LWD High Resolution Ultrasonic Imager Deliver Innovative ...€¦ · Weatherford ©2018 Weatherford International plc. All rights reserved. LWD Acoustic Imager –Caliper Measurement

Weatherford

©2018 Weatherford International plc. All rights reserved.

Davide Di Tommaso

Operation Manager LWD Petrophysics, North Sea and Continental Europe

LPS New Technology Seminar, London, January 10th 2019

LWD High Resolution Ultrasonic Imager Deliver Innovative Solutions

Weatherford


LWD Electrical Vs Ultrasonic Micro-Imaging

UltraWaveTM (Ultrasonic) SineWaveTM (Electrical)

Sensor Resolution 0.375” Transducer size. Reflection –

type measurement limited to features of

impedance changes.

0.2” and 0.5” Electrode size, can detect

much smaller features due to the ability

of injected current to penetrate fractures.

Mud Type WBM and OBM WBM

Sensitivity to Mud Salinity No Yes

Sensitivity to Mud Weight/Velocity Yes Limited to WBM

Borehole Caliper Measurement Yes No

Sensitivity to Standoff Very Tolerant High

Temperature and Vibration Effects on

Sensor Performance

None None

Weatherford


LWD Acoustic Imager – Caliper Measurement

The standoff between the tool and the borehole

wall is calculated as the mud velocity times the

arrival time divided by two.

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Borehole Quality and Key Seat

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LWD Acoustic Imager – Amplitude Image

Weatherford


High Resolution Acoustic Imager - Outputs

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Bedding

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Disconformity

An unconformity between

parallel layers of sedimentary

rocks which represents a

period of erosion or non-

deposition. Fractures and

coarse particles seen on

amplitude images indicate the

presence of alteration zone.

The anomaly is revealed also,

by resistivity and nuclear

curves.

Weatherford


Facies Differentiation

Carbonaceous lenticular

bedding in SandstoneThin limestone and shale layers

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Fault

Discordant feature

showing evidence of

fault movement by

offset bedding.

Weatherford


Enhanced fractures

The fracture appeared

on the images as

partially or fully open;

occasionally with some

trace of cementation

along it plane.

Weatherford


Breakouts

Breakout were identified both

on ultrasonic amplitude image

and oriented Schmidt plot

derived from “travel-time”

measurement (two different

sources which confirm one

each other)

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Closed and Open Fractures

Weatherford


Carbonate Reservoir Amplitude Image - Vugs1:10 Log Scale

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Macro-porosity

A) Combination of meso

(matrix) and macro

porosity

B) vuggy porosity

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Complex Reservoir

15

Weatherford


Macro-porosity from Ultrasonic Amplitude Images

16

Amplitude image is

responding almost 100% to

matrix porosity

Bimodal histogram with high

amplitude still responding to

matrix porosity and low

amplitude to macro porosity

Weatherford


Example: Carbonate

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Total porosity

from Neutron

Cut off based on the experience, local knowledge and/or calibration data, generates a binary image where

black points are the bins with low amplitude. Based on the relationship between low and high amplitude

bins times any porosity measurement you can calculate the contribution of the vuggy porosity.

LWD High Resolution Ultrasonic Imager Deliver Innovative ...€¦ · Weatherford ©2018 Weatherford International plc. All rights reserved. LWD Acoustic Imager –Caliper Measurement

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