Advanced Natural Gas Engineering

417 Pages·2010·3.54 MB·English

Advanced Natural Gas Engineering
Xiuli Wang
XGAS
Michael Economides
University of Houston
Gulf Publishing Company
Houston, Texas
Advanced Natural Gas Engineering
Copyright © 2009 by Gulf Publishing Company, Houston, Texas. All rights
reserved. No part of this publication may be reproduced or transmitted in any
form without the prior written permission of the publisher.
Gulf Publishing Company
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Library of Congress Cataloging-in-Publication Data forthcoming
Printed in the United States of America
∞
Printed on acid-free paper.
Editing, design and composition by TIPS Technical Publishing, Inc
List of Figures
Figure 1–1 Artist’s rendition of onshore petroleum reservoir...2
Figure 1–2 Artist’s rendition of offshore petroleum reservoir...3
Figure 1–3 Sedimentary environment.......................................4
Figure 1–4 Grain sizes of sediments..........................................5
Figure 1–5 Natural gas reservoirs and trapping mechanisms ...7
Figure 1–6 Gas cap.....................................................................7
Figure 1–7 Phase diagram........................................................10
Figure 1–8 The gas deviation factor for natural gases.............15
Figure 1–9 Pseudocritical properties of natural gases..............17
Figure 1–10 Pseudocritical temperature adjustment factor, e ..21
3
Figure 1–11 Viscosity of natural gases at 1 atm.........................26
Figure 1–12 Viscosity ratio at elevated pressures and
temperatures..........................................................26
Figure 1–13 Viscosity of gases at 1 atm.....................................27
Figure 2–1 Offshore seismic data acquisition..........................37
Figure 2–2 S-wave impedance from AVO inversion for an
offshore natural gas bearing structure...................39
Figure 2–3 Calculated Poisson ratios for the zone of interest
in Figure2–2...........................................................39
Figure 2–4 Seismic attribute of a structure: Ratios of
compressional-reflection to shear-reflection
amplitudes..............................................................40
Figure 2–5 Drilling rig components........................................42
xix
xx List of Figures
Figure 2–6 Measured versus extrapolated from correlations
drilling fluid densities at high pressures................46
Figure 2–7 Measured drilling fluid densities of four fluids
at depth and at predicted temperatures and
pressures.................................................................46
Figure 2–8a Onshore wellbore example....................................50
Figure 2–8b Offshore wellbore example....................................51
Figure 2–9 Selected completion types.....................................51
Figure 2–10 Gas critical flow rate versus flowing tubing
pressure for Example2–5.......................................55
Figure 3–1 Steady-state flow....................................................63
Figure 3–2 Production versus flowing bottomhole pressure
for Example3–1........................................................67
Figure 3–3 A sketch of an openhole vertical well and its
cross section...........................................................75
Figure 3–4 Turbulence effects in both horizontal and
vertical wells...........................................................81
Figure 3–5 Effects of index of permeability anisotropy..........82
Figure 3–6 Pushing the limits: maximum J with constraints...88
D
Figure 3–7 Folds of increase between fractured and
unfractured wells...................................................94
Figure 3–8 Fluid flow from reservoir to a transverse fracture....95
Figure 3–9 Chart of iterative calculation procedure................97
Figure 3–10 Productivity comparison among vertical and
horizontal wells with and without fracture...........98
Figure 3–11 Skin versus permeability in the single transversely
fractured horizontal well.......................................99
Figure 3–12 Flow geometry in pipe.........................................100
Figure 3–13 Well deliverability for Example3–9, k =1 md,
D = 3 in..............................................................105
tbg
Figure 3–14 Well deliverability for Example3–9, k =10 md,
D = 3 in..............................................................105
tbg
Figure 3–15 Well deliverability for Example3–9, k =10 md,
D =6.3in..............................................................106
tbg
Figure 3–16 Material balance for Example3–10.....................108
Figure 3–17 Production rate, reservoir pressure, and
cumulative recovery for Example3–10...............109
List of Figures xxi
Figure 4–1 Generalized gas processing schematic.................117
Figure 4–2 Forces on liquid droplet.......................................119
Figure 4–3 Vertical three-phase separator.............................124
Figure 4–4 Obtain G from the downcomer allowable flow...128
Figure 4–5 Two-phase vertical separator...............................135
Figure 4–6 Three-phase horizontal separator..............................140
Figure 4–7 Three-phase horizontal separator with a weir.....146
Figure 4–8 Water content of sweet natural gas.....................153
Figure 4–9 Water content correction for sour natural gas....155
Figure 4–10 Hydrate formation prediction.............................158
Figure 4–11 A sketch of a typical glycol dehydration process 161
Figure 4–12 Gas capacity for packed glycol gas absorbers
forg = 0.7 at 100°F..............................................161
g
Figure 4–13 Trays or packing required for glycol dehydrators...163
Figure 5–1 Economically preferred options for monetizing
stranded natural gas.............................................173
Figure 5–2 Basic pipeline capacity design concept................173
Figure 5–3 Diagram for Example5–1....................................176
Figure 5–4 Moody diagram....................................................178
Figure 5–5 Pipeline and compressor station for Example5–2...179
Figure 5–6 Work needed to compress gas from p to p ........181
1 2
Figure 5–7 Loading and offloading terminal for LNG
and CNG..............................................................186
Figure 5–8 Regions actively investigating CNG projects.......187
Figure 5–9 Schematic of a CNG vessel...................................189
Figure 5–10 Schematic of a CNG vessel...................................190
Figure 5–11 Gas deviation factor Z as function of pressure
and temperature for natural gas..........................190
Figure 5–12 Value of ZT/p as function of pressure and
temperature for natural gas.................................191
Figure 5–13 “Hub-and-Spoke” (left) and “Milk-Run” (right)
paths for CNG distribution to N receiving sites
(terminals T ,…,T ).............................................193
1 N
Figure 5–14 Potential “Hub-and-Spoke” scheme for CNG
distribution to island countries in the Caribbean
Sea with large consumption of electricity...........194
xxii List of Figures
Figure 5–15 Potential “Milk-Run” scheme for CNG
distribution to island countries in the Caribbean
Sea with small consumption of electricity..........195
Figure 5–16 Scheduling of gas delivery from a single source
to a single delivery site using two CNG vessels...195
Figure 5–17 Scheduling of gas delivery from a single source
to a single delivery point using three CNG vessels..195
Figure 5–18 Scheduling of gas delivery from a single source
to a single delivery site using n CNG vessels.......196
Figure 5–19 Minimum number of vessels, n , required
min
to implement a CNG delivery schedule
corresponding to various ratios of
consumptions rates over loading rates................197
Figure 5–20 Dependence of vessel capacity and total fleet
capacity on the number of vessels, n, for
Example5–4.........................................................200
Figure 5–21 Dependence of vessel capacity and total fleet
capacity on the number of vessels, n, for
Example5–5.........................................................203
Figure 5–22 Schedule development for CNG distribution by
n similar vessels to N receiving sites serviced
successively on a cyclical path as shown in
Figure5–13...........................................................204
Figure 5–23 Destinations for CNG delivery using Milk-Run
scheme.................................................................207
Figure 6–1 Typical LNG plant block flow diagram................211
Figure 6–2 Typical natural gas/refrigerant cooling curves....213
Figure 6–3 Simple cooler/condenser......................................216
Figure 6–4 Three-stage process for liquefaction....................218
Figure 6–5 Simple flash condensation process......................220
Figure 6–6 Simplified schematic of Linde process.................221
Figure 6–7 APCI process.........................................................223
Figure 6–8 p-H diagram for methane....................................224
Figure 6–9 Simplified APCI process schematic......................225
Figure 6–10 Typical propane precooled mixed refrigerant
process..................................................................228
Figure 6–11 Optimized cascade process..................................229
Figure 6–12 Single mixed refrigerant loop..............................230
List of Figures xxiii
Figure 6–13 Mixed fluid cascade process (MFCP)......................232
Figure 6–14 IFP/Axens Liquefin™ process.................................233
Figure 6–15 Schematic overview of the DMR refrigeration
cycles....................................................................235
Figure 6–16 LNG carrier size progression................................236
Figure 6–17 Moss type LNG tanker.........................................237
Figure 6–18 Membrane type LNG tanker................................237
Figure 7–1 Basic flowchart of indirect conversion of
natural gas to liquids through syngas and
Fischer-Tropsch synthesis....................................246
Figure 7–2 Relative values of equilibrium constants for
steam reforming and water gas shift
Reactions (7.14) and (7.15), respectively.............253
Figure 7–3 Equilibrium compositions for steam reforming
at 20atm and stoichiometry H O/CH = 3.
2 4
Methane converson is complete at about
1,000°C. The production of CO from the water
2
gas shift reaction is maximum around 700°C....253
Figure 7–4 The ratio of H /CO as a function of the ratio of
2
steam/methane for Example7–3.........................257
Figure 7–5 Relative activity of transition metal catalysts for
steam reforming..........................................................257
Figure 7–6 Configuration of a steam reforming reactor at
multiple levels of detail: (a) tube bundle in
furnace, (b) reactor tube, and (c) catalyst pellet.
Heat can be provided to the long tubes in a
number of ways, not shown................................259
Figure 7–7 Autothermal reforming reactor...........................261
Figure 7–8 Configuration of ceramic membrane partial
oxidation reactor (not drawn to scale)................263
Figure 7–9 Timeline of Fischer-Tropsch synthesis................264
Figure 7–10 Thermodynamics of the Fischer-Tropsch
synthesis of decane (n = 10) via the reaction
10CO + 20H → C H + 10H O..........................267
2 10 20 2
Figure 7–11 Initiation step of Fischer-Tropsch reactions........269
Figure 7–12 Chain growth step of Fischer-Tropsch reactions...269
Figure 7–13 Chain termination step of Fischer-Tropsch
reactions resulting in alkanes (first two) or
alkenes (third)......................................................269
xxiv List of Figures
Figure 7–14 Theoretical dependence of mass fraction W of
n
Fischer-Tropsch products C –C on the chain
1 20
growth probability, a, according to the AFS
Eq.(7.44)..............................................................270
Figure 7–15 Theoretical cumulative distribution of Fischer-
Tropsch products according to the AFS Eq.(7.44),
for different values of growth probability, a.......271
Figure 7–16 Theoretical cumulative distribution of Fischer-
Tropsch products according to the AFS Eq.(7.44),
for different values of the growth probability, a...272
Figure 7–17 Theoretical composition of fuel product from
Fischer-Tropsch synthesis according to the AFS
Eq.(7.44), for different values of the growth
probability, a........................................................272
Figure 7–18 Theoretical composition of fuel products from
Fischer-Tropsch synthesis according to the AFS
Eq.(7.44), for different values of the growth
probability, a........................................................275
Figure 7–19 Types of Fischer-Tropsch reactors.............................279
Figure 7–20 Typical compositions of Fischer-Tropsch
products before and after hydrocracking............283
Figure 8–1 U.S. Underground natural gas storage facilities
in the lower 48 states...........................................291
Figure 8–2 Storage measures..................................................293
Figure 8–3 p/Z curve vs cumulative gas storage....................296
Figure 8–4 p/Z vs gas storage for Example8–2......................297
Figure 8–5 p/Z versus G plot for Example8–3......................299
s
Figure 9–1 The world energy mix, past, present, and future...305
Figure 9–2 World’s main natural gas proven reserves
holders compared to oil and coal........................309
Figure 9–3 The Wind potential of the United States at
50 land and offshore............................................311
Figure 9–4 Net electricity generation by energy source...........326
Figure 9–5 Wind electricity generation cost for three
US cities at discount rates (6%, 8%, and 10%)....326
Figure 9–6 Solar electricity generation cost for three
US cities at discount rates (6%, 8%, and 10%)....327
Figure 9–7 Historical CO emissions from electric power
2
sector....................................................................329
List of Tables
Table 1–1 Molecular Weights and Critical Properties of Pure
Components of Natural Gases........................................13
Table 1–2 Results for Example1–1..................................................13
Table 1–3 Calculated Results for Example1–3................................18
Table 1–4 PseudoCritical Properties for Example1–4.....................22
Table 1–5 Correlations to Calculate Pseudocritical Properties
fromg..............................................................................29
g
Table 1–6 Typical Units for Reservoir and Production
Engineering Calculations................................................33
Table 2–1 Results from Example2–5...............................................54
Table 2–2 API Recommended Performance Casing.........................56
Table 3–1 Correlations for non-Darcy Coefficient..........................61
Table 3–2 Results for Example3–1..................................................67
Table 3–3 PVT Table for Example3–3.............................................74
Table 3–4 Well and Reservoir Characteristics for Example3–4......79
Table 3–5 Results for Example3–4..................................................81
Table 3–6 Effects of Index of Permeability Anisotropy...................82
Table 3–7 Constants a and b............................................................91
Table 3–8 Material Balance Calculations for Example3–10.........110
Table 4–1 Types of Liquid/Gas Separators.....................................118
Table 4–2 Separator K Factors........................................................121
Table 4–3 k Values for Some Systems...........................................123
s
Table 4–4 Symbols used in Figure4–3...........................................125
xxv