002 course slides

8/8/2019 002 Course Slides

1/23

Geophysicist

Basic tools:

Magnetic surveys Gravity surveys Seismic surveys

Surface - land or marine

Borehole

Interpretation of data in 2D, 3D and 4D :

Provides structural information on the large scale Seismic bright spots indicate potential hydrocarbons Field wide data

Plan and QC seismic acquisition program


2/23

rinciples of Seismic

Reflection of of acoustic energy by sub surface boundaries


3/23

2D Seismic

Structure

Line spacing = 500 m - 2 km


4/23

D Section - Stacked and Migrated

Potential Hydrocarbon

Trap


5/23

3D Seismic Concept

Crossline >

Inline

>

Parallel grid pattern shoot

25m spacing


6/23

D Cube for Interpretation


7/23

eismic-Well Ties

Initial Synthetic-Seismic TieInitial SyntheticInitial Synthetic--Seismic TieSeismic Tie

Final Synthetic-SeisFinal SyntheticFinal Synthetic--SeisSeis


8/23

Surface

sourceSurface

geophone

Weatheredlayer

Boreholegeophone

Reservoirunit Borehole

source

1-Crosswell

2-VSP3-Reverse VSP4-Surface5-Single well

43

2

1

5

Borehole Seismic

D Ti l S i i


9/23

4D Time lapse Seismic


10/23

ec no ogy s xpec e o


11/23

Before 1980:2-D 25-30%of oil recovered

1980-95:3-D 40-50%recovered

SlicesVolumes

*BP/Shells estimate,

Petroleum Engineer International; January, 1996.

1996 - future:4-D 65-75%recovery*

Changes

- ec no ogy s xpec e oImprove Recovery

G l i


12/23

Geologist

Basic tools:

Rock Samples - Outcrops, Cores, Well Cuttings Well Log Data - LWD or Wireline Borehole Image Logs & Dip Meters Fossils and Palynology

Interpret all available data to provide : Geological Dating Sequence Stratigraphy Depositional Environment Sedimentology

Geological Structure Rock Mecanics and In Situ Stress

Plan and QC Coring Program

h i f S di E i


13/23

AlluvialFans

LakeDelta

Lake

Exaggeratedvertical scale

TurbiditeChannels

ContinentalSlope

ContinentalShelf

Coastal

Continental

MeanderingStream

Delta

BraidedStream

DesertDunesBay

Beach

BarrierIsland

TidalShoals

DeepSeaFan

Bigelow et al.,1987

chematic of Sedimentary Environments

lk d l 1978


14/23

Feeder Channel

Slope into Basin

Lower Fan

Debris

Flows

D-B

CGLS.

Slumps

Upper

Fan

Massive ssts.Pebbly ssts.

Thin bedded turbiditeson levee

Thin bedded

Mid Fan

Classical turbidites

Graded-stratified

Graded-bed

Conglomerates:Inverse-to normallly

gradedTerrace

Proximal

New suprafanlobe

Incisedchannel

Braided

Supra Fan Lobes

Basin

Plain No relative scale implied

alker model, 1978

t t l U t i ti


15/23

tructural Uncertainties

Structural Dip Determination

Where to drill well to have as good or

better structural position

Fault Identification and Analysis

Determine strike and dip of the fault

Determine rock displacement along

the fault Fracture Identification and

Characterization

Closed or open , Natural or drillinginduced

Orientation, spacing, frequency

Characterization of In-Situ Stresses

Optimal borehole stability

Drilling induced fractures

Potential & artificial fracturing

1 Km.

-7720

G l i l M d l


16/23

Geological Model

Petrophysicist


17/23

Petrophysicist

Basic tools:

Borehole Logging Tools (LWD or Wireline) :

Caliper

Gamma Ray

Resistivity

Density and Neutron

Acoustics NMR

Formation Test

Core Data

Interpret well log data to provide Matrix type Fluid Types & Pressure Gradients Fluid Saturations & Volumes Porosity & Permeability

Plan and QC logging programs


18/23

GR

GAPI0 150

BS

IN6 16

VSH

V/V0 1

BADHOLE

0.5 0

4600

4700

4800

DEPTH

F E E T

RP2000

0.2 200

RP400

0.2 200

RA400

0.2 200

RHOB

G/C31.66 2.65

NPHI

V/V0.6 0

PHIT

V/V0.6 0

PHIE

V/V0.6 0

VOL

V/V1 0

PHIE

V/V1 0

PHIT

V/V1 0

MATRIX

0 1

Reservoir Engineer


19/23

Reservoir Engineer

Basic tools:

Well Test / Production Data - Pressure, Temperature, Rates Fluid Samples Core

Interpret all available data to provide :

Rock Properties - permeability, capillary pressure, wettability Fluid Properties - viscosity , compressibility Fluid Behaviour - relative permeability Reservoir Properties - pressure, volume, temperature,

- permeability & skin

Reservoir Model - recoverable reserves, productivity Reservoir Simulation - Production scenarios

Plan and QC Well Test and PVT Tests

Plan and monitor production

Reservoir Engineer


20/23

Reservoir Engineer

Surface Separator

Water

Oil

Gas

Bottom Hole Sample

(at reservoir conditions)

Surface Sample

Reservoir

Borehole

Well Test :

Take : Fluid Samples

Measure : Flow Rates (bbl/day)

Pressure and Temperature

Derive : Productivity (bbl/day/psi)

Near Well Conditions (skin)

Reservoir Conditions (permeability)

Boundary Conditions (Tested Volume)

Reservoir Engineer


21/23

Reservoir Engineer

Bottom Hole Sample

Surface Sample

PVT

Analysis

Reservoir Engineer


22/23

Reservoir Engineer

Reservoir Simulation Model :

Predict production v time Predict drainage patterns Predict onset of water cut and / or gas breakthrough Determine optimum recovery techniques

primary = natural flow

secondary = pumping or pressure maintenance tertiary = alteration of reservoir conditions

eg steam (temp), chemical (viscosity)

Reservoir Engineer


23/23

Reservoir Engineer

Time

Productio

n

bbl/day Plateau

Decline Curve

Constrained by :

No. wells, Surface Facilities,

Contracts, Critical Rates, etc.

Affected by :

Total Reserves, Recovery mechanism Reservoir Complexity

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