Chapter 3 Petroleum Prospecting ()

Referencesfor (Petroleum Prospecting)

Textbook 1 Fundamentals of Petroleum, Petroleum Extension Service, The University of Texas at Austin, Austin, Texas,1979. chapter 2

Textbook 4 Hyne,N.J., Petroleum Geology, Exploration, Drilling and Production, Penn Well Co., Tulsa, Oklahoma, 2001. -- chapter 13 ; 14 (p. 195-232)

Textbook 1 chapter 2 SPE Energy Education

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*Text BooksTextbook 1 Fundamentals of Petroleum, Petroleum Extension Service, The University of Texas at Austin, Austin, Texas,1979.

Textbook 2 Archer, J. S., and Wall, C.G., Petroleum Engineeringprinciples and practice, Graham & Trotman, MD, 1986. TextBook 3 Donohue, D.A.T., and Lang K.R., Petroleum Technology, International Human Resources Development Corporation, Houston,1986. Textbook 4 Hyne,N.J., Petroleum Geology, Exploration, Drilling and Production, Penn Well Co., Tulsa, Oklahoma, 2001.

Textbook 5 Devereux, S., Drilling Technology, Penn Well Co., Tulsa, Oklahoma, 1999.

* 1. (Introduction) Textbook 2 chapter 1 Textbook 4 chapter 1

2. (Petroleum Geology and Reservoir) Textbook 1 chapter 1 Textbook 2 chapter 2 Textbook 3 chapter 4.1; 4.2

3. (Petroleum Prospecting) Textbook 1 chapter 2 Textbook 4-- chapter 13 ; 14

SPE Energy Education

4. (Drilling Engineering) Textbook 1 chapter 4 Textbook 2 chapter 3 SPE Energy Education Textbook 3 chapter 1

Chapter 3 Petroleum Prospecting()(Surface observation) by observation on earth surface

(Geological exploration) downward projection of geologic information

(Geochemical exploration) --tracing hydrocarbons in soil and water (Geophysical exploration) physical measurements of gravity, magnetic and seismic of subsurface

()

(Surface Observation) () seeps (plate 13-1, 13-2, and fig. 13-1)

--Seeps

-- Seeps

(plate 13-3)

(fig. 13-2)

(fig 13-3; 13-4; 13-5; 13-6; 13-7)

(plate 13-3)

, (fig. 13-2)

--Marker bed (fig 13-3)

(Well logs)Marker bed(fig 13-6)

--Well logsMarker bed(fig 13-5)

-- (Microfossils)(fig 13-4)

-- (fig 13-7)

Geochemical explorationGeochemistry is the application of chemistry to the study of the earth.

Geochemistry can be used to trace hydrocarbons in soil and water indicating of the proximity of a petroleum trap.

Geochemistry can also be used to identify the source rock for a specific crude oil. The crude oils in traps can then be correlated with source rocks to determine the migration path for the petroleum.

to trace hydrocarbons Traces of hydrocarbons in soil and water are often good indications of the proximity of a petroleum trap (fig. 13-8). -- microseeps -- hydrocarbon halo() -- sniffers() -- Vitrenite reflectance

to trace hydrocarbons

Vitrenite reflectance

Play

A play is a combination of trap, reservoir rock, and seal that has been shown by previous discovered fields to contain commercial petroleum deposits in an area.

Trend A trend or fairway is the area along which the play has been proven, and more field could be found. (fig 13-9).

Prospect -- definition

A prospect is the exact location where the geological and economic conditions are favorable for drilling an exploratory well.

Prospect -- geological factorsThere are four major geological factors in the success of a particular prospect.

(1) There must have been a source rock that generated petroleum.

(2) There must have been a reservoir rock to hold the petroleum.

(3) There must be a trap. This includes a reservoir rock configuration that has four-sided closure, a seal on the reservoir rock, and no breach of the trap.

(4) The timing must be right. The trap had to be in position before the petroleum migrated the area.

Prospect - economicAn economic analysis of the prospect should include reserves and risk calculations.

(a)

(b)

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(a)()Gravity method(b)()Magnetic method(c)()Seismic method

(a)()Electrical method(b)()Radioactive method(c)()Well logging

()(Gravity Method)

(1)The gravity pendulum() ()

(2)The gravimeter() Hocks law,

(3)The Hoyt gravimeter (4)The astatized gravimeter

(3)The Hoyt gravimeter (4)The astatized gravimeter

()

()

(magnetic method) (a)-(b)-(c)-permeability

(B) & (H)

B=HFlux=permfield strength

=

()

(1)the permeability ()(2)the magnetization()

(magnetite)(); ( susceptibility),k,k

(Dome or anticline)

/ (Fault)

(Seismic Exploration)

(Seismic Exploration)

-- (Seismic reflection method)

-- (Seismic refraction method)

(Seismic reflection method)

Data Acquisition

Data Processing

Data Interpretation

(Data acquisition)

() (Data processing)

(Data interpretation) (Anticliness) (Syncliness) (Faults) (Pinchouts)

Data Acquisition

(Data acquisition)

()

(Data acquisition)

()

Vibrator Truck

Geophone

Air gun streammer

Data Processing

(Data processing)

(Bright spot)

Data Interpretation

Seismic Profile (correlating with drilling data)

(Salt dome)

(Isochron map)

(Structure map)

() ()( )

()Well Logging

(1)The Spontaneous-Potential (SP) Logs(2)Conventional Resistivity Logs(3)Focusing-Electrode Logs(4)Induction Logs(5)Microresistivity Logs(6)Sonic Logs(7)Formation density Logs(8)Neutron Logs(9)Gamma Ray Logs(10)

(Stratigraphy)(Rock Strata) --- (Origin) --- (Composition) --- (Distribution) --- (Succession)

(Stratigraphic test, or strata test)

(Stratigraphic correlation) -- (Strata) -- (fossils) --- (Rock hardness or softness) --- (Electric data)

It is much easier to correlate wells because the data that are collected by drillers logs, sample logs, electrical logsenable the geologists to predict more precisely where similar rock formations will occur in each case

Subsurface correlationIt is based primarily on stratigraphic continuity, or the fact that formations maintain the same thickness from one well to another.Any change in thickness can be a geologic indicator of a change in the conditions that formed the strata, or may be a signal of an event that could cause petroleum to accumulate.

Structure Map

Oil and gas discoveries

1842The presence of oil seep on anticline crests was observed1859The drilling of the famous Drake well in Pennsylvania1885I.C. White applied geological knowledge in search of gas in Pennsylvania and nearby states.Late 19tcenturyGeologist searched for oil in East Indians and Mexico1897Geological departments were established by some U.S. oil companies, Many of subsequent discoveries in the mid continent, Gulf Coast, California, and elsewhere were made with the application of geology to the problem of finding petroleum reservoir.

Gravity measurementsSeismic refractionSeismic reflection1915&1916The torsion balance was employed to detail the structure in a oil field at Egbell, now in Czechoslovakia()1919Ludger Mintrop applied for a German patent on locating and measuring depth to subsurface features by refraction.1919~1921The earliest experiments with the seismic reflection method were carried out by J.C. Karcher in central Oklahoma.1917Schweidar detailed a known salt dome at Hanigsen in Germany with a torsion balance and the predicted structure was confirmed by subsequent drilling1923The earliest work was in Mexico, but later in the year a refraction survey was under takan along the Mexico fault zone in the Texac Gulf coast. 1924The first oil discovery1922Shell surveyed the Horgada field in Egypt with a torsion balance1924Finding the orchard dome in Texas1927The reflection method was put to work for routine explorationLate1922The Spindletop field in Texas was traversed by a torsion balance yielding a strike anomaly over the known salt structure1928The seismic refraction method was introduced into the middle East by the Darcy Exploration Company (British Petroleum)1930By the early 1930s

Reflection become the most widely used of all geophysical techniques, a status has maintained ever since.1922The torsion balance was used for the first time to explore for oil over areas where the structure was completely unknown. This was in the Gulf coast of the U.S.A.1924Discovered the productive Nash dome in Texas.

wiggle trace

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