EXPLORATION GEOPHYSICSIntroduction

Dr. Ir. Eko Widianto, MT

Semester Genap_2013 - 2014

Program Studi Teknik GeologiFakultas Teknologi Kebumian

dan EnergiUniversitas Trisakti

1

CURRICULUM VITAE Name : Dr. Ir. Eko Widianto, MTPlace of Birth : Semarang, 3 September 1955Marital Status : MarriedAddress : Rancho Indah, Jl. Tanjung 19 / Blok G-21 Tanjung Barat, Jakarta Selatan 12530 Email : ewidianto@trisakti.ac.id

ewidianto@ymail.com

Education 1982 : Bachelor Degree in Geology of UGM 2000 : Magister Degree in Applied Geophysics of ITB

2008 : Doctoral Degree in Applied Geophysics of ITBWork History1982 – 1985 : Pertamina Exploration Division Jakarta1986 – 1993 : Pertamina Exploration Department Plaju1993 – 1994 : Pertamina BPPKA Jakarta1994 – 1997 : Head of Exploration Planning Jakarta1998 – 2000 : Exploration Manager JOB Pertamina – Greka Energy2000 – 2002 : Chief Geophysic Pertamina Upstream

President of Indonesian Association of Geophysicists (HAGI)2002 – 2006 : General Manager of JOB Pertamina-ConocoPhillips (Sakakemang) Ltd.2006 : Vice President of Pertamina Upstream New Venture Business Development2006 – 2007 : Board of Director of Joint Venture Pertamina – Petronas – Petro Vietnam2006 – 2008 : Vice President of EP Technology Center2009 – 2011 : Senior Geophysicist2011 – now : Lecturer of Geology Engineering of Trisakti Universty

Lecturer of Geophysic Engineering of Bandung Institute of Technology

Lecturer of Geology Engineering of Gadjahmada Universty 2

Pendahuluan Pada kuliah pertama, Dosen wajib memberitahukan:

a) Rencana Pembelajaran b) Daftar buku acuan (buku teks / referensi) yang digunakanc) Tata tertib Perkuliahan dan Sistem penilaian dan (serta)

pembobotan masing-masing komponen penilaian yang digunakan

d) Ada atau tidaknya kuis (ujian-ujian kecil)e) Tata tertib dan peraturan yang berlaku di Universitas Trisaktif) Bahaya penyalahgunaan Narkoba dan sanksinyag) Menunjuk salah seorang mahasiswa peserta mata kuliah

tersebut sebagai ketua kelas.

Ketentuan Pelaksanaan Kuliah, Asistensi / Responsi dan Praktikum

•Kuliah, Asistensi / Responsi dan Praktikum harus dilaksanakan tepat waktu sesuai dengan jadwal.

•Mahasiswa diwajibkan hadir mengikuti Kuliah, Asistensi / Responsi dan Praktikum sesuai dengan yang tercantum dalam Kartu Rencana Studi masing-masing. Kehadiran mahasiswa dicatat dalam daftar hadir mahasiswa.

Jika Dosen berhalangan,

sehingga kehadirannya tidak sesuai dengan ketentuan jadwal perkuliahan, maka Dosen tersebut wajib:a. Memberitahukan ketidakhadirannya kepada Subbag Perkuliahan

dan Ujian di Fakultas atau Sekretariat Program Studi.b. Menggantikan kuliahnya pada kesempatan yang lain atau diisi

dengan kegiatan yang sama oleh dosen pengganti.

•Mahasiswa wajib menunggu kehadiran dosen di kelas dalam waktu 15 menit. Apabila sesudah 15 menit ternyata dosen belum juga hadir tanpa pemberitahuan, maka ketua kelas melaporkan kepada Subbag Perkuliahan dan Ujian di Fakultas atau Sekretariat Program Studi. Apabila sudah ada kepastian bahwa dosen pengganti belum (tidak) ada, mahasiswa dapat meninggalkan ruang kuliah, setelah menandatangani daftar hadir.

Mahasiswa wajib menunggu kehadiran dosen di kelas dalam waktu 15 menit. Apabila sesudah 15 menit ternyata dosen belum juga hadir tanpa pemberitahuan, maka ketua kelas melaporkan kepada Subbag Perkuliahan dan Ujian di Fakultas atau Sekretariat Program Studi. Apabila sudah ada kepastian bahwa dosen pengganti belum (tidak) ada,

mahasiswa dapat meninggalkan ruang kuliah, setelah menandatangani daftar hadir.

Apabila Dosen melalaikan kewajiban-kewajiban tersebut di atas (memberikan kuliah kurang dari 70% tatap muka terjadwal dalam satu semester), pimpinan fakultas/Program Studi dapat memberikan teguran/peringatan dan sanksi mulai dari yang ringan sampai dengan yang berat (dalam bentuk pemberhentian).

3. Kehadiran Mahasiswa Dalam Perkuliahan

Mahasiswa diwajibkan hadir minimal 70 % dari jumlah tatap muka.Petugas administrasi perkuliahan akan menghitung jumlah kehadiran tiap mahasiswa yang digunakan sebagai prasyarat untuk dapat mengikuti Ujian Akhir Semester.

4. Kesetaraan jam perkuliahan dengan bobot sks.

Sesuai dengan ketentuan yang berlaku di Universitas Trisakti, maka tabel berikut memberi pedoman untuk mengatur jam masing-masing jenis perkuliahan dalam hubungannya dengan bobot sks mata kuliah yang bersangkutan dalam satu semester.

Komponen Rentang Nilai

% Bobot

Terstruktur: Tugas, Kuis, Makalah,

Presentasi dan Partisipasi Aktif di

kelas serta absensi kehadiran kuliah

0 –100 5 - 30 %

Ujian Tengah Semester (UTS) 0 – 100 20 - 40 %

Ujian Akhir Semester (UAS) 0 – 100 20 - 50 %

Absensi 10 %

Jumlah nilai dalam angka 100 %

Tabel :Pedoman Penentuan Bobot Penilaian

Keterangan :Dalam sistem SKS, komponen penilaian harus termasuk didalamnya tugas terstruktur.Untuk memperoleh nilai akhir maka jumlah nilai angka dikonversi menjadi nilai huruf.

Evaluasi Hasil Belajar (EHB)• Evaluasi hasil belajar dapat dilaksanakan dengan berbagai

cara ujian dan kegiatan terstruktur sesuai dengan jenis serta tingkat kompetensi yang dituntut dalam Kurikulum Operasional (KO).

• Macam-macam Evaluasi Hasil Belajar: a. Ujian terdiri dari:

– Ujian Tengah Semester (UTS)– Ujian Akhir Semester (UAS)– Ujian Komprehensif – Ujian Tugas Akhir

EHB lanjutan

b.Evaluasi kegiatan terstruktur Selain ujian-ujian tersebut di atas terdapat

kegiatan-kegiatan terstruktur lain yang berbentuk: 1). Penulisan karangan ilmiah/ makalah2). Pekerjaan rumah/ tugas/ kuis3). Partisipasi aktif dalam kelas 4). Presentasi dan sebagainya

Persyaratan peserta ujian:

» Terdaftar sebagai mahasiswa yang sah pada program studi

» Memenuhi jumlah kehadiran kuliah minimal 70 % dari jumlah seluruh perkuliahan atau jumlah tatap muka

» Membawa Kartu Peserta Ujian (KPU) / Kartu Rencana Studi (KRS) yang berlaku.

» Mentaati tata tertib ujian

LECTURE MATERIALS

1. INTRODUCTION (1X) a. Definitionb. Geophysical Methods and their main applicationsc. Level of Petroleum Investigation

2. REFLECTION SEISMIC (8X) a. Fundamental of Seismic Reflection Methodb. Acquisitionc. Processingd. Structural Interpretatione. Stratigraphic Interpretationf. Exercise g. Field Trip (if possible)

3. GRAVITY (3X) a. Introduction and general application of gravity datab. Gravity data analysis for Oil and Gas Explorationc. Paradigm Shift in Gravity data utilizationd. Gravity data analysis for Oil and Gas Reservoir Monitoring (Time lapse)

4. MAGNETIC (1X) a. General Application of Magnetic Data

PUSTAKA1. Abriel, William L.; 2008: Reservoir Geophysics:

Applications ; Distinguished Instructor Series, No. 11. SEG & EAGE.

2. Brown, 1998, Interpretation of 3-D Seismic Data.

3. Calvert, Rodney; 2008: Insights and Methods for Reservoir 4D Reservoir Monitoring and Characterization; Distinguished Instructor Series, No. 8. SEG & EAGE.

4. Dobrin, MB, 1980, Introduction to Geophysical Prospecting,2nd, McGraw-Hill Book Company.

5. Gibson, R. I. (1998): Gravity and Magnetics in Oil Exploration: A Historical Perspective, in Gibson, R.I., Millegan, P.S. Eds., Geologic Applications of Gravity and Magnetics: Case Histories; SEG Geophysical References Series, No 8, AAPG Studies in Geology, No. 43; Published Jointly by SEG and AAPG, Tulsa, USA.

6. Link, 1992, Basic Petroleum Geology.

PUSTAKA7. Magoon, L.B.; Dow, W.G., 1994: The Petroleum System – From

Source to Trap; AAPG Memoir 60; Tulsa, Oklahoma, USA.

8. McConnell, D., Steer, D., Knight, C., Owens, K., Park, L., 2008; The Good Earth; Mc Graw Hill.

9. Reynolds, John, M.; 1997; An Introduction to Applied and Environmental Geophysics; John Wiley and Sons Ltd.

10.Sharma, PV, 1990, Geophysical Methods in Geology, 2nd, Elsevier.

11.Sheriff, RE, 1995, Encyclopedic Dictionary of Exploration Geophysics, 3th ed, SEG.

12.Sheriff, R.E, Geldart, L.P., 1995; Exploration Seismology, 2nd Edition; Cambridge University Press.

13.Sheriff, R.E. (ed.); 1994; Reservoir Geophysics; Society of Exploration Geophysicists, Tulsa Oklahoma

14.Telford, WM., Geldart, LPm, Sherriff, RE., 1990, Applied Geophysics, 2nd ed, Cambridge University Press.

-1-INTRODUCTION

Definition

DEFINITIONS Geophysics:

The study of the earth by quantitative physical methods, especially by seismic reflection and refraction, gravity, magnetic, electrical, electromagnetic, and radioactivity methods (Sheriff, 1999).

To avoid of confusion, the use of physics to study the interior of the earth, from land surface to the inner core, is known as Solid Earth Geophysics. This can be subdivided further into Global Geophysics, which is the study of the whole or substantial parts of the planet, and Applied Geophysics which is concerned with investigating the Earth’s crust and near-surface to achieve a practical and, more often than not, an economic aim (Reynolds, 1997).

Geophysical Exploration / Geophysical Prospecting / Applied Geophysics:

Making and interpreting measurements of physical properties of the earth to determine subsurface conditions, usually with an economic objective, e.g., discovery of fuel or mineral deposits. Properties measured include seismic, gravity, magnetic, electric, and temperature (Sheriff, 1999).

Engineering Geophysics:

The application of Geophysical Methods to the investigation of sub-surface materials structures which are likely to have (significant) engineering application.

Environmental Geophysics:

As the range of application of geophysics methods has increase, particularly with respect to contaminated land investigation, the sub-discipline of “environmental geophysics” has developed (Greenhouse, 1991; Steeples, 1991), This can be defined as being:

“The application of geophysical methods to the investigation of near-surface physico-chemical phenomena which are likely to have (significant) implication for the management of the local environment”

-1-INTRODUCTION

Level of Petroleum Investigation

1st• SEDIMENTARY

BASIN

2nd• PETROLEUM SYSTEM

3rd• PLAY

4th• PROSPECT

Magoon and Dow (1994)

Four Levels of Petroleum Investigation

ECONOMICSNOT

IMPORTANT

ECONOMICSVERY

IMPORTANT

22

1st• SEDIMENTARY BASIN

2nd • PETROLEUM SYSTEM

3rd • EXPLORATION PLAY

4th • PROSPECT

5th • DELINEATION

6th • DEVELOPMENT

7th • PRODUCTION

Levels of Petroleum Investigation

EXPLORATION PHASE

DEVELOPMENT & PRODUCTION

PHASE

BasinReview

PetroleumSystem

Play Concept/Prospect

Geological and PetroleumGenerating Processes

Risk

Engineering

Volumetric

EconomicAnalysis

PostDrill

Review

Optimization

PETROLEUM SYSTEM IN THEEXPLORATION EVALUATION PROCESS

After Schneidermann & Robert M. Otis, IPA 1997

Sedimentary basins, petroleum systems, plays, and prospect can be view as separate levels of investigation, all of which are needed to better understand the genesis and habitat of hydrocarbons.

Sedimentary basin investigations emphasize the stratigraphic sequence and structural style of sedimentary rocks.

Petroleum system study describe the genetic relationship between a pod of active source rock and the resulting oil and gas accumulations.

Investigation of play describe the present-day geologic similarity of a series of present-day traps.

Study of prospects describe the individual present-day trap

If plate tectonics involves all phases of global geology, it follows that it directly influences petroleum geology. There is no field of petroleum geology that is not controlled by (or at least connected with) plate tectonic processes, including basin formation processes, certain sedimentation processes, the type of sediments present, and the thermal maturation of kerogen-thus, the entire history of oil and gas. For example: a petroleum geologist will ask "To what degree is a certain area a prospect for oil?" To arrive at a correct answer, he or she must first answer a number of individual questions:

FRONTIER BASIN ANALYSIS

Source Rock

Migration Route

Reservoir Rock

Seal Rock

Trap

Elements

Generation

Migration

Accumulation

Preservation

Processes

Petroleum System DefinitionGeologic components and processes necessary to generate and store hydrocarbons, including a mature source rock, migration pathway, reservoir rock, trap and seal. Appropriate relative timing of formation of these elements and the processes of generation, migration and accumulation are necessary for hydrocarbons to accumulate and be preserved. The components and critical timing relationships of a petroleum system can be displayed in a chart that shows geologic time along the horizontal axis and the petroleum system elements along the vertical axis. Exploration plays and prospects are typically developed in basins or regions in which a complete petroleum system has some likelihood of existing.

Prospect - a lead which has been fully evaluated and is ready to drill

Play - A particular combination of reservoir, seal, source and trap associated with proven hydrocarbon accumulationsLead - a structure which may contain hydrocarbons

Exploration Play - Lead - Prospect

Factor Sedimentary Basin

Petroleum System

Play Prospect

Investigation

Economics

Geologic Time

Existence

Cost

Analysis & Modeling

Sedimentary Rock

None

Time of deposition

Absolute

Very Low

Basin

Petroleum

None

Critical Moment

Absolute

Low

System

Traps

Essential

Present-day

Conditional

High

High

Trap

Essential

Present-day

Conditional

Very high

Prospect

Factor Comparison in the Four Levels of Petroleum Investigation

Magoon and Dow (1994)

-1-INTRODUCTION

Geophysical MethodsAnd Applications

Define the oil and gas resources in the entire

basin of IndonesiaProve the resources to be

reservesBuild reservoir model

accuratelyMonitor and image the dynamic properties of

reservoir until field termination

Optimize production

Improve Recovery Factor

How we can

Exploration and Development Challenges

30

How can we double the production and still have bigger reserve than we started with?

High Technology

PROBLEM STATEMENT

31

What role of exploration geophysics to oil and gas exploration

and development?

Frequently used of geophysical methods for surface recording and typical applicationGeophysical method

Physical property measured

Typical applications Comment on applicability

Seismology Seismic wave velocity, seismic impedance contrast, attenuation, anisotropy

Delineation of stratigraphy and structures in petroleum exploration

Exploration seismology is the most widely used geophysical method in petroleum exploration.

Gravity Surveys Rock density contrast Reconnaissance of large-scale density anomalies in petroleum and mineral exploration

Gravity survey are generally less expensive but have less resolving power than seismic exploration.

Magnetic Surveys Magnetic susceptibility or the rock’s intrinsic magnetization

Reconnaissance of the crustal magnetic properties, especially for determination of basement features

Aeromagnetic surveys are widely used in both petroleum and mining application for determining large, deep structure.

Electrical and electromagnetic surveys

Rock resistivity, capacitance, and inductance properties

Mineral exploration These methods are used most frequently in mining exploration and well logging (resistivity, SP, and induction log)

(Lines and Newrick, 2004)

Geophysical methods

Dependent Physical Property

Applications (see key below)

1 2 3 4 5 6 7 8 9 10

Gravity Density P P S S S S U U S U

Magnetic Susceptibility P P P S U M U P P U

Seismic Refraction Elastic Moduli, density P P M P S S U U U U

Seismic Reflection Elastic Moduli, density P P M S S M U U U U

Resistivity Resistivity M M P P P P P S P M

Spontaneous Potential Potential differences U U P M P M M M U U

Induced Polarization Resistivity, capacitance M M P M S M M M M M

Electromagnetic (EM) Conductance, inductance S P P P P P P P P M

EM - VLF Conductance, inductance M M P M S S S M M U

EM – Ground Penetrating Radar

Permitivity, conductivityU U M P P P S P P P

Magneto-telluric Resistivity S P P M M U U U U U

GEOPHYSICAL METHODS AND THEIR MAIN APPLICATIONS

P= primary method; S=secondary method; U=unsuitableM=may be used but not necessarily the best approach, or has not been developed for this application

(Reynolds, 1997)

Applications:1 Hydrocarbon exploration (coal, gas, oil)2 Regional Geological study (over areas of 100s of km2)3 Exploration/development of mineral deposit4 Engineering site investigations5 Hydrogeological investigations

6 Detection of sub-surface cavities7 Mapping of leachate and contaminant plumes8 Location and definition of buried metallic objects9 Archaeological geophysics10 Forensic geophysics

Project phase

Critical subsurface information

Technology Involvement

1) Exploration Proven Petroleum System and Play Resources information

Geophysics Geology Concept Drilling

2) Delineation Total hydrocarbon volume Areal limits of petroleum reservoir Deliverability

Geophysics Geology Concept Drilling Reservoir

3) Development

Compartmentalization Exact locations of development wells

Geophysics Development Geology Drilling Reservoir

4) Production Hydrocarbon saturation and pressure changes Flow restrictions and channeling

Production Reservoir Geophysics

Oil and gas operational phases and Technology Involvement

36

1• Regional Study

2• Leads and Prospect Generation

3• Drillable Prospect Generation

4• Drilling

5• Plan of Development

6• Reservoir Monitoring

1• Gravity, Magnetic, 2D Seismic

2• 2D or 3D Seismic

3• 2D or 3D Seismic

4• Borehole Seismic

(Checkshot, VSP)

5• 3D Seismic Reflection,

Resistivity

6• Time lapse Geophysics

(4D Gravity, 4D Seismic)

Paradigm Shift of Gravity Technology Application For Oil and Gas IndustryStages Geophysical Tools

TECHNOLOGY APPLICATION IN OIL AND GAS INDUSTRY

Stages in Geophysical Technology Application for

Subsurface Mapping

Data Acquisition

Data Processing

Data Interpretation

Geophysical Subsurface Model

Survey Design

THANK YOU