 ml/h
Initial [H2S] = 250 ppm
Porosity of columns ≈ 40%
Mass of siderite = 4 g in 50 g (8
wt%)
Mass of crushed field core = 25 g
Injector
Transfer
vessel
maintains
[H2S]
Scavenging Capacity – Dynamic Tests
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0 10 20 30 40 50 60 70 80 90
Sc
ave
ng
ed
su
lph
ide
(m
g)
Cumulative volume (PV)
25 °C 4 g siderite 96 °C 4 g siderite
25 °C Crushed core 96 °C Crushed core
25°C
Crushed core = 144 mg total (5.76 mg/g)
Siderite pack = 51.72 mg total (1.03 mg/g)
96°C
Crushed core = 145 mg total (5.80 mg/g)
Siderite pack = 87 mg total (1.74 mg/g)
Scavenging Capacity – Dynamic Tests
0
5
10
15
20
1.2
0
1.6
1
2.1
7
2.9
2
3.9
2
5.2
7
7.0
8
9.5
2
12.8
17.2
23.1
31.1
41.8
56.2
75.6
102
137
184
247
332
446
600
%
High size (µm)
Particle size distribution (1.2 - 600 µm range)
Column Blank
0
5
10
15
0.1
0
0.1
4
0.1
9
0.2
6
0.3
6
0.4
9
0.6
8
0.9
3
1.2
8
1.7
5
2.4
1
3.3
2
4.5
6
6.2
7
8.6
2
11
.80
16
.30
22
.40
30
.80
42
.30
58
.20
80
.00
%
High size (µm)
Particle size distribution (0.1 - 80 µm range)
Column Blank
Column Blank
Mechanistic Interpretation
Grains of siderite (FeCO3)
Fe2+
Direction of flow
Fe2+ Fe2+ Fe2+ Fe2+ Fe2+
Fe2+
Mechanistic Interpretation
Grains of siderite (FeCO3)
Direction of flow
Fe2+ + FeS +
H2S
Fe2+ + S2- → FeS
Grain of (FeCO3) +
FeS
Fe2+
Mechanistic Interpretation
Grains of siderite (FeCO3)
Direction of flow
Fe2+ + FeS +
H2S
Fe2+ + S2- → FeS
Grains of (FeCO3) +
FeS