Document 415079

Crack at 84m and fracture at 92m Corrosion or other forms of mechanical damages
are commonly seen in cased wells. Corrosion is
caused by equipment-induced or natural
electrical currents that flow in the earth. It may
result in holes or loss of metal in the casing/
tubing, thus weakening the structural integrity of
the wellbore. Casing damages may occur during
testing, drilling of plugs, or well stimulation.
Compromised casing integrity can have a severe
impact on production and the environment.
BGES’ Casing Integrity Evaluation services are
offered to provide extensive corrosion inspection
in production, injection and disposal wells. This
category of service is most useful when
combined with the RCBL for a full evaluation of
casing and cement integrity.
Corrosion Evaluation Tool
The Electro-magnetic Defect Detection tool is
designed to measure wall thickness and detect
various forms of metal loss in the casing, including
cracks and holes. It displays accurately the
downhole pipe string, tool location, and can detect
magnetic material outside casing (such as casing
centralizer, surface casing, etc.).
Specifications
2.5m
Diameter
43 mm
Max. Temperature
175⁰C
Max. Pressure
100 MPa
Min. Hole Diameter
533 mm
Detect metal loss in casing of production, injection
and disposal wells
Max. Hole Diameter
114.3 mm
Range (length)
70 mm — 324 mm
Features & Benefits
Range (wall thickness)
3—12 mm (single layer)
≤ 25 mm (double layer)
Accuracy
± 0.5 mm (single layer)
± 1.5 mm (double layer)
Min. Length of Axial Crack
40 mm (2.5” single layer)
60 mm (5.5” single layer)
130 mm (5.5” double layer)
Min. size of Circum. Crack
1/6 of Diameter
Min. Dia. of hole defect
25 mm
Operation
Multiple conveyance methods are available. The
services can be combined with the RCBL for a
full evaluation of casing and cement integrity.
Measurement
This logging suite is a combination of
electromagnetic log, multi-finger imaging caliper
and gyro inclinometer to effectively evaluate
metal loss and changes in casing geometry.
Borehole
A p p l i c a t i on s
Tool
Length—Active
Cased-hole Logging
C a s i n g In t e g r i t y E v a l u a ti o n
Multi-Finger Imaging Caliper
Gyro Inclinometer
The multi-finger imaging caliper can detect casing
deformation, bending, fracture, holes and inner
wall corrosion using individual measuring fingers.
Displacement of each finger is reflected to its
sensor directly and all the displacement signals
are processed, coded, and transferred to surface
system where a 3D image of the casing can be
generated.
The gyro inclinometer is an effective way to
measure the trajectory, azimuth, inclination and
tool face angle of cased wells. The instrument is
designed based on inertial navigation technology
in the aviation field. Its core sensor consists of a
specialized gyroscope and a silicon flexural
accelerometer protected by an anti-shock design.
The use of a gyroscope makes it not susceptible
to interference from external magnetic field.
The caliper is available in three sizes to fit different
casing diameters: 24 fingers, 40 fingers and 60
fingers
Specifications
Number of Fingers
24 / 40 / 60
Borehole
Max. Temperature
175⁰C
Hole Diameter
≤ 5.5” / 4”—7” / 5.5”—10¾”
Measure
Range
45—150 mm / 80—180 mm /
110—254mm
Accuracy
± 1 mm
New
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Specifications
Max. Temperature
175⁰C (for 4 hours)
Max. Pressure
140 MPa
Angle
Range
0—90⁰
Accuracy
± 0.1⁰
Range
0—360⁰
Accuracy
± 2⁰ (azimuth≥3⁰) Range
0—360⁰
Accuracy
± 2⁰
Azimuth
Tool Face
Orientation
n Big Guns Energy Services
Gyro inclinometer plot 43 mm / 70 mm / 100 mm
Measurement
Diameter
This instrument uses a combination of highprecision sensors, a micro-processing system and
high-performance DSP+FPGA control frame to
substantially improve measurement accuracy.
Borehole
1.42m / 1.36m / 1.44m
Tool
Length—Active
Caliper images 
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