OIL & GAS MATURATIONGEOLOGY OFOIL AND GAS

ZULFIAHMUH. NAHRY FAUZANABD. HAFIDZANUGRAH DWINAL

PETROLEUM SYSTEM

Source rock

Migration

Reservoir rock

Trap

Seal

OIL & GAS MATURATION

Terjadi dalam atau dekat reservior pada waktu atau setelah migrasi primer selesai, dan terdiri dari suatu urutan perubahan diagenesa yang menghasilkan hidrokarbon dari senyawa yang lebih berat dengan molekul rendah

Berkaitan dengan:a. Suhub. Tekananc. Kedalaman d. waktu

Kematangan:a. Immatureb. Early mature for Oilc. Mid-mature for Oild. Late mature for Oile. Generation of Gas

OIL & GAS MATURATION

ZONE I BIOHEMICAL METANE GENERATION

DRY GAS

ZONE IIINITIAL THERMOCHEMICAL GENERATION

NO EFFECTIVE OIL RELASE

DRY GAS-WET GAS-CONDESATE-(OIL ?)

ZONE IIIMAIN PHASE OF MATURE OIL GENERATION AND RELEASE

OIL AND GAS

ZONE IVTHERMAL DEGRADATION OF HEAVY HIDROCARBON

(OIL PHASE-OUT)

CONDESATE WET GAS-DRY GAS

ZONE V INTENSE ORGANIC METAMORFISM: METANA FORMATION

DRY GAS

HC MATURITY ZONE,BISSADA (1986)

Carbon – Ratio

Fraksi Minyak dalam Batuan

Berat Jenis, Umur, dan Kedalaman

Konsepsi Pematangan Phillipi (1965)

OIL & GAS MATURATION PROCESSES

OIL MATURITYIDENTIFICATIONS

A. Vitrinite Reflectance analitionVITRINITE

REFLECTANCE

HYDROKARBON TYPE

0,33-0,35

0,35-0,66

0,60-0,80

0,80-1,30

1,30-1,60

1,60-2,00

> 2,00

Biogenic gas

Biogenic gas and oil immature

Immature oil

Mature oil

Mature oil, condesat, wet gas

Condesat, wet gas

Petrogenoic methane gas

OIL MATURITYIDENTIFICATIONS

SCI PALYNOMORPH COLOUR MATURITY DEGREE

1

2

3

4

5

6

7

8

9

10

Pale Yellow

Yellow

Yellow

Gold Yellow

Orange to Yeloow

Orange

Brown

Dark Brown

Drak Brown to Black

Black

Immature

Immature

Transition to mature

Transition to mature

Mature

Optimum oil generation

Optimum oil generation

Mature, gas condensat

Over mature, dry gas

Over mature, dry gas (traces)

B. Spora color index analition

C. Indeks Pengubahan Thermal

OIL MATURITYIDENTIFICATIONS

D. Tmax Pyrolisys analition

S1 / (S1= S2)

(mg/gr atau kg/ton)

Tingkat Kematangan

< 0,1

0,1-0,4

>0,4

Belum matang

Matang (oil window)

Lewat matang (gas window)

T Max (0 C) Tingkat Kematangan

400-435

435-460

>460

Belum matang

Matang (oil window)

Lewat matang (gas window)S1+S2

(mg/gr atau kg/ton)

Tingkat Kematangan

0,00-1,00

1,00-2,00

2,00-6,00

6,00-10,0

10,0-20,0

>20,0

Poor

Marginal

Moderate

Good

Very good

excellent

Incipient Oil Generation

Max. Oil Generated

Oil Floor

Wet Gas Floor

Dry Gas Floor

Max. Dry GasGenerated

(modified from Foster and Beaumont, 1991, after Dow and O’Conner, 1982)

Vit

rin

ite R

efl

ecta

nce (

Ro)

%

Weig

ht

% C

arb

on

in

Kero

gen

Sp

ore

Co

lora

tio

n In

dex (

SC

I)

Pyro

lys

is T

(C)

max

0.2

0.3

0.4

0.5

4.0

3.0

2.0

1.3

1

2

3

4

56

789

10

430

450

465

65

70

75

80

85

90

95

0.60.70.80.91.01.2

OIL

WetGas

DryGas

OIL MATURITYIDENTIFICATIONS

THANK YOU FOR YOUR ATTENTIONS