A New Multi Laterolog Tool For

Improved Petrophysical Models

SPE paper originally presented at MEOS 2011, Bahrain

Comparison of a New Multi Laterolog and a Formation Resistivity Imager T. Abdel-Shafy, A. Fattah, Khalda Petroleum Company,

M. Boudjatit, B. Corley, R. Khokhar, H. Maurer, Baker Hughes

SPWLA-Kuwait Chapter 4th presentation 2012

Thomas Glowig Geoscience Advisor

Baker Hughes Geoscience, KSA

Outline

Multi Laterolog wireline service (Rt eXplorer TM)

Phiops Field in Egypt

Well Data

Conclusions

Multi Laterolog (RTeX) Highlights

Four hardware focused curves with increasing depth of investigation.

One foot vertical resolution.

One piece construction (operational benefits)

–Mandrel and electronics in one housing.

–Does not require bridle (no remote return)

Eliminates Groningen effect

Model based adaptive borehole correction (ABC)

– Borehole corrected curves reflect true invasion profile

–Correction for varying tool positions in bore hole

–Real time Rt, Rxo and Lxo

Rt eXplorer (RTeX), fully combinable

Dimensions, weight /length

208 lb (94.35 kg) / 14.0 ft (4.24 m)

Depth of investigation

Up to 74-in. (188 cm) Rt/Rxo = 10/1

Typical ca. 40 inches

Vertical resolution

1 ft (30.3 cm)

Operational envelope

0.2–100,000 ohm-m (Rm = 1)

Maximum pressure / temperature

20,000 psi (1,380 Mpa) / 350°F (175°C)

Minimal borehole size

5.25 in. (13.3 cm)

Logging speed

3,600 ft/hr (1,097 m/hr)

RTeX schematic configuration

Electrodes A0 - A3 on the tool mandrel.

Other tool housings become electrodes A4 and A5.

This configuration allows to reduce the total overall tool string length and still achieve a deep measurement.

Monitor electrodes are used to control zero-potentail between guard electrodes

Multi Laterolog operating modes

Current stream lines and electric-potential patterns for each operating mode of Multi Laterolog in a formation

where: Bhd = 8 in; Rm=1 ohm-m and Rt = 10 ohm-m.

MLR1: 105Hz MLR2: 195Hz MLR3: 165Hz MLR4: 30Hz

Adaptive Borehole Correction (ABC)

raw measurement, model based inversion, final ABC corrected curves

10 m layer

Rt=300,

Rxo=15

ohm-m

3 m layer

Rt=300,

Rxo=15

ohm-m

Adaptive Borehole Correction

Adaptive Borehole Correction inverts tool response to an earth model of Rt, Rxo, Lxo and then transfers the tool response from a borehole with “real” mud resistivity, Rm to a response in a borehole with “virtual” mud resistivity equal to Rt (or Rxo)

Phiops Field

Jurassic to Lower Cretaceous ; Shushan Basin; South Umbarka concession, Western Desert, Egypt,

Location of the Phiops wells

Phiops-7

Phiops-6X Phiops-8

Phiops-4

Phiops-5

Phiops-1X

Phiops-2X

Well PHIOPS-7

Drilled December 2009

Total Depth 3890 m (12,750 ft)

Net Pay 14 m (45 ft)

Drill Bit 0.311 m (12 ¼ inches)

Mud Resistivity (at bottom hole temperature) 0.029 Ωm

Washed Out (shale sections) up to 0.4 m (16 inches)

Derived Length of Invasion 0.38 m (15 inches)

Derived True Formation resistivity 1.5 times higher than MLR4

Multi Laterolog Raw Data

CALIPER

GR

MLR1

MLR2

MLR3

MLR4

STAR

MLL

Multi Laterolog Data Fit

CALIPER

STANDOFF GR

DATA FIT UNINVADED DATA FIT INVADED

MEASURED AND SYNTHETIC

MULTI LATEROLOG

MLL

CALIPER

GR Lxo

Rxo

Rt

MLR1

MLR2

MLR3

MLR4

STAR

Multi Laterolog ABC Corrected Data

Modelled depth of invasion curves

Phiops-7 Model

1

10

100

1 10 100

Depth of Invasion, in

Ap

pare

nt

Resis

tivit

y,

Oh

m-m

MLR4 Mod

MLR3 Mod

MLR2 Mod

MLR1 Mod

STAR Mod

MLR1 Meas

MLR2 Meas

MLR3 Meas

MLR4 Meas

STAR Meas

Borehole 12.25-in.

Mud Resistivity 0.025 Ωm

Flushed Zone Resistivity

2.5 Ωm

Formation Resistivity 70

Ωm

Dot = Measured Value

Best Fit Lxo 0.38 m (15in)

Flushed zone length varies

along the x-axis

Phi-avg = 11%; Sw-avg = 15%

Petrophysical Analysis

Conclusions

• Multi laterolog tool has been run successfully in wells in the Phiops field in Egypt.

• Superior vertical resolution compared to the traditional dual laterolog.

• Additional depth of investigation curves more clearly indicate the effects of

invasion.

• Adaptive borehole correction removed any curve separation in impermeable

zones.

• Rt, Rxo and Lxo in real time.

• Rt estimated as 1.5 times higher than deepest measured curve.

• More accurate water saturation and indication of moveable hydrocarbons.

• Petrophysical analysis confirmed by production data.

• Microresistivity data confirms high resolution of Multilaterolog data

Acknowledgements

The authors like to thank Khalda Petroleum for permission to use the

field data.