SPE DISTINGUISHED LECTURER SERIESis funded principally

through a grant of the

SPE FOUNDATIONThe Society gratefully acknowledges

those companies that support the programby allowing their professionals

to participate as Lecturers.

And special thanks to The American Institute of Mining, Metallurgical,and Petroleum Engineers (AIME) for their contribution to the program.

Formation Testing: Where Are We After 15 Years with

Advanced Wireline Tools?

Pressures

Sampling and Downhole Fluid Analysis

Transient Testing (IPTT)

In-Situ Stress Testing

Cosan AyanCosan AyanSchlumberger Reservoir Engineering AdvisorSchlumberger Reservoir Engineering Advisor

Formation testing-evolution

Early formation testers: circa 1956

Latest formation testers~1991 onwards

Several service companies have a variety of tools

• Various probe assemblies, combination of probes• Dual inflatable packers• Downhole pumpout capability• Several sample chambers• Fluid identification modules• Capability to work in cased hole

Formation Testing: Where Are We After 15 Years with Advanced Wireline Tools?

Pressures

Sampling and Downhole Fluid Analysis

Transient Testing (IPTT)

In-Situ Stress Testing

Pressure test: example-1

Pretest 5cc @ 2cc/sec

Mobility=75 md/cpPr

essu

re, p

sia

Time, sec

Pressure testing in very tight zones x550

x650

x750

x850

x950

y050

y1502900 2950 3000 3050 3100 3150

Formation Pressure, (psi)

Dep

th S

. S. (

ft)

WL-1 Single Probe

WL-2 Dual packer

Flow area of packer is significantly large compared to probe

Dual packer type devices have increased flow area compared to a probe.

Formation Testing: Where Are We After 15 Years with Advanced Wireline Tools?

Pressures

Sampling and Downhole Fluid Analysis

Transient Testing (IPTT)

In-Situ Stress Testing

Sampling and downhole fluid analysis

Good samples and fluid analysis depend on:

•Reduced mud filtrate contamination

•Reduced drawdown during sampling to stay above phase separation envelopes

•Keeping samples above the phase separation envelopes at surface conditions

Filtrate cleanup for probe type testers

0.16

0.18

0.2

0.22

0.24

0.6

0.65

0.7

0.75

0.8

0.85

0.9

500 1000 1500 2000 2500

ODOD

Methane

Pumping Time (sec)

Log 7.0% Lab 5.5%

8%

Methane

Color

6%

OBM Contamination

0.16

0.18

0.2

0.22

0.24

0.6

0.65

0.7

0.75

0.8

0.85

0.9

500 1000 1500 2000 2500

ODOD

Methane

Pumping Time (sec)

Log 7.0% Lab 5.5%

8%

Methane

Color

6%

OBM Contamination

filtr

ate

filtr

ate

OilFiltrate

Filtrate dumped into borehole

Oil flow

Oil zone

Phase separation envelopes

0

2000

4000

6000

8000

10000

0 100 200 300 400 500Temperature (F)

Pres

sure

(psi

a)

Hydrate Envelope

Gas Envelope

Wax Envelope

Asphaltene Envelope

Advanced samplers are now available to keep the samples above phase separation pressure(s)

Emulsion StabilityFoaming Heavy Oil

Wax

Asphaltene

GasHydrate

Diamondoids

Organic Scale

Tar Sand Extraction

AthabascaBitumen

Oil chemistry and flow assurance

Oil Chemistry has Huge Impact in‘Typical’ Production.

Downhole fluid analysisCurrent formation testers can give a few downhole fluid properties at each test point:

•Gas Oil Ratio: 200 to 20,000 scf/stb (black oils to retrograde gas condensates)

•Fluid composition (wt % of certain components)

•Free gas and liquid dew detection

•Mud filtrate contamination (vol %)

•Water phase pH

•H2S ?

Fluid Gradients from BiodegradationLiaohe Basin turbiditic sandstones of Eocene age at 1.8km depth. Tr ~ 65oC

Prof. S.R. Larter, U. Newcastle on Tyne

Factor of 7 Variation in Viscosity 130 Meters

Saturated HC (%)

30 70

PhytaneN-octadecane

1 51700

1800

1700

1800

met

ers

me t

e rs

Fujisawa, Betancourt, Mullins, Torgersen, O’Keefe, Dong, K.O. Eriksen, SPE #89704, ATCE, (2004)

Reservoir fluid gradient Statoil, North Sea

Pressure vs Depth

0.374 g/cc

0.599 g/cc

0.982 g/cc

xx60

xx80

xx00

xx20377 378 379 380 381

Pressure (bar)

Dep

th (m

)

C2-C5C1 C6+ water9000xx68.2m

2500xx75.1m

xx85.6m 21001800xx00.0m

xx06.3m 1500

GOR(scf/bbl)

Composition (wt%)

Uniform Oil Properties

Oil Comp. Gradients

3500

3000

2500

2000

1500

GOR

Reservoir Modeling: composition gradients

Optimize production strategy on right model.Size facilities properly.Manage production below bubble point.Understand time evolution..

Actual Oil Color

x973ft

x040ft

x057ft

x065ft

OtherGases

HCLiquids

No gas here.

Phase behavior time evolutionseen in oil color. Heavy end reduction with more gas.

Gas Here.

Downhole fluid analysis in production setting

Miscible Injection project and changing fluids

CH4

Downhole vs. lab results Fluorescence

Downhole, Lab Mostly agreeBut problem here.

Color channels

C6+C2-C5 group

CH4

GOR (scf/bbl)(Downhole : Lab)

xx339.1 ft (20,400 : 26,000)

xx386.9 ft (4,500 : 5,000)

xx433.0 ft (1,600 : 930)

xx687.3 ft (1,500 : 1,400)

Formation tester downhole pH determination

pH > 9 base only6 <pH < 9

acid-base mixture

pH < 6acid only

pH Sensitive Dye

1.2

1.0

0.8

0.6

0.4

0.2

0.0

OD

700600500400

Wavelength (nm)

0.8

0.6

0.4

0.2

0.0

OD

700600500400

Wavelength (nm)

experimentpredicted

pH=7.4

AB

1.2

1.0

0.8

0.6

0.4

0.2

0.0

OD

700600500400

Wavelength (nm)

Accuracy ~ 0.1 unitRange pH = 4 to 9

Downhole water analysis:early understanding of scale problems

LAB pH: Lost gas, solids. ∆pH ~ +/-1

0

1

2

3

4

5

6

0 2000 4000 6000 8000 10000 12000

Time (s)

Opt

ical

Den

sity

0

10

20

30

40

50

60

70

80

90

100

Ch1(s)Ch2(s)Cont(Ch1)Cont(Ch2)

Filling the 1 gallon sample chamber

Filling the multisample bottles

Opt

ical

Den

sity

Time

Decreasing

Blue dyeC

ontamination

Real time WBM contamination

0

100

10

90

Water sampling in WBMSPE 88637-North Sea

Formation Testing: Where Are We After 15 Years with Advanced Wireline Tools?

Pressures

Sampling and Downhole Fluid Analysis

Transient Testing (IPTT)

In-Situ Stress Testing

Permeability and permeability anisotropy

Interval Pressure Transient Tests (IPTT) are conducted with various combinations of probes and/or dual packer.

Objective is to obtain permeability and anisotropy in “10’s” of feet around the well.

Transient testing-carbonates

1e+03∆time, sec

1e 00

Pres

sure

and

Der

ivat

ive,

psi

1e+02

1e+03Pressure changePressure derivative

Pressure changePressure derivative

Ce1

1e+02

1e+01

1e 00

1e-01

1e-021e+011e-01

2

Transient testing-loose sand

1e-01

1e+00

1e+01

1e+02

[Del

ta P

]/[D

elta

q] (

psi)/

(bbl

/d)

PressureDerivative

1e-01 1e+00 1e+01 1e+02 1e+03Delta T (s)

1e-02

∆time, sec1e+031e+011e 001e-01 1e+02

Nor

mal

ized

Pre

ssur

e an

d D

eriv

ativ

e,

psi

Pressure and Derivative, psi/rb/d

Comparative diagnostic plot

Kh =~ kv= 1000 md(loose sand, 100 cp oil)

Gulf of MexicoFormation tester-transient testing (OBM)

Main VIT -Probe 1

dp&

dp’

Nor

mal

ized

by

Rat

e

Delta time (hours)

1E-5 1E-4 1E-3 0.01 0.1 11

10

100

BU PretestVIT Build Up (ref)build-up #8

Rate normalized pressure and derivatives

Dual Packer

Vertical probe-1

Nor

mal

ized

Pre

ssur

e an

d D

eriv

ativ

e, p

si

10.001 0.01 0.1 100.0001

Formation tester IPTT and DST-Brasil

Analysis of individual IPTT’s

Formation Testing: Where Are We After 15 Years with Advanced Wireline Tools?

Pressures

Sampling and Downhole Fluid Analysis

Transient Testing (IPTT)

In-Situ Stress Testing

In situ stress testing (micro fracturing)

Mostly Conducted using packer type formation testers

In-situ stress testing Magnitude and orientation

Formation Testing: ConclusionsWhere Are We After 15 Years with Advanced Wireline Tools?

Pressure measurements: Moving towards tighter rockswith faster surveys and now possible behind casing

Sampling and Fluids: Sampling techniques/stringsgetting very complex. Fluid analysis is moving downhole

Transient Testing (IPTT): Tests investigating 10’s of feet, capturing anisotropy and heterogeneity

In-Situ Stress Testing: Micro-fracturing to get stress magnitude