university of texas at austin · 2017. 10. 17. · funnel viscosity seconds per quart (s/qt) 1.057...
TRANSCRIPT
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Contents
Figures vii
Tables xii
Foreword xiii
Preface xv
Acknowledgments xviiUnits of Measurement xviii
Introduction 1
1 Basic Concepts of Geology 3Uniformitarianism 5Geologic Time 10How the Earth Began 16Plate Tectonics 19The Mobile Crust 22Rifting 25Transform Faulting 26Convergence 27Rocks and Minerals 29Igneous Rock 31Sedimentary Rock 32Metamorphic Rock 32Summary 34
2 Sedimentation 35Origins of Sedimentary Particles 35
Clastics 35Pyroclastics 38Nonclastics 40
Sedimentary Transport 41Mass Movement 42Stream Transport 44Other Transporting Agents 46
Depositional Environments 47Continental Environments 47Transitional Environments 52Marine Environments 55
Sedimentary Facies 60Lithification 61
Compaction 62Cementation 62
Classification of Sedimentary Rocks 64Clastics 64
Stratigraphy 70
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Correlation 72Superposition 74Unconformities 75Faunal Succession 77Relative Age 78
Summary 82
3 Oil and Gas Accumulation 83Origin 85
Chemical Factors 85Biological Factors 86Physical Factors 88Source Rocks 89
Migration 89Primary Migration 90Secondary Migration 91
Accumulation 94Trapping 94Differentiation 97
Types of Traps 98Structural Traps 98Stratigraphic Traps 102Hydrodynamic Traps 108Combination Traps 110
Timing and Preservation of Traps 111Summary 112
4 Exploration 113Surface Geographical Studies 113
Aerial Photographs and Satellite Images 114Landsat 114Radar 115Oil and Gas Seeps 116
Collecting Data 117Private Company Libraries 117Public Agency Records 117Databases 117
Geophysical Surveys 118Magnetic and Electromagnetic Surveys 119Magnetometer Surveys 119Magnetotellurics 119Gravity Surveys 120Seismic Surveys 120Ocean Bottom Cable Systems 127
Reservoir Development Tools 129Well Logs 129Log Interpretation 135Sample Logs 136
Contents PRACTICAL PETROLEUM GEOLOGY
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Drill Stem Test 138Strat Test 138Stratigraphic Correlation 139Maps 140Data, Software, and Modeling Technology 143
Summary 146
5 Economics 147Summary of an Economic Analysis 151Availability of Mineral Rights 152Evaluation of Estimated Reserves 157Regulation Considerations 157Taxation Considerations 159Cash Flow Analysis 161Present Value Concept 163Risk Analysis 165Summary 168
6 Monitoring the Well 169Duties of the Geologist 170Logging 173
Sample Logs 173Wireline Well Logs 178Measurement While Drilling and Logging While Drilling 179
Formation Testing 189Formation Test Data 190Predicting Production Behavior 190
Completing the Discovery 191Evaluation 191Completion 191
Exploration Success 197Summary 198
7 Field Development 199Expanding and Maintaining Productivity 199
Selecting Well Sites 199Recovery Efficiency 202Plugging and Abandonment 204Describing the Reservoir 205
Estimating Reserves 218Volumetric Calculation 218Material Balance 221
Modeling 222Analog Models 222Simulation 222
Improving Recovery 223Drive Mechanism Enhancement 224Fluid Properties Enhancement 226Programs Addressing Heterogeneities 226
PRACTICAL PETROLEUM GEOLOGY Contents
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Summary 229
Afterword 231
Appendix: Figure Credits 233
Glossary 243
Index 275
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Throughout the world, two systems of measurement dominate: the English system and the metric system. Today, the United States is one of only
a few countries that employ the English system.The English system uses the pound as the unit of weight, the foot as
the unit of length, and the gallon as the unit of capacity. In the English system, for example, 1 foot equals 12 inches, 1 yard equals 36 inches, and 1 mile equals 5,280 feet or 1,760 yards.
The metric system uses the gram as the unit of weight, the metre as the unit of length, and the litre as the unit of capacity. In the metric system, 1 metre equals 10 decimetres, 100 centimetres, or 1,000 millimetres. A kilo-metre equals 1,000 metres. The metric system, unlike the English system, uses a base of 10; thus, it is easy to convert from one unit to another. To convert from one unit to another in the English system, you must memorize or look up the values.
In the late 1970s, the Eleventh General Conference on Weights and Measures described and adopted the Systeme International (SI) d’Unites. Conference participants based the SI system on the metric system and de-signed it as an international standard of measurement.
The Rotary Drilling Series gives both English and SI units. And because the SI system employs the British spelling of many of the terms, the book follows those spelling rules as well. The unit of length, for example, is metre, not meter. (Note, however, that the unit of weight is gram, not gramme.)
To aid U.S. readers in making and understanding the conversion system, we include the table on the next page.
Units of Measurement
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Quantity Multiply To Obtain or Property English Units English Units By These SI Units
Length, inches (in.) 25.4 millimetres (mm) depth, 2.54 centimetres (cm) or height feet (ft) 0.3048 metres (m) yards (yd) 0.9144 metres (m) miles (mi) 1609.344 metres (m) 1.61 kilometres (km) Hole and pipe di ame ters, bit size inches (in.) 25.4 millimetres (mm) Drilling rate feet per hour (ft/h) 0.3048 metres per hour (m/h) Weight on bit pounds (lb) 0.445 decanewtons (dN) Nozzle size 32nds of an inch 0.8 millimetres (mm) barrels (bbl) 0.159 cubic metres (m3) 159 litres (L) gallons per stroke (gal/stroke) 0.00379 cubic metres per stroke (m3/stroke) ounces (oz) 29.57 millilitres (mL) Volume cubic inches (in.3) 16.387 cubic centimetres (cm3) cubic feet (ft3) 28.3169 litres (L) 0.0283 cubic metres (m3) quarts (qt) 0.9464 litres (L) gallons (gal) 3.7854 litres (L) gallons (gal) 0.00379 cubic metres (m3) pounds per barrel (lb/bbl) 2.895 kilograms per cubic metre (kg/m3) barrels per ton (bbl/tn) 0.175 cubic metres per tonne (m3/t)
gallons per minute (gpm) 0.00379 cubic metres per minute (m3/min) Pump output gallons per hour (gph) 0.00379 cubic metres per hour (m3/h) and flow rate barrels per stroke (bbl/stroke) 0.159 cubic metres per stroke (m3/stroke) barrels per minute (bbl/min) 0.159 cubic metres per minute (m3/min)
Pressure pounds per square inch (psi) 6.895 kilopascals (kPa) 0.006895 megapascals (MPa)
Temperature degrees Fahrenheit (°F) degrees Celsius (°C)
Mass (weight) ounces (oz) 28.35 grams (g) pounds (lb) 453.59 grams (g) 0.4536 kilograms (kg) tons (tn) 0.9072 tonnes (t) pounds per foot (lb/ft) 1.488 kilograms per metre (kg/m) Mud weight pounds per gallon (ppg) 119.82 kilograms per cubic me tre (kg/m3) pounds per cubic foot (lb/ft3) 16.0 kilograms per cubic me tre (kg/m3) Pressure gradient pounds per square inch per foot (psi/ft) 22.621 kilopascals per metre (kPa/m) Funnel viscosity seconds per quart (s/qt) 1.057 seconds per litre (s/L) Yield point pounds per 100 square feet (lb/100 ft2) 0.48 pascals (Pa) Gel strength pounds per 100 square feet (lb/100 ft2) 0.48 pascals (Pa) Filter cake thickness 32nds of an inch 0.8 millimetres (mm) Power horsepower (hp) 0.75 kilowatts (kW)
square inches (in.2) 6.45 square centimetres (cm2) square feet (ft2) 0.0929 square metres (m2) Area square yards (yd2) 0.8361 square metres (m2) square miles (mi2) 2.59 square kilometres (km2) acre (ac) 0.40 hectare (ha) Drilling line wear ton-miles (tn•mi) 14.317 megajoules (MJ) 1.459 tonne-kilometres (t•km) Torque foot-pounds (ft•lb) 1.3558 newton metres (N•m)
°F - 32 1.8
English-Units-to-SI-Units Conversion Factors
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IntroductionAny examination of the subject of petroleum geology must first begin with a brief consideration of where the petroleum came from in the first place.The popular organic theory states that the hydrogen and carbon that
make up petroleum come from the remains of microscopic organisms that lived in the rivers and seas covering the Earth’s surface millions of years ago. As these organisms died, they fell to the ocean floor and mixed with silt, sand, and mud. Eventually, a thick body of sediments enriched by the organic remains accumulated on the bottom of the ocean.
Over a very long period of time, the great weight of the overlying sediments pushed the lower layers deep into the Earth and changed the bottom beds into rock. In such an environment, the high heat and intense pressure—along with bacteria, chemical reactions, and other forces—had a profound effect on the organic remains. The remains were transformed into petroleum, which subsequently found a home within the rock’s small porous spaces (fig. i.1).
Figure i.1 Petroleum formation
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nPETROLEUM AND NATURAL GAS FORMATION
SAND AND SILTROCK
OIL AND GAS DEPOSITS
SAND AND SILT
PLANT AND ANIMAL REMAINS
OCEAN50-100 MILLION YEARS AGO
OCEAN300-400 MILLION YEARS AGO
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Introduction PRACTICAL PETROLEUM GEOLOGY
One common misconception about the nature of petroleum is that it exists in large underground formations that are similar to flowing rivers and lakes. Instead, most petroleum is found within rocks. Some rocks have a high porosity and allow for a large amount of petroleum to reside in the pores. Other rocks have few pores, which allows for less petroleum (fig. i.2).
Over time, as the Earth shifted, folds, faults, and other formations opened new channels through which the petroleum in the rock layers could flow. Rock layers with high permeability allowed the petroleum to flow more easily through the rock’s pores, whereas rock layers with low permeability had the opposite effect (fig. i.3).
Eventually, the petroleum moved around and became trapped by impervious layers of rock. These areas—called traps—kept the hydrocarbons within porous layers of rock, thereby forming reservoirs. A reservoir’s size is determined by the amount of oil and gas it contains. A reservoir might be broad and shallow, narrow and deep, or any variation in size. And it is these reservoirs that drillers want to find and tap.
Armed with this knowledge of the origins of petroleum, we can now focus on the main topic of the book: petroleum geology.
Figure i.2 Porosity within rock (magnified view)
Figure i.3 Connected pores resulting in permeability (magnified view)
PORE
PORE
PORE
PORE
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PRACTICAL PETROLEUM GEOLOGY Basic Concepts of Geology
3
In this chapter:
• The principle of uniformitarianism
• Geologic time and the origins of the Earth
• Plate tectonics and the effects of a mobile crust
• Types of rocks and minerals
What comes to mind when you hear the word geology? We tend to think of geology in terms of landscapes too vast to fully comprehend—volcanoes, mountain ranges, canyons—created by forces beyond our control. We also tend to think of the beauty and power of the natural world—such as the landscapes in Arches National Park or the eruption of Mount St. Helens (figs. 1.1 and 1.2).
1Basic Concepts
of Geology
Figure 1.1 Arches National Park
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PRACTICAL PETROLEUM GEOLOGY Sedimentation
35
In this chapter:
• The means by which sedimentary rock is formed
• The transport and deposition of sedimentary particles
• Lithification and classification of sedimentary rocks
• The principles of stratigraphy
Because nearly all of the world’s supply of petroleum is found in sedimen-tary rock, it is the most interesting type of rock for petroleum geologists. To understand the correlation between petroleum and sedimentary rock, we must learn more about sedimentation—in other words, how sedimentary particles are formed, transported, deposited, and transformed into the great sheets of rock that cover most of the world’s land area.
The process by which sedimentary rock is formed can perhaps best be demonstrated by examining its smallest unit—the sedimentary particle. As does the rock as a whole, the individual particle embodies the history of both its source material and the changes it undergoes on the Earth’s surface.
Sediments are classified primarily by grain size (table 2.1). Gravel, sand, and silt particles can be of a variety of minerals—quartz and feldspar are common—while clay particles are microscopic platelets of various hydrous aluminum silicates. Gravel, sand, and silt are mostly noncohesive; that is, they do not stick together. Clay, on the other hand, is very cohesive; its particles are attracted to one another by minute electrical charges and adsorb water readily, causing clay to swell.
2Sedimentation
ORIGINS OF SEDIMENTARY PARTICLES
Clastics
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PRACTICAL PETROLEUM GEOLOGY Oil and Gas Accumulation
83
In this chapter:
• The origins of petroleum
• Primary and secondary migration of petroleum
• The methods by which petroleum accumulates
• Types of traps and their characteristics
For most of the time that humans have been aware of oil and natural gas, these substances were thought of as minerals that had formed out of nonliv-ing rock, such as gold, sulfur, and salt. Although oil had an odor suggesting organic matter and although natural gas burned like swamp gas, most of the gas and oil escaping from the ground seemed to come from solid rock deep beneath the surface, where nothing lived.
However, beginning about two centuries ago, the geologic insights of scientists such as James Hutton, Charles Lyell, and others showed that the rocks in which oil was found were once loose sediment piling up in shallow coastal waters where fish, algae, plankton, and corals had once lived. As a result of such insights, it seemed possible that oil and gas had something to do with the decay of dead organisms, just as coal, with its leaf and stem imprints, seemed to be the fossilized remains of swamp plants.
Later advances in microscopy revealed that oil-producing and oil-bearing rocks often contain fossilized creatures too small to be seen with the unaided eye. Chemists discovered that carbon:hydrogen ratios in pe-troleum are much like those in marine organisms and that certain complex mole cules are found in petroleum source rocks that are otherwise known to occur only in living cells. But it was the fact that most could be shown to have originated in an environ ment rich with life that clinched the organic theory of the origin of petroleum.
3Oil and Gas
Accumulation
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PRACTICAL PETROLEUM GEOLOGY Exploration
In this chapter:
• Collecting data using survey tools and databases
• The evolution of seismic surveys and interpretation
• Types of well logs and core samples
• Contour maps and digital models
In the past, exploring for petroleum was a matter of good luck and guesswork. In the early days of exploration, drilling near oil or natural gas seeps where hydrocarbons were present on the surface was the most successful method for finding hydrocarbons under the ground. Today, petroleum explorationists with extensive geologic training use sophisticated technologies and scientific principles and guidelines to find oil and gas.
Surface and subsurface geologic studies drive the discovery of oil and gas. Seismic data, well log data, aerial photographs, satellite images, gravity and magnetic data, and other geologic data provide information that help determine where to drill an exploratory well. Specialists examine rock frag-ments and core samples brought up while drilling the exploratory well and run special tools into the hole to get more information about the formations underground. By examining, correlating, and interpreting this information, explorationists can accurately locate subsurface structures that might contain hydrocarbon accumulations worth exploiting.
In relatively unexplored areas, petroleum explorationists study the topog-raphy of the surrounding land. The natural and manmade features on the surface of the land can help explorationists to draw conclusion about the character of underground formations and structures based largely on what appears on the surface.
4Exploration
SURFACE GEOGRAPHICAL STUDIESPetr
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PRACTICAL PETROLEUM GEOLOGY Economics
5Economics
In this chapter:
• Summary of an economic analysis
• Mineral rights and estimated reserves
• Regulation and taxation considerations
• Cash flow analysis, present value concept, and risk analysis
When the ultimate decision of whether to drill is made, other data are evalu-ated along with all of the preliminary geophysical and geologic evidence. Many of these added considerations are financial and practical ones. A mod-ern geologist has to be acquainted with the factors influencing wellhead and product pricing, transportation costs, fluctuations in supply and demand, associated political situations, and regulation and taxation, as well as the current costs of drilling.
All of these factors are balanced and weighed. Much of this type of evaluation is done at the managerial level of the operating company; however, because the geologist is often concurrently evaluating physical evidence, the two types of data become closely related. Therefore, some economic and legal knowledge on the part of the geologist is required.
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PRACTICAL PETROLEUM GEOLOGY Monitoring the Well
In this chapter:
• Methods for logging
• Formation testing
• Completion methods and equipment
• Initiation of flow and exploration success
The commitment to drill an exploratory well sets in motion a long chain of events. Well plans are engineered, and the site is surveyed and prepared for the drilling rig (fig. 6.1).
6Monitoring
the Well
Figure 6.1 Surveying using a global positioning system
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PRACTICAL PETROLEUM GEOLOGY Field Development
In this chapter:
• Productivity, efficiency, and types of maps
• Mathematical estimation of reserves
• Models and simulation
• Recovery improvement
Developing a field requires a solid grasp of regional geology and reliable well data. It is desirable to have a single geologist or a single team working on development because so much depends on the previous history of each drilled well. While the exploration program might call for perhaps three wells to locate the structural crest along a simple anticlinal structure, the development program moves to account for the complexities of the reservoir. Productivity within the structure will vary.
Selecting sites for the wells to succeed the discovery well requires the geologist to visualize the reservoir below the surface. Generally the position expected to be structurally highest will be drilled first. This and the next few well sites are commonly picked on the basis of the seismic picture. As wells are drilled, formation velocity surveys of the reflecting surfaces are made downhole. These surveys enable the seismic maps to be expressed more accurately in terms of depth; as a result, a better picture of the structural high can be generated. As subsurface contour maps are developed by the geologist, these maps replace the seismic picture for decision-making purposes.
7Field
Development
EXPANDING AND MAINTAINING PRODUCTIVITY
Selecting Well Sites
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PRACTICAL PETROLEUM GEOLOGY Energy Options and Policy
AfterwordA substantial portion of the process of delivering petroleum to the companies who sell it in its various forms and, subsequently, to the
consumers who buy it takes place long past the point when a geologist need be involved. But no part of the industry would exist if the petroleum were not first discovered where it had been slowly forming and collecting within the Earth for millions of years. And it is within this discovery phase that an understanding of petroleum geology is essential.
The petroleum geologist knows that the Earth is an ever-changing place and that the forces at work today have been at work for all of the bil-lions of years of our planet’s history. The petroleum geologist knows how organic matter was transformed in oil and gas over vast lengths of time. The petroleum geologist knows the properties of the rocks wherein the oil and gas hide and the irregularities within such rocks. The petroleum geologist knows how petroleum accumulates and migrates and the kinds of areas where it becomes trapped. The petroleum geologist knows how to explore formations and the ways in which to narrow the odds in favor of discovery. And based in part on these things that the petroleum geologist knows, companies in search of undiscovered oil and gas can analyze the economics of a venture, test the formations being drilled, and develop fields to meet the worldwide demand for oil and gas.
As was said at the outset of this book, unique challenges present themselves with each new drilling endeavor, and each well comes with its own particular set of traits. But in an inherently unpredictable field, the importance of the petroleum geologist and the knowledge she or he brings to bear remains constant.
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Index
Throughout this index, f indicates a figure and t indicates a table on that page.
accumulations of oil and gas. See oil and gas accumulationsacid fracturing, 196acid stimulation, 196acoustic impedance, 188acoustic logs, 134, 134f. See also sound wavesacre-feet in a reservoir, 157ad valorem taxes, 159adsorption, 35aeolian deposits, 52. See also wind transport of sedimentsaerial photographs, 114aerobic bacteria, 87air gun, 122, 127algae, 12, 18, 86alkane, 84allowable, 157–158alluvial fan, 51, 51fAlps, 28amphibians, Devonian period, 14Anadarko Basin, 25anaerobic bacteria, 87analog models, 222analysis, economic, 151andesite, 31angle of repose, 42angular unconformity, 75f, 76anhydrite, 68annular pressure, 185annular space, 185anomalies, micromagnetometer detecting, 119anticlines
hydrodynamic traps and, 108, 109foverview of, 78–79, 79fpetroleum accumulation and, 94, 95f, 96, 111–112traps, 98–99, 100, 101f
apron, fanglomerate, 51Arches National Park, 3fArchie, G. E., 136arenites, 66argon-40, 186arkose, 66aromatic hydrocarbons, 84, 85fasphalt, 73, 84asphalt seal trap, 107fasphaltic crude, 84associated free gas, 98
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Index PRACTICAL PETROLEUM GEOLOGY
Austin Chalk, 72, 72f, 106authority for expenditure, 156avalanche, 38. See also mass movement of sedimentsazimuth, 184, 184fazimuthal data, 181, 184
backbarrier complex, 54f, 55backshore zone, 54, 54f, 55bacteria, 12, 18, 87bar deposits, 50, 104basalt, 31base maps, 140basement rock, 119bauxite, 186beach sand trap, 104, 104fbeaches, 54–55, 54f. See also sandbed load, 45, 45fbedding planes, 42, 74, 74fbeds, marine delta, 53benzene ring, 84, 85fbiofacies map, 141bioherm trap, 105–106, 105fbiosphere, 63biostratigraphy, 139biotic community, 86–87, 86fbiotite, 38bismuth, 186block diagrams, 145, 145f, 213fblowout, 185blue-green algae, Precambrian era, 12, 18bonuses, land lease and, 152bottomhole assembly, 179, 180f, 181, 183fbottomhole money, 156bottomset beds, 53Bouguer gravity map, 140breccia, 65, 65fbrecciated fault trap, 106, 106f, 109buildup of fluid, 190bulk density, 187bulk modulus, 188buoyancy, petroleum migration and, 92, 92f, 109Bureau of Ocean Energy Management, Regulation, and
Enforcement, 156butadiene, 85fbutane, 84, 85f, 98butylene, 85f
calcite, 40, 62, 69Canyon de Chelly, 8fcapillarity, 93capitalizing drilling costs, 159–160, 160t
caprock, 110carbon, 1, 17, 84carbon dioxide, 12, 17, 38, 40, 69carbonate mud, 40, 56carbonate rocks, 63, 69carbonation, 38Carlsbad Caverns, 37, 37fcash flow, 149cash flow analysis, 151, 161–162catastrophism, 6, 10caverns, 106cementation, 62–64, 63fCenozoic era, 13f, 14, 112chemical testing for hydrocarbons, 116chemical weathering, 38chert, 64Christmas tree, 194, 194fclastics
cementation of, 63classification of, 64–67compaction of, 62overview of, 35–38texture of, 29, 29f
claycementation of, 62compaction of, 62, 62fgrain size of, 36tpetroleum migration in, 90properties of, 35slumping, 43
climate conditions, using in cost analysis, 161coal, 21, 69coastlines, 19, 19fColorado River, 7combination petroleum traps, 110compaction, 62, 62f, 188compaction anticline, 106completing a well. See well completioncompletion rig, 194, 194fcomposite log chart, 135fcompounding (present value concept), 163, 163fcompressional velocity, 188condensate, 202conductor line, 130cone-shaped charge, 195conglomerates, 64–66, 64fconing of water, 202connate water, 90contact, 74contact metamorphism, 33–34, 33fcontinental crust, 22–24, 22fcontinental depositional environment. See also
depositional environment
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PRACTICAL PETROLEUM GEOLOGY Index
aeolian deposits in, 52desert, 51fluvial deposits and, 48–51, 48fglacial, 52lacustrine, 51overview of, 47
continental drift, 19, 20f, 22–24, 26Continental Oil Company (Conoco), 125continental rifting. See riftingcontinental rise, 56f, 58continental shelf, 18, 56, 56fcontinental slope, 56f, 58continent-to-continent convergence, 27–28, 27fcontour maps, 57f, 140–141, 140f, 200f. See also maps;
structural mapsconvergence, plate, 27–28, 27fcoral reef, 57core samples, 136–138, 137f, 177, 177f. See also samplescoring bits, 136, 137fcorrelating rock formations, 72–73, 73fcost method, 160costs, planning for, 197creationism, 10Cretaceous period, 14, 23f, 69, 77, 214cross-cutting, relative age and, 82, 82fcrude oil, 84, 156, 218, 220crust, Earth, 9, 17f, 34crystalline texture, 29–30, 29f, 63cutting samples, 138, 173–176, 173f, 174tcyclohexane, 85fcycloparaffin, 84, 85f
darcy, 93data collection
decoding, 182ffor developing a well, 208ffor estimating reserves, 221ffrom formation tests, 190for a lithofacies map, 215tin marine environments, 128, 128ftechnology for, 143–144through libraries and public records, 117
databases, 117datum-referenced values, 207, 207fdecision tree, 148f, 151, 166, 167fdecomposition, aerobic, 87deliverability plots, 190density, measuring, 187Department of the Interior, 158depletion in taxation, 159deposition, 6, 48–51, 48f, 59depositional environment, 9, 47, 213–214. See also
continental depositional environment; marine environments
depreciation, 159desert environments, 51development plans, 203, 203fdevelopment well, 130, 150Devonian times, 214diagenesis, 61, 64, 69diapirism, 99diapirs, 110, 110fdiatomite, 69diatoms, 77, 77fdifferentiation, 97–98, 97fdimethyl cyclopetane, 85fdinosaurs, 14Dinoseis, 125diorite, 31dip, 78–79, 79f, 101dip slip fault, 80f, 81directional drilling, 150f, 179, 184disconformity, 75, 75fdiscounted cash flow rate of return, 164discounting (present value concept), 163discovery well, 149dissolved gas drives, 220dissolved load, 46division order, 156dolomite, 32, 69dolomitic limestone, 64dolomitization, 64dome, 98, 99fdoodlebugs, 121downcutting, 46fdrag fold, 102draped anticline, 79fdrawdown of fluid, 190drill collar, 181, 187, 188, 189drill stem test, 138, 178, 189, 189fdrill string components, vibrations and, 185driller’s log, 130drilling, expensing costs of, 159–160, 160tdrilling depth, 207drilling fluid, 170, 179drilling mud, 138drilling rates, 202drive mechanism enhancement, 224–225dry hole, 118, 150, 165–166, 165tdry hole money, 156dunefield, 54, 54f
Earthbeginnings of, 16–18
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Index PRACTICAL PETROLEUM GEOLOGY
cross section of, 17felements, 17estimating age of, 11–12
earthquakes, 8East Pacific Rise, 24, 26East Texas Field, 157economics in petroleum acquisition
availability of mineral rights, 152–156cash flow analysis, 161–162evaluating estimated reserves, 157MWD/LWD measurements and, 181overview of, 147–150plugging and abandoning wells, 204present value concept, 163–164regulation considerations, 157–158risk analysis, 165–167summary of analysis of, 151tax considerations, 159–160, 160tvolumetric calculation, 218–221
effective permeability, 94effective porosity, 92–93, 93fEl Capitan, 58, 58felectric logs, 131–132, 131f, 179felectromagnetic survey, 119electromagnetic transmissions, 181electron density, 187elevation, water and, 92Ellenburger Formation, 176, 213femulsion, 84environmental concerns, federal regulations and, 158epeiric seas, 56, 87erosion, 6f, 9, 32, 81estuary, 53ethane, 84, 85f, 98ethylene, 85fevaporites, 51, 68, 68f, 89expected value concept, 165–166, 165t, 166fexpensing drilling costs, 159–160, 160texplorationist, petroleum. See petroleum explorationistexploratory wells. See also petroleum exploration
committing to drilling, 169–170finding optimal locations for, 112, 129logs for, 171t, 172foffshore, 150
explosives, for seismic surveys, 124extrusive rock, 31
facies, sedimentary, 60–61, 60f, 104facies changes, 61, 104fanglomerates, 51farming out of leased lands, 149fault plane, 81fault scarp, 8, 8f
faultsdetermining relative age and, 80–81, 80foverview of, 26as a trap, 100–102, 100fvertical cross sections of, 142f
faunal succession, law of, 77Federal Energy Regulatory Commission, 158federal government, regulations and, 157–160Federal Power Commission, 158feldspar, 29, 66, 186field development
describing the reservoir, 205–217estimating reserves, 218–222improving recovery, 223–228modeling, 222–223plugging and abandoning wells, 204recovery efficiency, 202–203selecting sites, 199–202
fingering of water, 202fissuring, 36, 37fflooding, fluvial deposits and, 48–49, 49fflowing bottomhold pressure, 190fluid
buildup of, 190drawdown of, 190drilling, 170, 179enhancing properties of, 226formation, 179potential of, 91
fluorescence test, 174fluvial deposits, 48–51, 48fflysch deposit, 59folding, 78–80, 78ffoliated metamorphic rock, 34footwall in a fault, 81foraminifera, 40, 40fforeign countries, obtaining drilling rights in, 156foreset beds, 53foreshore, 54, 54fformation fluid, 190formation restivity, 136formation testing, 136, 189–190formation volume factor (FVF), 219–220fossil fuels, discovery of, 4fossils
cementation and, 63continental drift and, 20overview of, 10, 10fin sedimentary rock, 11, 72using to determining age of sedimentary rock, 77
four-component seismic data, 122, 123ffour-dimensional seismic data, 122
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fracturing, to stimulate well production, 196, 197ffree methane, 98frost wedging, 37, 37f, 42
gabbro, 31gamma ray logs, 132, 133f, 186gamma rays, natural, 186gas cap, 98, 200gas chromatograph, 176gas reservoirs. See natural gasgas-cap drive, 202, 220gas–oil contact, 97f, 98gas–water contact, 97f, 98geocellular model, 145geographic information system, 146geographical studies, surface, 113–117geologic concepts
convergence, 27–28crustal plates, 22–24Earth’s beginnings, 15–21geologic time, 10–15igneous rocks, 31metamorphic rock, 32–34overview of, 3–4rifting, 25–26rocks and minerals, 29–30sedimentary rock, 32transform faulting, 26uniformitarianism, 5–10
geologic processes. See also uniformitarianismapplying principle of uniformitarianism to, 8–9beginnings of Earth and, 16importance of understanding of, 4rate and magnitude of, 6–7, 9study of, 5
geologist, duties of, 170–173, 197. See also explorationist, petroleum; logging
geomorphic units, 213geophones, 120, 126geophysical surveys
gravity, 120magnetic and electromagnetic surveys, 119magnetometer survey, 119magnetotellurics, 119overview of, 118seismic surveys, 120–127
geophysics, 118geostatic pressure gradient, 88glacial environments, 47, 47f, 52glaciation, pre-Pleistocene, 20fglobal position system, 169fgold, 45gouge, 100
government, leasing from, 156grabens, 25graded stream, 46gradualism. See uniformitarianismgrain size, sediment classification by, 35, 36t, 66, 67Grand Canyon, 7, 7f, 72, 75–76, 76fgranite, 31, 31f, 66graphics, technology and, 144graphite, 88gravel, 35, 36tgravel packs, 196gravimeter, 120gravity, streams/sediment and, 41–42, 44gravity maps, 120gravity surveys, 120graywackes, 66growth fault, 80f, 81, 101fGulf of Mexico, 110, 122Gulf Production Company, 124gypsum, 51, 68
half-life, 11, 12fhalite, 51, 68hanging wall in a fault, 81heterogeneities, addressing, 226–228Himalayan mountains, 24, 28horizontal migration, 94, 95fhorizontal plate motion, 25horizontality, law of, 70, 71f, 78Horner, D. R., 190Horseshoe Atoll, 57, 57f, 106, 226f–227fhorsts, 25Hutton, James, 5, 83hydraulic fracture, 188, 196, 196fhydrocarbons. See also petroleum
accumulation of, 95, 95f, 96, 96faerobic decomposition and, 87basic reservoir types, 97fcomplexity of, 84examining cuttings for evidence of, 174migration of, 89, 89f, 91, 95fphysical transformation of, 88rate of change in volume, 219trapped, 2varieties of, 85f
hydrodynamic traps, 108–109, 109fhydrogen, 1, 84hydrogen sulfide, 87hydrolysis, 38hydrophones, 126hydrostatic pressure, 92
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ice sheets, continental drift and, 21igneous rock
magnetic surveys and, 119overview of, 28, 31, 31fstudying geologic past in, 70thorium release by, 186
imbrication in conglomerates, 65, 65fimpactors, 124, 124finclination of the well, 184income taxes, economic considerations and, 159induction log/survey, 132infill drilling, 202, 226inner core, 17, 17finorganic theory, 10–11intangible development costs, 159interface zone, 202interstices, 90interstitial water, 90, 94intrusive rock, 31iron, 17, 38iron oxide, 62island arc, 27isobutane, 85fisochore map, 141isolith map, 216, 216f, 217fisomers, 85fisopach map
examples of, 209f–212fuses in field development, 207–213, 214f, 219fuses in petroleum exploration, 141, 141f
isostasy, 22, 22fisotopes, 11
joint operating agreement, 156joints, in sedimentary particles, 36, 36fjug hustlers, 121jugs, 121Jurassic period, 23f
Kaibab Plateau, 7kaolinite, 38Kelly-Snyder field, 176
lacustrine environment, 51laminar flow, 44landforms, 6, 213landman, 148, 152Landmark Graphics, 144Landsat, 114, 115f
lateral continuity, law of original, 78lava, 31, 31flaw of original horizontality, 70, 71f, 78law of original lateral continuity, 78leaching, 37–38lead-207, 11leased lands
decisions over, 148, 149mineral rights and, 152multiple owners for a reservoir, 201, 201fposition of wellbore and, 184Producers 88 form, 153f–154f
lens trap, 105, 105flessee/lessor, 152libraries, using for collecting data, 117limestone
bioherm traps and, 106cementation and, 63, 63f, 64classification of, 69common nonclastic, 40during Earth’s formation, 18leaching of, 37as a source rock, 89strata in, 71f
liquefied petroleum gas (LPG). See petroleum gaslithic particles, 66lithification, 61, 62–64, 62f, 63flithofacies map, 141, 214–218, 215t, 217f, 228flithology log, 172floess, 52logging. See also geologist, duties of; well monitoring
cores, 177, 177fcuttings, 173–176, 174timportance of, 173measuring and logging while drilling, 179–189sidewall samples, 176–177, 176fwireline, 178, 178f, 179f
logging while drilling (LWD). See also measurement while drilling (MWD)
bottomhole assembly vibrations, 185density measurements, 187development of, 182–183magnetic resonance measurement, 188–189natural gamma ray measurement, 186neutron porosity measurements, 188overview of, 179–181resistivity, 187, 187fspectroscopy measurement, 189velocity measurements, 188
longshore currents, 54Los Angeles, California, recent earthquakes in, 26LWD. See logging while drilling (LWD)Lyell, Charles, 5, 83
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macroscopic heterogeneities, 226magma, 31magnetic field, 21, 119, 184magnetic resonance measurement, 188–189magnetic survey, 119magnetometer survey, 119, 184fmagnetotellurics survey, 119mammals, Mesozoic era, 14mantle, 17, 17fmaps. See also contour maps; structural maps
to describe the reservoir, 206–207examples of, 209f–212ffor exploration, 140–142, 144lithofacies, 214–218for selecting well sites, 199, 200fsubsurface, 205–206well location, 209f
marble, 32marginal well, 165–166, 165tmarine deltas, 53, 53fmarine environments. See also depositional environment
community within, 86–87, 86fdata collection in, 128, 128fouter continental, 58–59overview of, 55seismic surveys in, 126–128, 126f, 127fshelves, 56–58sound sources in, 127–128
marine invertebrates, Paleozoic era, 12marker beds, 73mass movement of sediments, 42–43. See also avalanchemass wasting, 41fmaterial balance, 221–222matrix acidizing, 196maximum efficiency rate, 158measurement while drilling (MWD). See also logging
while drilling (LWD)annular pressure, 185bottomhole assembly vibrations, 185development of, 182–183directional measurements, 184overview of, 179–181, 180fweight-on-bit and torque-on-bit, 185
megascopic heterogeneities, 227Mesozoic era, 13f, 14, 112metamorphic rock, 32–34, 33f, 70metamorphism, 28meteorites, 11methane, 17, 84, 85f, 88, 98mica, 29microfossils, 139microscopic heterogeneities, 226microscopic organisms, 1Mid-Atlantic Ridge, 21, 24
migration of petroleumdiffering owners of reservoir and, 201, 201foverview of, 89prevention of, 94primary, 89, 89f, 90secondary, 89, 89f, 91–93timing of, 111–112, 111f
millidarcy, 93Milne, David, 123mineral rights, availability of, 152–156minerals, 19, 29–30Mintrop, Ludger, 123–124models, for data interpretation, 145, 222–223, 222tmolasse, 51molecular weight, 84Monument Valley, 81, 81fMorrison Formation, 72Mount Everest, 24, 24fMount St. Helens, 4f, 38mountain ranges, 18, 28mud log/logger, 170, 171t, 176mudstone, 67multiple completion, 196MWD. See measurement while drilling (MWD)
naphthenes, 84, 85fnatural gamma rays, 186natural gas, 1f, 88, 98, 202neutron logs, 132neutron porosity, 188nonassociated gas, 98nonclastics, 40nonconformity, 75f, 76nonfoliated metamorphic rock, 34nonhorizontal rock layers, 78normal fault, 81North American plate, 26North Sea, 25nuclear logs, 132
oblique slip fault, 80f, 81obsidian, 31, 31focean bottom cable (OBC) seismic acquisition, 127–128ocean-to-continent convergence, 27–28, 27focean-to-ocean convergence, 27–28, 27foctane, 84offshore exploration. See also petroleum exploration
completion of, 192drilling exploratory and development wells in, 150four-component seismic sensor, 123fleasing, 156
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predicting costs for, 161three-dimensional seismic surveying in, 122
oil and gas accumulations. See also trapshistory of, 83migration, 89–93origins of, 84–89trapping and differentiation, 94–96
oil saturation, 97–98, 136oil shale, 69oil–water contact, 97f, 98, 108olefins, 85foolites, 40, 41fopen-hole wells, 196operators/owners, of one reservoir, 201–202, 201fOrdovician period, 77, 214organic theory, 1, 11, 83–84original horizontality, law of, 70, 71f, 78original lateral continuity, law of, 78orthoclase, 29orthorectified Landsat data, 114Outer Continental Shelf, leasing of, 156outer core, 17, 17foverriding royalties, 156overthrust fault, 80f, 81, 102foverturned fold, 79, 79foxbow lake, 51oxidation, 38oxygen, petroleum formation and, 87
Pacific plate, 26packers, 190, 192, 193fpaleoenvironmental analysis, 139Paleozoic era, 12–13, 13f, 77, 112Palmieri, Luigi, 123Pangaea, 14, 22, 23fparaffin, 84, 85fparty chief, 121pay zone, 157, 196, 197, 218Pennsylvanian period, 57percentage method, 160perforations, 191, 192, 193f, 195, 195fpermeability
changes in creating traps, 106–107, 106feffective, 94heterogeneities and, 226petroleum and, 2, 2frelative, 94in secondary migration, 93, 93f
Permian period, 23f, 57, 77petroleum. See also hydrocarbons
biological factors in formation of, 86–87chemical factors in formation of, 84, 85f
development of theories of origins of, 83–84differentiation, 97–98formation of, 1–2, 1f, 14limestone and, 69migration of, 89–93physical factors in formation of, 88reasons for failure to survive, 112sandstones and, 66shale and, 67source rocks for, 89time for formation and accumulation of, 89trapping, 94undiscovered, 5f
petroleum engineer, 189petroleum exploration. See also explorationist, petroleum;
exploratory wells; offshore explorationcollecting data for, 117geophysical surveys, 118–128reservoir development tools, 129–145risks in, 151, 165–167, 181surface geological studies, 113–117
petroleum explorationist, 113, 114, 150. See also geologist, duties of; petroleum exploration
petroleum gas, 84petroleum migration. See migration of petroleumpetroleum window, 88, 88fpetrophysical evaluations, 181petrophysicist, 186Petty, Dabney E., 124Petty, O. Scott, 124Petty Geophysical Engineering Company, 124Petty-Ray Geophysical, 124phosphorite, 69photosynthesis, 12, 17, 18physical laws, 6physical weathering, 36–38piezoelectric transducer, 188pinchout trap, 106, 106fpitch, 84plagioclase, 29plate convergence, 27–28, 27fplate tectonics, 19–21, 25–26playas, 51plugged and abandoned wells, 150, 204plunging fold, 79, 79fplutonic rock, 31plutons, 28polarity, Earth, 21pooling, 155, 155fporosity
cementation and, 64in estimating reserves, 218–219petroleum and, 2, 2fpetroleum migration and, 90
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in secondary migration, 92–93, 93fpotash, 68potassium carbonate, 38potassium-40, 186potentiometric surface, 91f, 92, 92f, 108Precambrian era, 12, 13fpresent value concept, 163–164, 163fpressure, 1, 222pressure build up, 185pressure buildup plots, 190price per barrel, assigning, 157, 221primary migration, 89, 89f, 90Principles of Geology (Lyell), 5probabilities, using in risk analysis, 165producers, competing on one reservoir, 201–202Producers 88 lease form, 153f–154fproducing zones, 191production casing, 193f, 194, 195fproduction platform, offshore, 192production taxes, 159productive acreage, in reserve estimation, 218productivity of wells. See also well monitoring
expanding and maintaining, 199predicting, 190recovery efficiency, 202–203selecting well sites and, 199–202
prograding delta, 53propane, 85f, 98proppant/propping agent, 196propylene, 85fproration policies, 157protoplanet hypothesis, 16–18, 16fprotozoa, 86proved reserves, 149public agency records, for collecting data, 117pumice, 31pump, to sustain oil production, 195pyroclastic rock, 31, 38, 39f
quartz, 29, 66
radar, 115radioactive elements, geologic time and, 11radioactivity logs, 132, 133freconnaissance survey, 119record section, 120recovery efficiency, 220recovery of reserves, improving
by addressing heterogeneities, 226–228efficiency in, 202–203overview of, 223
through drive mechanism enhancement, 224–225through fluid properties enhancement, 226
recumbent fold, 79, 79fRed Sea Rift, 24reefs, 40, 57, 105regional metamorphism, 33–34, 33fregulations in petroleum acquisition, 157–158relative age, in stratigraphy
classifying rocks by, 12, 13fcross-cutting, 82, 82ferosion, 81faulting, 80–81folding, 78–80, 78foverview of, 78
relative permeability, 94relative plate motion, 26remote sensing, 114, 115fremotely operated vehicle, 127reptiles, Pennsylvanian period, 14reserve recovery. See recovery of reserves, improvingreserves, estimating, 157, 218–222reservoirs. See also traps
estimating size of, 157seeps at, 116size of, 2
reservoir, gas, 202reservoir description
depositional environment, 213–214lithofacies maps, 214–218mapping the stratum, 205–213overview of, 205
reservoir development toolsacoustic logs, 134, 134fdata, software and modeling, 143–146drill stem test, 138driller’s log, 130electric logs, 131–132, 131flog interpretation, 135–136, 135fmaps, 140–142nuclear logs, 132, 133foverview of, 129sample logs, 136–138strat test, 138stratigraphic correlation, 139, 139fwell logs, 129, 129fwireline log, 130, 131f
reservoir rock, 89, 92, 93, 100resistivity, measuring, 187, 187fresistivity logs, 132, 132fresistivity of a formation, measuring, 136, 182reverse dip slip fault, 80f, 81rhyolite, 31rift zone, 22rifting, 25–26, 25f
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Rio Grande, 9fripple marks, 50risks, in petroleum exploration, 151, 165–167, 181rivers, channel shifting by, 9frock cycle, 30, 30frock salt, 68, 109rock stratigraphic units, 61, 73rock types
changes in, 64continental drift and, 19, 20foverview of, 29–30transitioning, 60–61
rockslides, 42, 42fRocky Mountain Overthrust Belt, 81, 102rollover anticline, 101, 101froyalty payments, 152, 156
sabkhas, 51salt domes, 68, 99, 110, 120samples, 11. See also core samplesSan Andreas Fault, 26, 26f, 81sand, 35, 36t, 62, 62f. See also beachessand dunes, 52sandbars, overlapping characteristics of, 49sandstone
cementation and, 63classification of, 66, 66fduring Earth’s formation, 18geologic processes and, 8petroleum migration in, 90physical weathering, 38
satellite images, 114satellites, for transferring data from ship to shore, 128saturated hydrocarbon, 84scarp, 8, 8fschist, 32scour marks, 50screen liners, 196seafloor magnetic anomalies, 21, 21fsealing fault, 100seawater, 40sebkhas, 51secondary migration, 89, 89f, 91–93sedimentary rock
catastrophism view and, 6classification of, 64–69during Earth’s formation, 18fossils and, 11overview of, 32, 32fsedimentary particles in, 35–41studying geologic past in, 71–72using faunal succession to determine age, 77
sedimentschemical weathering and, 38clastics, 35–38continental depositional environment, 47–52facies, 60–61, 60fglacier transport of, 47, 47fgravity and, 41–42impact of physical factors in transport of, 44–45, 44flithification, 61–64marine environments and, 55–59mass movement of, 42–43nonclastics, 40in organic theory, 1origins of, 35–40overlapping characteristics of, 49fphysical weathering and, 36–38pyroclastics, 38, 39fstratification of, 70, 70fstream transport, 44–46transitional environments, 52–55transport of, 41wind transport of, 46, 46f
seeps, oil and gas, 107, 107f, 116, 116fseismic data, 114seismic reflection profile, 125seismic surveys
data from, 121–122early methods of, 123explosive methods, 124marine methods, 126–128, 126f, 127fmodern land methods, 124–126, 124focean bottom cable (OBC) seismic acquisition,
127–128seismology, 120–121technology for interpretation of, 144
seismic waves, 124–126, 124fseismogram, 120, 121fseismographs, 120, 123seismology, 120–121seismometer, 123Seismos, 124sequence stratigraphy, 139severance taxes, 159shale
during Earth’s formation, 18overview of, 32, 67, 67fpetroleum migration in, 90as a source rock, 89
shale shaker, 170, 170fshaped charge, 195shear modulus, 188shear velocity, 188shelf environment, 56–58shoestring sand, 103, 103fshoreface, 54, 54f
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shot, 121, 124side-looking airborne radar (SLAR), 115sidewall samples, 176–177, 176fsilica, 29, 38, 62silt, 35, 36t, 45simulation of reservoirs, 222–223, 222tSinclair Oil and Gas Company, 125siren technique, 182SLAR. See side-looking airborne radar (SLAR)slate, 32slumping of clay hillsides, 43, 43fsodium bromide, 68sodium iodide scintillation counter, 186solar energy in petroleum, 86solution gas, 98sonde, 130, 131f, 132, 134fsonic logs, 134sound waves, 126. See also acoustic logssource rocks, 83, 89spectroscopy measurement, 189spontaneous potential log, 131, 131fsqueeze cementing, 204static bottomhole pressure, 190steam, using to generate sound waves, 128Steno, Nicolaus, 11, 74, 78step-out wells, 200stimulation treatment, 191, 196, 198strata, 70stratigraphers, 138stratigraphic correlation, 139, 139fstratigraphic tests, 73, 138stratigraphic traps, 102–107stratigraphy
correlation in, 72–73, 73f, 139defined, 138faunal succession, 77overview of, 70–72, 70frelative age, 78–82superposition, 74
stream downcutting, 41fstream meandering, 50–51, 50fstreams. See also water
imbrication of deposits in, 65transporting sediment, 44–46velocity of, 44, 48
strike, 78–79, 79fstrike slip fault, 80f, 81strip chart, 174, 175fstructural maps. See also contour maps; maps
dome on, 98, 99fexamples of, 209f–212ffor exploration, 140, 140ffor field development, 207–213
subduction zone, 27subsurface mapping, 205–206successful well, 165–166, 165tsulfides, 87superposition, law of, 74support agreements, 156surface geological studies
aerial photographs and satellite images, 114Landsat, 114, 115foil and gas seeps, 116, 116fradar, 115
suspended load, 45f, 46swabbing, 195synclines, 78, 79, 79f, 98
talus slopes, 42, 43ftax considerations in petroleum acquisition, 159–160,
160t, 162technology, for data interpretation, 143–146tectonic forces, 42Terra life scale, 14, 15fTethys Sea, 22, 23Texas Railroad Commission, 157–158thallium, 186thorium-232, 186three-dimensional seismic data, 116, 121–122, 122f, 144thrust dip slip fault, 80f, 81Thumper, 124–125, 125ftill, glacial, 52tillite, 66tilted anticlines, 108, 109ftime stratigraphic units, 61, 73time varying pressure wave, 182toluene, 85ftopographic maps, 140topography, 58, 72, 113, 145, 205topset beds, 53torque-on-bit, 185torsion balance, 120towed streamer acquisition, 127transform faulting, 26transition zones, hydrocarbon reservoirs, 98transition zones, marine environment, 59transitional environments
beaches, 54–55marine deltas, 53, 53foverview of, 52
trapping, 94, 95f, 96traps. See also oil and gas accumulations; reservoirs
combination, 110hydrodynamic, 108–109, 109foverview of, 2, 98
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stratigraphic, 102–107structural, 98–102timing and preservation of, 111–112
trenches, deep-sea, 21Triassic period, 23ftrilobites, 77, 77ftubing, 192, 193f, 194, 194f, 195fturbidite, 59, 59fturbidity current, 59turbulent flow, 44two-dimensional seismic data, 116, 120–121, 144
ultraviolet lights, used to observe cuttings, 174unconformities, 75–76, 75f, 82, 107, 107funiformitarianism, 5–10, 28. See also geologic processesUnited States Geological Survey (USGS), 114unitizing drilling units, 155, 155funproven areas, 149unsaturated hydrocarbons, 84upfront fees, 152uranium-235, 11, 12furanium-238, 186uranyl ion, 186U.S. Department of Energy, 158U.S. Internal Revenue Code, 159USGS. See United States Geological Survey (USGS)
velocity, measuring, 188vertical cross sections, 142, 142fvertical migration, 94vertical-cable survey, 126vibrations, protection from, 185Vibroseis, 125, 125fvolcanic arc, 28volcanic ash, 38volcanic rock, 31volcanoes during Earth’s formation, 18volumetric calculation, 218–221vugs, 106
water. See also hydrodynamic traps; streamsduring Earth’s formation, 18flow of, 91–92, 92fpetroleum accumulation and, 111physical weathering and, 37role in trapping petroleum, 94, 95f, 96, 96f
sea, 40sediment transport and, 44–46
water drive reservoir, 200, 202, 220water front, 202water saturation, 136, 219water vapor, 17water-wet reservoirs, 97waves, sediments and, 54–55weathering
chemical, 38physical, 36–38sedimentary rock and, 32
wedge-shaped formation, hydrodynamic trapping in, 109f
Wegener, Alfred, 19weight-on-bit, 185welded tuff, 38, 39fwells
describing, 205–217plugging and abandoning, 150, 204recovery efficiency, 202–203, 203fselecting sites, 199–202
well completionconventional, 191–195, 193fvariations of, 196
well inclination, 184well log data, 113, 129, 129fwell monitoring. See also logging
completing the discovery, 191–197evaluation of production possibilities, 191formation testing, 189–190geologist’s duties in, 170–173overview of, 169–170predicting production, 190successful wells and, 197–198
well sites, selecting, 199–202well spacing, 155, 158, 200wellhead, 147, 150, 159, 194wildcat wells, 149wind transport of sediments, 46, 46f. See also aeolian
depositswireline, 130, 181wireline formation test, 189wireline log, 130, 131f, 178, 178f, 179fworking interest, 152World War I, seismographs in, 123–124
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To obtain additional training materials, contact:
PETEXThe University of Texas at Austin
PETROLEUM EXTENSION SERVICEJ.J. Pickle Research Campus10100 Burnet Road, Bldg. 2
Austin, TX 78758
Telephone: 512-471-5940or 800-687-4132
FAX: 512-471-9410or 800-687-7839
E-mail: [email protected] visit our Web site: www.utexas.edu/ce/petex
To obtain information about training courses, contact:
PETEXLEARNING AND ASSESSMENT CENTER
The University of Texas4702 N. Sam Houston Parkway West, Suite 800
Houston, TX 77086
Telephone: 281-397-2440or 800-687-7052
FAX: 281-397-2441E-mail: [email protected]
or visit our Web site: www.utexas.edu/ce/petex
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