Oil & Gas Production Geology – 01 Overview Геологія видобутку нафти і газу – 01 короткий опис Вольфганг Нахтманн Wolfgang Nachtmann RAG Wien [email protected]
Oil & Gas Production Geology – 01 Overview
Геологія видобутку нафти і газу – 01 короткий опис
Вольфганг Нахтманн
Wolfgang Nachtmann � RAG � Wien
Oil & Gas Production Geology – 01 Overview | 2011 | 2
Content of Lecture
Зміст лекції
Oil & Gas Reservoirs – from uncontrolled eruptions to an optimum production strategy – geological and reservoir-relevant parameters and methods to develop oil & gas fields
Oil & Gas Production Geology – 01 Overview | 2011 | 3
Petroleum – a Basic Element Sine Qua Non
Нафта – обов‘язкові вимоги
In the twentieth century, oil, supplemented by natural gas, toppled King Coal from his throne as the power source for the industrial world.
Oil also became the basis of the great postwar suburbanization movement that transformed both the contemporary landscape and our modern way of life. Today, we are so dependent on oil, and oil is so embedded in our daily doings, that we hardly stop to comprehend its pervasive significance. It is oil that makes possible where we live, how we live, how we commute to work, how we travel—even where we conduct our courtships. It is the lifeblood of suburban communities.
Oil (and natural gas) are the essential components in the fertilizer on which world agriculture depends; oil makes it possible to transport food to the totally non-self-sufficient megacities of the world.
Oil also provides the plastics and chemicals that are the bricks and mortar of contemporary civilization, a civilization that would collapse if the world's oil wells suddenly went dry.
Prologue to The Prize by Daniel Yergin, 1991
Oil & Gas Production Geology – 01 Overview | 2011 | 4
What is Petroleum
Що таке нафта і газ
PETROLEUM A generic name for hydrocarbons, including crude oil, natural gas liquids, natural gas and their products.
Glossary of Petroleum Industry Common Terms & Symbols
Petroleum is crude oil, a naturally occurring liquid that can be distilled or refined to make fuels, lubricating oils, asphalt, and other valuable products. Used in a broad sense, petroleum also refers to natural gas and solid asphalt, …
Oil & Gas Production Geology – 01 Overview | 2011 | 5
The Value Chain of Petroleum Industry – Three Legs
Ланцюг вартості у нафтогазовій індустрії – три етапи
The oil industry can be divided into three major components: upstream, midstream and downstream.
The upstream industry includes exploration and production activities, hence is also referred as the exploration and production (E&P) sector.
The midstream industry processes, stores, markets and transports commodities including crude oil, natural gas, natural gas liquids (NGLs) like ethane propane and butane and sulphur.
The downstream industry includes oil refineries, petrochemical plants, petroleum products distributors, retail outlets and natural gas distribution companies.
In general, both, internationally and domestically, the oil and gas sector is characterized by the existence of "integrated" companies, which are present in all these three sectors.
Oil & Gas Production Geology – 01 Overview | 2011 | 6
Upstream: Exploration and Produktion (E & P)
Апстрім: Розвідка та видобуток (E & P)
Upstream sector, the first part of the oil and gas industry, deals with exploration and production of oil and gas. Oil exploration takes place at oil wells in four stages:
• the first stage is drilling, act of boring a hole through which oil or gas may beproduced if encountered in commercial quantities.
• the second stage is completion, process in which the well is enabled to produceoil or gas.
• the third stage is production, production time of oil and gas.• the final stage is abandonment, where the well no longer produces or produces
so poorly that it is a liability to its owner and is abandoned.
An oil field is a region with an abundance of oil wells extracting petroleum (oil) from below ground. Because the oil reservoirs typically extend over large(r) areas, full exploitation entails multiple wells scattered across the area. There are more than 40,000 oil and gas fields of all sizes in the world (BP statistical Review,2006) and the largest discovered conventional oil field is the Ghawar Field (75-83 billion bbl) in Saudi Arabia.
In tandem with the stagnated reserves, the production of oil has also been sluggish over the last decade, as a matter of fact during the last ten years oil production has increased by only 1.6%.
Oil & Gas Production Geology – 01 Overview | 2011 | 7
The World Consumes one Cubicmile of Oil per Year
Світ споживає одну кубічну милю нафти на рік
1 cubic mile of oil contains as much energy as we would get from 52 new nuclear power plants working for the next 50 years
Oil & Gas Production Geology – 01 Overview | 2011 | 8
Development of Worldwide Oil & Gas Reserves
Світова розробка резервів нафти і газу
Distribution of proved oil & gas reserves in 1988, 1998 and 2008Percentage
BP Statistical Review of World Energy 2009
Öl
Gas
Oil & Gas Production Geology – 01 Overview | 2011 | 9
Oil Reserves-to-Production (R/P) Ratios
Співвідношення резервів нафти до видобутку (R/P)
BP Statistical Review of World Energy 2010 BP Statistical Review of World Energy 2010
Oil & Gas Production Geology – 01 Overview | 2011 | 10
R/P Model
Модель R/P
0
5
10
15
20
25
30
2007 2017 2027 2037 2047 2057 2067 2077 2087 2097
Wor
ld A
nnua
l Oil
Pro
duct
ion
(bln
bbl
s)
Data base:� 2007 Reserves 1283 Mrd bbl� 2007 Production 29,8 Mrd bbl / a� R/P 41,6 years
R/P Model-Assumption:� stable production on 2007 level until
complete exhaustion of reserves
Oil & Gas Production Geology – 01 Overview | 2011 | 11
R/P Model Versus More Realistic Expectations
R/P модель у порівнянні з більш реалістичними очікуваннями
0
5
10
15
20
25
30
2007 2017 2027 2037 2047 2057 2067 2077 2087 2097
Wor
ld A
nnua
l Oil
Pro
duct
ion
(bln
bbl
s)
Assumption ignores that:� production from known fields won‘t
stay stable – an annual decline of 3% appears realistic
� New reserves will be added from exploration and field developments
Data base:� 2007 Reserves 1283 Mrd bbl� 2007 Production 29,8 Mrd bbl / a� R/P 41,6 years
R/P Model-Assumption:� stable production on 2007 level until
complete exhaustion of reserves
Oil & Gas Production Geology – 01 Overview | 2011 | 12
Reserves Additions: New Discoveries versus Existing Fields
Доповнення резервів: нові поклади у порівнянні з існуючими родовищами
Oil & Gas Production Geology – 01 Overview | 2011 | 13
Reservoir Management – Key to More Production from Old Fields
Менеджмент пластів – методи збільшення видобутку з нафтових родовищ
Oil & Gas Production Geology – 01 Overview | 2011 | 14
The Production Geologist – Member of a Multidiscipline Work Force
Геолог з видобутку – представник багатопрофільної робочої сили
A production geologist, in general, • works in a subsurface team • is responsible for understanding thegeological framework of the reservoir
• supports to understand how geologyinfluences fluid flow within a producing reservoir and creates „dead end pockets”that could eventually trap hydrocarbons (thebigger ones of these pockets may be worthtargeting with new wells)
• takes a leading role in planning such wells• typically uses computer software for a good part of his work
Oil & Gas Production Geology – 01 Overview | 2011 | 15
The Subsurface Team
Надра, команда
Oil & Gas Production Geology – 01 Overview | 2011 | 16
Reservoir Description – Data (Sources)
Опис пласта – дані (джерела)
Reservoir description is the base for a most effective and efficient reservoir management. Here, the production geologist plays a key role and will use a variety of data (sources), including:
• mud logging data• core data• sedimentology and petrography reports, studies• outcrop analogs / modern depositional environments• a broad spectrum of wireline log and logging-while-drilling (LWD) data• production log data• well test data• fluid samples• production data
• seismic data
Production Geologist � Static Model of Reservoir
Reservoir Engineer � Dynamic Model + Simulation of Flows
Common Target: maximization of production from an oil or gas field
Oil & Gas Production Geology – 01 Overview | 2011 | 17
Subsurface Techniques Over Time
Техніки розробки надр, основні етапи
Oil & Gas Production Geology – 01 Overview | 2011 | 18
Terminology Used in Appraising Oil & Gas Pools
Термінологія, що використовується при аналізі нафтогазових покладів
Oil & Gas Production Geology – 01 Overview | 2011 | 19
Continue with Chapter 02 – HC Basic Principles
Oil & Gas Production Geology – 02 Basic Principles
Геологія видобутку нафти і газу – 02 основні принципи
Вольфганг Нахтманн
Wolfgang Nachtmann � RAG � Wien
Oil & Gas Production Geology – 02 Basic Principles | 2011 | 2
GEOLOGICALSITUATION
MIGRATIONRESERVOIR
TRAPSEAL
MIGRATIONPATHS
TRAPOVERTIME
SOURCEROCK
MATURITYOF SOURCE
ROCK
Petroleum System Puzzle
Паззл нафтогазової системи
Oil & Gas Production Geology – 02 Basic Principles | 2011 | 3
The Petroleum System – Elements and Processes
Нафтогазова система – елементи та процеси
Oil & Gas Production Geology – 02 Basic Principles | 2011 | 4
Petroleum System Definition
Визначення нафтогазової системи
The essential elements and processes and all genetically-related hydrocarbons that occur in petroleum shows, and accumulations whose provenance is a single pod of active source rock.
Source: JMA 2000
Source RockSource RockMigration RouteMigration RouteReservoir RockReservoir RockSeal RockSeal RockTrapTrap
ElementsElements
МатеринськаМатеринська породапорода
ШляхШлях міграціїміграції
ПластоваПластова породапорода
НепроникливаНепрониклива породапорода
ПасткаПастка
ЕлементиЕлементи
GenerationGenerationMigrationMigrationAccumulationAccumulationPreservationPreservation
ProcessesProcesses
ФормуванняФормування
МіграціяМіграція
НакопиченняНакопичення
ЗбереженняЗбереження
ПроцесиПроцеси
Oil & Gas Production Geology – 02 Basic Principles | 2011 | 5
Schematic Cross Section through a Petroleum System
Схематична поперечна секція через нафтогазову систему
Predicting the location, type, and quality of hydrocarbon systems is critical to successful oil and gas development. Technology, such as seismic imaging and computer modeling, has improved the process in recent decades.
http://www.learner.org/courses/envsci/unit/text.php?unit=10&secNum=4
Oil & Gas Production Geology – 02 Basic Principles | 2011 | 6
Trap Type 1 – Anticlinale
Тип пастки 1 - антикліналь
http://www3.uakron.edu/geology/Foos/Energy/poil3.html
Oil & Gas Production Geology – 02 Basic Principles | 2011 | 7
Trap Type 2 – Fault
Тип пастки 2 – структурна пастка
Oil & Gas Production Geology – 02 Basic Principles | 2011 | 8
Trap Type 3 – Pinch Out
Тип пастки 3 – пастка виклинювання
Oil & Gas Production Geology – 02 Basic Principles | 2011 | 9
Trap Type 4 – StratigraphicТип пастки 4 - стратиграфічна
Oil & Gas Production Geology – 02 Basic Principles | 2011 | 10
HC-Trap Types in the Vienna Basin 1
Типи пастки вуглеводнів у Віденському басейні 1
Oil & Gas Production Geology – 02 Basic Principles | 2011 | 11
HC-Trap Types in the Vienna Basin 2
Типи пастки вуглеводнів у Віденському басейні 2
Oil & Gas Production Geology – 02 Basic Principles | 2011 | 12
View at a Petroleum System
Вигляд на нафтогазову систему
Source and Seal
ReservoirMonterey Fmt. – Gaviota Beach, Ca.
Oil & Gas Production Geology – 02 Basic Principles | 2011 | 13
E & P Cycle
Цикл розвідки та вибодутку (Р та В)
Discovery
Appraisal& Planning
Prospect-Definition
Field-Development
Reservoir
Management
Basin-Analysis,(Play) Concept(s)
Regional Geology,Data (Expl. History),
Analogies
E & P Cycle
EXPLORATION
PRODUKTION
Seismic,Gravimetry
Oil & Gas Production Geology – 02 Basic Principles | 2011 | 14
E & P Cycle
Цикл розвідки та вибодутку (Р та В)
Відкриття
Аналіз & планування
Визначення
перспективи
Розробка
родовища
Пласт
Менеджмент
Аналіз басейну,(комплексу) концепція(ї)
Регіональна геологія,дані (іст. розвідка),
аналогії
E & P Цикл
РОЗВІДКА
ВИДОБУТОК
Сейсміка,гравіметрія
Oil & Gas Production Geology – 02 Basic Principles | 2011 | 15
Continue with Chapter 03 – Reservoir Description
Вольфганг Нахтманн
Wolfgang Nachtmann � RAG � Wien
Oil & Gas Production Geology – 03 Reservoir Description
Геологія видобутку нафти і газу – 03 опис пласта
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 2
Sedimentary Rocks
Осадові породи
Practically, all rock-elements of a petroleum system are
sediments. So do, of course, almost all reservoir rocks.
� Clastic (siliciclastic) rocks (80-85% of the stratigraphicrecord)
� Carbonate sediments and rocks (10-15% of the stratigraphic record)
� Organic (carbonaceous) sediments and rocks
� Evaporites
� Volcaniclastic sediments and rocks
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 3
Integrated Study (Scale/Disciplines) – Micro- to Basin Scale
Інтегроване дослідження (масштаб/алгоритм) – масштаб від мікро- до басейну
Courtesy: Uli Bieg, RAG
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 4
Environments of Clastic Deposition
Середовище теригенних відкладів
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 5
Preliminary depositional model
Початкова літологічна модель
„River“ dominated delta
Courtesy: Uli Bieg, RAG
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 6
Log correlation – Digitalization of available data and storage in Petrel
Кореляція каротажу – електроний вигляд наявних даних та записів у Петрель
Courtesy: Uli Bieg, RAG
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 7
Idealized Succession – Flood-dominated river delta
Ідеалізований варіант – дельта річки, с переважанням течії
Outburst of ephemeral sediment laden floods
Trigger mechanism
Mouthbar
Con
fined
flo
w
River mouth
Un-
conf
ined
flo
w
Masterbeddingplanes
Courtesy: Uli Bieg, RAG
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 8
Synthetic Deposition model
Синтетична модель залягання
Courtesy: Uli Bieg, RAG
jet flow
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 9
A model of Subaqueous Slope Channel and Deep-Water Fan
Модель підводного похилого каналу та глибоководний конус виносу
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 10
(SCHOLLNBERGER et al 1974)
Deep water Fan Shapes
Глибоководні конусні виноси
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 11
Appraisal and Development of a Reservoir
Аналіз та розробка пласта
A sheet-like turbidite reservoir will need only a few wells to appraise and develop it.
Channelized turbidite reservoirs will require several wells for appraisal and development – due to this fact they may be less profitable.
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 12
Introduction – Deep-Water Depositional Models
Вступ – глибоководні літологічні моделі
Wedge-Top Basins
Foredeep Basin
Inner Axial Outer
Basinal TurbiditeSystem
modified from Mutti et al., 2003
Submarine Transport and Depositional Processes
Courtesy: Anne Bernhardt, SPODDS
Fold-Thrust-Belt
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 13
Submarine Depositional Processes – Turbidity currents and debris flows
Підводні літологічні процеси – турбідитний та уламковий потік
Courtesy: Anne Bernhardt, SPODDS
Sediment gravity flows: Subaqueous flows that are driven down slope by gravity acting on particles
Debris Flow Deposit Turbidite
Ta
Tb
Tc
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 14
Lithofacies – Debris Flow Deposits
Літофації – відклади уламкових потоків
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 15
Lithofacies – Debris Flow Deposits
Літофації – відклади уламкових потоків
2 cm2 cm 2 cm
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 16
Lithofacies – Turbidity current deposits
Літофації – відклади турбідитних потоків
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 17
Lithofacies – Turbidity current deposits
Літофації – відклади турбідитних потоків
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 18
Lithofacies – Turbidity current deposits
Літофації – відклади турбідитних потоків
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 19
Core of a Good Quality Reservoir Rock
Керн породи якісного пласту
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 20
Pore space filled with CalcitePore space filled with Calcite--cementcement
= no room for oil/gas= no room for oil/gas
Sandstone Reservoir – No Porosity
Пласт пісковика – ніякої пористості
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 21
� Carbonate sand usually consists either of (fragmented) skeletal remains or non-skeletal grains (e.g., molluscs,
corals, forams, algae, bacteria, and many others)
� Most organisms initially form unconsolidated carbonate sediments
� Coral reefs and microbial mats (e.g., stromatolites) are examples of more solid carbonate structures
� Carbonate mud (micrite) is commonly the product either of chemical precipitation or algal/bacterial activity (e.g., ooids, onkoids, pisoids)
� Dunham classification of carbonate rocks:
� Texturally-based subdivision (cf. clastics): mudstone, wackestone, packstone, grainstone, rudstone
� Organically bound framework during formation: boundstone
Carbonate Rocks
Карбонатні породи
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 22
Tropical Carbonate Platforms: Facies Belts
Тропічні карбонатні платформи: фаціальні зони
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 23
Franconian Jurassic – Examples for Porosities in Carbonates
Франконський ярус, Юра – приклади пористості у карбонатах
Kalk-Stbr.-Ittling Dolomit-Stbr.-Bernhof
Courtesy: Roman Koch, GZ Nordbayern
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 24
Fractured Carbonate Rock
Роздроблена карбонатна порода
Oil & Gas Production Geology – 03 Reservoir Description | 2011 | 25
Continue with Chapter 04 – Reservoir Parameters
Oil & Gas Production Geology – 04 Reservoir Parameters
Геологія видобутку нафти і газу – 04 параметри пласта
Вольфганг Нахтманн
Wolfgang Nachtmann � RAG � Wien
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 2
Key Reservoir Description Needs
Основні характеристики пласта
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 3
Example of a Structure Map
Приклад структурної карти
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 4
Reservoir Distribution
Розповсюдження пласта
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 5
Trap – a Matter of Reservoir Discontinuity Reasons
Пастка – через уривчастість пласта
Source: McMoRan, 2010
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 6
Reservoir Thickness and Barriers
Потужність пласта та ізоляція
Gross paytotal thickness of the reservoir unit
Net paythe fraction of the reservoir that has porosity above a minimum threshold (this is the sum of the productive zones)
Reservoir barriersReservoirs are heterogeneous in both vertical and horizontal dimension at all scales. This is due to Stratigraphic facies changes, faults, variation in diagenetic features such as cementation or dissolution, etc. A huge body of data is needed to adequately characterize most reservoirs. Most often reservoir barriers are revealed by the pressure history of neighboring wells.
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 7
Definitions: from Reservoir to Net Pay
Визначення: від пласта до ефективної нафтонасиченої потужності
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 8
Porosity model for a shaly sand reservoir (from Al-Ruwaili et al.1 © 2004 SPE)
Модель пористості для сланцевого піскового пласта (з Al-Ruwaili et al.1 © 2004 SPE)
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 9
Field Development after a Discovery Well
Розробка родовища після свердловини, що відкрила родовище
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 10
Initial Field Evaluation
Початкова оцінка родовища
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 11
Full Field Development
Повна розробка родовища
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 12
Terminology of Reservoir Related Parameters 1/2
Визначення параметрів, стосовно пласта 1/2
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 13
Terminology of Reservoir Related Parameters 2/2
Визначення параметрів, стосовно пласта 2/2
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 14
Terminology of Fluid Contacts in Reservoirs
Визначення контактів флюідів у пласті
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 15
Pressure Gradients while Drilling through Different Media
Градієнти тиску під час буріння при різних умовах
Pressure gradients encountered while drilling depend on the penetrated media
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 16
Hydrocarbon Column
Висота покладу вуглеводнів
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 17
Reserves Estimation in a Field Over Time
Оцінка резервів родовища упродовж часу
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 18
Effect of Fluid Contacts on Volumetric Maps
Вплив контакту флюідів на волюметричні карти
Typical isopach maps of reservoirs when the fluid contact is above the sand base
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 19
Isopach Maps – Inner and Outer OWC
Карта рівної товщини – внутрішній та зовнішній водонафтовий контакт
Isopachs when the fluid contact is below the sand base
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 20
Anticlinal Traps and Spill Point
Антиклинальні пастки та точка максимальної насиченості пласта
Where are spill points of these structures?
Is any of the structures filled?
Are there not yet drilled prospects on this map?
What is the faults‘ role?
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 21
Porosity
Пористість
Porosity
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 22
Porosity
Пористість
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 23
Porosity
Пористість
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 24
Total versus Effective Porosity
Повна та ефективна пористість
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 25
Types of Porosity
Типи пористості
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 26
Methods of Measuring Porosity
Методи виміру пористості
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 27
Porosity Measurement from Core
Вимір пористості з керну
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 28
Porosity from Logs
Пористість з каротажу
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 29
Characteristics of Logs
Параметри каротажу
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 30
Rock Types and Their Porosities
Типи пород та їх пористість
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 31
Reservoir Rock versus Trap Rock
Пластова порода та пасткова порода
www.priweb.org/.../reservoir/reservoir.html
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 32
Characteristics of Porosity
Параметри пористості
Effective porosity vs. total porosity Types:
Primary porositySecondary porosityPorosity in Clastic rocks vs Carbonate rocksRelationship between porosity and permeability
Depositional aspects:CompositionSortingRoundingGrain sizePacking
Diagenesis:DewateringCompactionCementation
What is good porosity?
0-5% - Negligible 5-10% - Poor 10-15% - Fair 15-20% - Good >20% - Very good
Practical cut off for oil Sandstone ~8% Limestone ~5% For gas the cut off is lower
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 33
Porosity in Carbonates
Пористість у карбонатах
http://strata.geol.sc.edu/thinsections/diagenesis.html
Depositional porosity is a function of rock texture, grain sorting and shape. Sorting and shape in turn are related to bottom agitation at the depositional site. Where currents and waves are particularly active, lime mud is winnowed from carbonate sands. In contrast, lime muds tend to collect in less agitated environments or where trapped by organisms, and after the sediment dewaters little or no porosity is retained. Many of the world's larger carbonate reservoirs have porosities that are largely depositional in origin.
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 34
Relationship Between Carbonate Diagenesis and Porosity
Відношення між карбонатним диагенезом та пористістю
The relationship between porosity and diagenesis is complex and variable. The major diagenetic processes affecting porosity are dissolution, cementation and dolomitization.
Each process requires a permeable host rock and a mechanism to flush chemically active waters through the rock. The water movement is controlled regionally by the hydrostatic head, structure and rock fabric.
Dissolution creates and enhances porosity. Commonly, however, dissolution of carbonate grains is accompanied by calcite cementation in adjacent primary pores. The end product in such a case is tightly cemented carbonate sand with well-developed moldic porosity and low associated permeability.
Cementation is an extremely important diagenetic process because it reduces porosity. The degree of cementation varies from thin cement coatings around the grains that partially fill the pores and alter permeability patterns to calcite spar that completely fill the pores.
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 35
Permeability
Проникливість
Permeability
“Permeable” is “Porous,” but “Porous” May Not Be “Permeable”
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 36
Permeability
Проникливість
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 37
Permeability
Проникливість
This is the key parameter in determining reservoir quality. Many rocks (e.g. shales, chalk) have high porosity, but very low permeability. Determined from Darcy's law.
Main controls on permeability are:
• Grain size (determines the size of the pore throats) • Pore connectivity
Effective permeability: When multiple fluids are present they interfere with each other. So that the effective permeability of the moving fluid is much lower than if a single fluid is present. In a typical reservoir at least water and oil are present, frequently water, oil, and gas share the pore space.
What is good permeability?
<1 millidarcy - Poor 1-10 md - Fair 10-100 md - Good 100-1000 md - Very good
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 38
Permeability is a Function of:
Проникливість є функією:
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 39
Porosity – Permeability Correlation
Кореляція пористості та проникливості
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 40
Increase/Reduction of Porosities and Permeabilities
Підвищення/зменшення пористості та проникливості
Processes that reduce porosity and permeability:
• Compaction • Cementation • Heavy hydrocarbon residue
Processes that enhance porosity and permeability:
• Dissolution • Fracturing • Dolomitization
Carbonate rocks are often subjected to early cementation, so reservoir quality depends very strongly on dissolution, fracturing and dolomitization. Most carbonate reservoirs are due to secondary porosity. Reefs sometimes preserve primary porosity.
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 41
Capillary Pressure
Капілярний тиск
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 42
Fluid Distribution within a Reservoir
Розповсюдження флюідів всередині пласта
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 43
Reservoir Quality
Якість пласта
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 44
Capillary Pressure Curves
Криві капілярного тиску
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 45
Reservoir Engineering aspectsthe Production Geologist should
be aware of
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 46
Reservoir Engineering Tasks
Завдання технології розробки
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 47
Building a Reservoir Description
Структура опису пласта
Oil & Gas Production Geology – 04 Reservoir Parameters | 2011 | 48
Continue with Chapter 05 – Reservoir Fluids
Oil & Gas Production Geology – 04 Reservoir Fluids
Геологія видобутку нафти і газу – 04 пластові флюіди
Вольфганг Нахтманн
Wolfgang Nachtmann � RAG � Wien
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 2
Hydrocarbon Content – Production Data
Об'єм ВВ – виробничі дані
Assessment and Adaption of volumetric reserves by production history
„dynamic methods“ for oil & gas reservoirs
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 3
Dynamics
Динаміка
Production (Exploitation) is governed by Reservoir Fluid(s) and their Drive Mechanism
The relations are provided by
Material BalanceSimulation
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 4
Calculation of Volumes
Розрахунок/параметри об‘єму
at standard conditions
Oil: 1,01325 [bar(a)] 15 [°C]
Gas: 1,01325 [bar(a)] 0 [°C]
Transformation from reservoir to surface via
„Formation Volume Faktor“ B ;
B = V Reservoir / V Standard conditions
Bo, Bg from PVT analysis in labs or from correlation
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 5
PVT Correlation for Oil
PVT кореляція для нафти
� Standing
� Lasater
� Vasquez and Beggs
� Petrosky
� Beggs and Robinson for oil-viskosity
Evaluated Data:
Bubble Point Pressure Pb [psia oder bara]
Solution GOR Rs [scf/STB oder Sm3/m3]
Formation Volume Factor Oil Bo [RB/STB oder Rm3/m3]
(saturated oil)
Oil-Viskosity µo [centiPoise]
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 6
Formation Volume Factor (FVF), B for Oil
Фактор формування об‘ємів, B для нафти
Two Phases:
• P > gas dissolution pressure P b
Bo increases with pressure reduction
Bo decreases with pressure reduction
PReservoir
Bo
1 Pb
2 Phases FVF, BT
• P < gas dissolution pressure P b
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 7
Formation Volume Factor (FVF), B for Gas
Фактор формування об‘ємів, B для газу
One Phase
The Volume develops disproportionalto the Pressure
Bg ~ 1 / PReservoir
Correction necessary since natural gas is not an „ideal“ gas
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 8
Gas Reservoir
Газовий пласт
Natural gas is a „real“ gas
Deviations from the ideal p.V/T = constant. Behavior described by the z-factor, „real gas favtor“
• gas composition (approximated via density ρρρρ)
• pressure
• temperature
Z-Factor depends on
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 9
Z – Real Gas Factor
Z – фактор реального газу
Gas reservoir:
0,7
0,8
0,9
1
1,1
1,2
0 100 200 300 400 500Pressure [bar]
z [-]110 [°C]90 [°C]70 [°C]50 [°C]30 [°C]10 [°C]
z-“real gas factor“ for natural gas, ρρρρ = 0.565 (Luft =1)
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 10
Dynamic Hydrocarbon Calculation
Динамічне визначення об‘єму ВВ
Oil volume (OIP), N
Gas volume (SGIP, GIP), G
Np Gp Wp
Method for „dynamic“HC-volume definition:
Aquifer
Winj
P
„Tank“ for MB, simulation cell
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 11
Untypical Oil-Water Contact Configurations
Нетипове розташування контакту води з нафтою
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 12
Drive Mechanisms in Reservoirs
Механізми імпульсу в пластах
� Expansion drive (Expansion of Fluids) � Volumetric gas reservoir
� Oil reservoir without gas cap
� Water drive� Natural water drive by aquifer expansion
� Compaction� Compaction of reservoir by overburden
� Water injection� Pressure maintenance in reservoir by water
injection
� Gas(Re)injection� Pressure maintenance in reservoir gas
injection
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 13
Example(s) for Oil Reservoirs
Приклад(и) нафтових пластів
Oil field
0
50
100
150
200
0 1000 2000 3000 4000 5000Oil Production [m³ or t]
Pressure [bar]
Oil expansion
Int. Gas, Gas cap Water drive
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 14
Graph for Gas Equation
Графік для газового рівняння
0
50
100
150
200
0 100 200 300 400 500Gp Mio [Nm³]
P/z [bar] Scheme for a graphic material balance
„depletion drive“
„displacement“
overpressuredreservoir G
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 15
Example of a Graphic Material Balance
Приклад графічного балансу матеріалів
0
50
100
150
200
0 100 200 300 400 500Gp Mio [Nm³]
P/z [bar]
Pi/zi
Well 2Well 3Well 4
Result:
„depletion drive“ without water, G = 490 Mio [Nm³]
G0
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 16
Scheme for Well Test
Схема випробування свердловини
HC prone Formation
Fluid (O, G, W)
Pressure
Rate (Volume, Time)
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 17
Well Test – 1. Flow Period
Випробування свердловини – 1. робоча фаза
Procedure for OHT and CHT:
Rate
Time
Time
1. Flow period
t1
Pressure
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 18
Well Test – 1. Pressure Build Up
Випробування свердловини – 1. зміна тиску
Time
Time
1. Pressure build up
∆∆∆∆t1
Rate
t1
Pressure
Procedure for OHT and CHT:
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 19
Well Test – 2. Flow Period
Випробування свердловини – 2. робоча фаза
Time
Time
2. Flow period
t2
Rate
t1 ∆∆∆∆t1
Pressure
Procedure for OHT and CHT:
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 20
Well Test – 2. Pressure Build Up
Випробування свердловини – 2. зміна тиску
Time
Time
2. Pressure build up
t2 ∆∆∆∆t2
Rate
∆∆∆∆t1t1
Pressure
Procedure for OHT and CHT:
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 21
Well Test – Pressure Build Up Interpretation 1/7
Випробування свердловини – аналіз результатів зміни тиску 1/7
-0.5
0.5
1.5
2.5
-1.5 -0.5 0.5 1.5 2.5
Diagnostic - PlotLog p
Log t
1. Pressure build up
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 22
-0.5
0.5
1.5
2.5
-1.5 -0.5 0.5 1.5 2.5
Diagnostic - PlotLog p 1. Pressure Build Up
derivative
Well Test – Pressure Build Up Interpretation 2/7
Випробування свердловини – аналіз результатів зміни тиску 2/7
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 23
Well Test – Pressure Build Up Interpretation 3/7
Випробування свердловини – аналіз результатів зміни тиску 3/7
-0.5
0.5
1.5
2.5
-1.5 -0.5 0.5 1.5 2.5
Diagnostic - PlotLog p 1. Pressure build up
2. Pressure build up
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 24
Well Test – Pressure Build Up Interpretation 4/7
Випробування свердловини – аналіз результатів зміни тиску 4/7
100
120
140
160
0.0 0.2 0.4 0.6 0.8 1.0
Nach Horner:
pressure
(t+dt)/dt
1. Pressure build up
2. Pressure build up
-0.5
0.5
1.5
2.5
-1.5 -0.5 0.5 1.5 2.5
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 25
Well Test – Pressure Build Up Interpretation 5/7
Випробування свердловини – аналіз результатів зміни тиску 5/7
100
120
140
160
0.0 0.2 0.4 0.6 0.8 1.0
Nach Horner:
(t+dt)/dt
1. Pressure build up
2. Pressure build up
pressure
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 26
Well Test – Pressure Build Up Interpretation 6/7
Випробування свердловини – аналіз результатів зміни тиску 6/7
100
120
140
160
0.0 0.2 0.4 0.6 0.8 1.0
Nach Horner:
pressure
(t+dt)/dt
permeability, k 1
permeability, k 2
k1 ~ k2
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 27
Well Test – Pressure Build Up Interpretation 7/7
Випробування свердловини – аналіз результатів зміни тиску 7/7
100
120
140
160
0.0 0.2 0.4 0.6 0.8 1.0
Nach Horner:
pressureP* ... Reservoir pressure
Inclination 2m:1m ... Fault
m2m
(t+dt)/dt
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 28
Initial Saturation
Початкова насиченість
Capillary pressure measurement at core samples
via:
• porous Diaphragma
• centrifuge
• mercury capillary pressure measurement
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 29
Saturation Distribution 1/2
Розподілення насиченості 1/2
Result of capillary pressure measurement[bar]
Water saturation, Sw [%]
0
100
200
300
0 20 40 60 80 100
k = 2000 [mD]
k = 20 [mD]
Pc
equivalent to height of HC column
h = Pc /(ρρρρw - ρρρρo)g
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 30
Saturation Distribution 2/2
Розподілення насиченості 2/2
-10
0
10
20
30
40
0 20 40 60 80 100
k = 2000 [mD]
k = 20 [mD]
Water saturation, Sw [%]
h[m]
Free Water Table
capillary water
Irreducible water
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 31
Fluid Distribution within a Reservoir
Розподілення флюідів всередині пласта
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 32
Producing Behavior of an Oil Column
Робочій режим/характер нафтового стовпа
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 33
Value of Information
Отримання інформації
Value of Information
Tests:• influx (gas, oil, water and their ratios)
• pressure (initial, reduced; limited reservoir; tight)
• rate (initial rates, production behavior; permeabilities)
Capillary pressure measurements:• saturations (control of volumetrics)
• permeabilities
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 34
Definition of Recovery Factor (RF)
Визначення фактору витягання з нафтового пласта
� the Recovery Factor RF is a product of:
� ED ….. Displacement Efficiency
� EV……. Vertical Sweep Efficiency
� EA ……. Areal Sweep Efficiency
RF = ED * EV * EA
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 35
Displacement Efficiency ED
Коефіціент витіснення ED
� depends on saturation ratios
� initially Soi (initial oil saturation), Swi (initial water saturation)
and
� at production end Sor (residual oil saturation)
� Soi = (1 – Swi)
� ED = (Soi - Sor) / Soi z.B.: Swi = 0.3 ( Soi = 0.7), Sor = 0.3
� ED = (0.7 – 0.3 ) / 0.3 = 0.571429
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 36
Sweep Patterns
Витіснення
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 37
Sweep Patterns
Витіснення
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 38
Vertical Sweep Efficiency EV
Ефективність вертикального витіснення з пласта EV
� depends on:
� heterogeneity in the reservoir (permeability profile)
� dip of reservoir layer(s)
� mobility ratio of displaced fluid (oil) and displacing fluid (water or gas)
� Density difference between displaced (oil) and displacing fluid (water or gas)
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 39
Areal Sweep Efficiency EA
Ефективність витіснення за площею EA
� depends on:
� Heterogeneity of the reservoir
� Mobility ratio between displaced fluid (oil) and fluid to be displaced (water or gas)
� Pattern of production and injection wells
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 40
Factors Influencing why Oil is Left Behind in Oil Fields
Фактори впливу на залишки нафти позаду пласта
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 41
Attic Oil
Нафта продуктивного пласта над стовпом горизонтальної свердловини
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 42
When Drilling Becomes Uneconomic
Коли буріння стає нерентабельним
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 43
Maturity Pie Chart of an Oil Field
Секторна діаграма зрілості нафтового родовища
Oil & Gas Production Geology – 05 Reservoir Fluids | 2011 | 44
Continue with Chapter 06 – Reserves
Oil & Gas Production Geology – 06 Reserves Assessment
Геологія видобутку нафти і газу – 06 підрахунок запасів
Patos Marinza Heavy Oil Field, Albania
Вольфганг Нахтманн
Wolfgang Nachtmann � RAG � Wien
Oil & Gas Production Geology – 06 Reserves Assessment | 2011 | 2
Reserves versus Resources – the BIG Difference
Резерви та ресурси – ВЕЛИКА різниця
Resources are always much higher than Reserves.
In a classification of geological resources (mineral commodities, coal, oil, gas) we usually differentiate between reserves that can be produced economically today with existing technology and at given prices, and potential respectively prospective resources which can only be produced with improved technologies and at higher prices in the future.
Oil & Gas Production Geology – 06 Reserves Assessment | 2011 | 3
Resources Classification System
Система класифікації ресурсів
Oil & Gas Production Geology – 06 Reserves Assessment | 2011 | 4
Gas in Place (GIIP) and Ultimate Recovery (UR)
Геологічні запаси та максимальне витягання
GIIP = A x h x Ф x (1 – Sw) x Bgi
GIIP gas initially in place (m³)
A area (m²)h net pay (m)Ф porosity (%)Sw water saturation (%)Bgi formation volume factor
UR ultimate recovery (m³)
RF recovery factor (%)
UR = GIIP x RF
Reserves = UR - Production
Oil & Gas Production Geology – 06 Reserves Assessment | 2011 | 5
Reserves Classification Terms
Умови класифікації резервів
� Proved
� „Very Likely“ – reserves exhibiting a low degree of uncertainty (~ 90 % confidence level)
� Probable
� „Likely“ – reserves exhibiting low to moderate degree of uncertainty
� Possible
� Potential – reserves exhibiting moderate to high degree of uncertainty
Oil & Gas Production Geology – 06 Reserves Assessment | 2011 | 6
Why are Reserves Important?
Чому резерви важливі?
� Proved
� Generally only category reportable to regulatory agencies
� Generally only category used by lenders
� Probable
� Combined with proved, often the basis for field development plans and commitments (Business Planning!)
� Possible
� Identifies upside potential and areas for further investigation and data collection.
Oil & Gas Production Geology – 06 Reserves Assessment | 2011 | 7
Evaluation Methods
Методи оцінки
� Volumetric Approach (Early Life, Performance Not
Indicative, Complex Reservoirs, Always an Essential Baseline)
� Map, Calculate OIP, Recovery Factor
� Analogy
� Reservoir Simulation
� Performance Approach ( More Mature Fields, Performance Trends
Established, Limited Additional Development, Volumetrics Still Informative)
� Decline Analysis
� Material Balance
� Reservoir Simulation
� Analogy