Note: Descriptions are shown in the official language in which they were submitted.
11743S2
METHOD AND APPRATUS FOR
ULT~ASONIC TESTING OF TUBULAR GOODS -_
Background of the Invention
.
1. Field of the Invention
The invention relates generally to method and apparatus
for ultrasonic testing of generally uniform cross-section elongate
goods and, more particularly, but not by way of limitation, it
relates to improved apparatus for defect detection in tubular
goods such as oil well casing, drill pipe, tubing and the like.
2. Description of the Prior Art
The prior art includes numerous methods and varying forms
of apparatus for ultrasonic testing of metallic objects or speci-
mens, and such prior devices have functioned under a variety of
techniques and energy coupling schemes to provide defect and/or
discontinuity indication of the test specimens. It is only
recently that attempts have been made to carry out large-scale
ultrasonic testing of oil field tubular goods and particularly
those methods which carry out the test operation with controlled
relative movement between the testing cell and the specimen goods.
A prior U.S. Patent No. 4,106,347 discloses use of a frame
including a guadrature array of extendable cylinders for moving
wheeled crystal transducer assemblies into contact with a drill
pipe section at a position above the derrick floor during tripping
operations. In this disclosure, four transducers functioning with-
in water filled rubber wheels are maintained in contact with selected
portions of the drill pipe in order to read any defects. Such systems
must contend with extraneous readout of confusing nature due to inter-
,~
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11~43S2
position of diverse materials, such as the energy coupler and the
rubber wheel container structure, prior to transmission of the
ultrasonic energy into the specimen tubular goods. Direct normal
positioning of the energy transducers further imposes limitations
as to types and positions of defects that are detectable.
U.S. Patent No. 3,533,281 discloses another form of ultra-
sonic testing wherein the plural ultrasonic energy transducers
are rotated relative to the tubular goods undergoing test as it
is moved longitudinally relative to the test section. Here again,
ultrasonic energy transducers are aligned directly normal to the
tubular goods and thus enable only a single testing mode of the
specimen material. U.S. Patent No. 3,540,267 discloses yet
another form of drill pipe testing device wherein the drill pipe
is rotated and/or flexed during testing to provide tension and
compression stressing during inspection by relatively conventional
ultrasonic energy transducer assemblies.
Summary of the Invention
The present invention relates to an improved method and
apparatus for ultrasonic testing of tubular goods, particularly
tubular goods as tested while in longitudinal motion relative to
the test apparatus. More particularly, the invention consists of
a circular array of ultrasonic transducers which examine for each
of transverse and longitudinal defects while additional transducers
within the same array verify wall thickness of the tubular specimen.
Slidable seal enclosure means maintains fluid energy couplant in
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11~7~52
envelopment of the circular array while allowing axial movement of
the test specimen relative thereto. The ultrasonic testing array
assembled in coaction with the energy couplant enclosure is then
utilized with associated support apparatus for testing within the
oil well derrick structure during tripping operations; or for
yard testing in place of horizontally stored tubular goods, or for
testing of tubular goods as longitudinally moved therethrough.
Thus, in addition to the testing array and enclosure apparatus
being operatively supported within the derrick structure, the array
and enclosure may be constructed with attached motive means for
carrying the array along the horizontal tubular goods while testing,
or the array and enclosure may be associated with stationary support
structure including motive means for driving the tubular goods
axially through the array while testing.
Therefore, it is an object of the present invention to pro-
vide an ultrasonic test apparatus for tubular goods that effects
plural modes of examination simultaneously.
It is also an object of the invention to provide a tubular
goods testing device which can be operated in any of plural
attitudes to enable testing of oil field tubular goods, either new
or used, in operational or storage position, and without need for
rotation of the tubular goods.
It is yet further an object of the present invention to pro-
vide a device for inspection of oil field tubular goods that may
be bent or twisted.
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It is still further an object of the invention to provide a
pipe testing device that is fire hazard allowable and suitable
for use on board offshore oil rigs.
Finally, it is an object of the present invention to provide
an ultrasonic inspection device situated beneath the derrick floor
for continuous inspection of oil field tubular goods during tripping
operations.
Other objects and advantages of the invention will be evident
from the following detailed description when read in conjunction
with the accompanying drawings which illustrate the invention.
Brief Description of the Drawings
FIG. 1 is a block diagram of the elongate goods test device
of the present invention;
FIG. 2 is a partial section of tubular goods and a transducer
array illus~rating ultrasonic energy paths as utilized in the
present invention;
FIG. 3 is a partial section taken along lines 3-3 of FIG. 2;
FIG. 4 is a top plan view of a transducer array;
FIG. 5 is a vertical section taken along lines 5-5 of FIG. 4;
FIG. 6 is a cross-section of a transducer array block as
taken through the center circumfery of transducer positions;
FIG. 7 is a view in elevation of an ultrasonic testing device
in operational attitude within oil derrick structure;
FIG. 8 is a top view of the testing device of FIG. 7;
FIG. 9 is a side view of the testing device of FIG. 7 with
side plate removed;
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FIG. 10 is a top plan view of the array frame of the present
invention;
FIG. 11 is a partial top view of the array frame with top
plate removed;
FIG. 12 is a section in exploded form astakenon lines12-12 of
FIG. 11;
FIG. 13 is an alternative form of the present in~ention as
it is utilized in combination with a motive assembly;
FIG. 14 is a side elevation of the testing device of FIG. 13;
FIG. 15 is a front view in elevation with parts shown in
cutaway of the testing device of FIG. 13;
FIG. 16 is a second alternative embodiment of the present in-
vention wherein the testing device is used in combination with
stationary structure; and
FIG. 17 isa front view in elvation ofthe testingdevice ofFIG. 16.
Detailed Description of the Invention
Referring to FIG. 1, an ultrasonic testing device 10 functions
to inspect tubular goods 12 utilizing a circular transducer array
14 within an energy coupling fluid enclosure 16. Transducer array
14 consists of an array block 18 as formed from such as aluminum,
plexiglas or the like, and retaining a plurality of ultrasonic
energy receiver-transmitter transducers in selected positioning
around tubular goods 12. A fluid supply 20, e.g. water or suitable
energy couplant, maintains the fluid enclosure 16 to a selected
fill level and sealing members, to be described below, are main-
~17435Z
tained in contact with the tubular goods 12 at the top and bottom
of enclosure 16.
The array block 18 is formed with a central bore 22 having
bevel surface 24 formed at an angle of about 19 from vertical
of the axis of bore 22. A first circumfery of transverse defect
transducers 26 are then disposed in bevel surface 24 in equi-
spaced disposition. Use of twenty-two suchtransverse transducers
26 provides very good circumferal coverage of tubular goods 12.
Within central bore 22, a plurality of equi-spaced longitudinal
defect transducers 28 are disposed. A lesser number of fourteen
to eighteen longitudinal transducers 28 may be utilized. Finally,
around the lower end of central bore 22 are disposed a plurality of
wall thickness transducers 30. The wall thickness transducers 30
may be anywhere from two to eight in number and preferably equi-
spaced in their circumfery about tubular goods 12~ It is alsocontemplated that the wall thickness transducers 30 be interposed
between rows of transducers 26 and 28 to provide additional energy
isolation.
In each case, transducers 26, 28 and 30 may be selected from
the ccmmercially available ceramic types such as barium titanate,
lead methaniobate, lead zirconate titanate, etc. ~he transducers
are highly focused through convex grinding of the face and, in
present deslgn, the transverse and longitudinal defect transducers
26 and 28 are pulsed at 2.25 Megahertz while the wall thickness
transducers 30 are pulsed at 5 Megahertz. A basic oscillator
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system or rate generator 32 provides system timing as it controls
the rate of pulse generator 34 which, in turn, provides energizing
input to the respective transducers 26, 28 and 30. Received
energy from transducers 26, 28 and 30 is then applied to a multi-
channel preamplifier 36 for input to a plural data displayoscilloscope 38 as also controlled from rate generator 32. A chart
recorder 40 may also be utilized to indicate test data depending
upon the operating mode and the exigencies of the application.
Received energy output from transverse transducers 26 may be
appiied in parallel to preamplifier 36; however, present design
utilizes dual inputs as parallel from eleven transducers 26 each
for indication to preamplifier 36. Similarly, the longitudinal
transducers 28 are applied to parallel inputs from each of nine
transducers 28, and wall thickness transducers 30 may ~e applied
in parallel or gated inseparately for wall thickness indication.
The associated electronics is largely conventional and commercially
available although special purpose equipment and digitalized
processing may be utilized. One form of commercially available
equipment for carrying out the method may utilize a Model Mark IV
2a Ultrasonic Flaw Detector as available from Sonic Instruments, Inc.,
in association with a Gould Model 2200 Chart Recorder.
FIGS. 2 and 3 illustrate in greater detail the disposition
and directivity of the transmitter-receiver transducer~ 26, 28 and
30 as disposed in array block 18. A body of energy-coupling fluid
42, water, selected olins, etc., is of course maintained between
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the transducers 26-30 and the outer wall 44 of tubular goods 12.
Each of the transverse defect transducers 26 is aligned within
bevel surface 24 to direct transmitted ultrasonic energy radially
at outer wall 44 and an axial angle of 19 to normal. This energy
then undergoes refraction in accordance with the classical function
(Snell's Law) and is directed to reflection from the inner wall of
46 of tubular goods 12 with a portion of the energy continuing on
for reflection from outer wall 44. Reflected energy along this
traverse then returns along essentially the same paths for detection
by transducer 26. Any defect or discontinuity within the wall of
tubular goods 12 will appear as an abnormal energy indication when
viewed on the operating equipment. The wall thickness transducers
30 are pulsed at a higher frequency, e.g., 5 Megahertz, and are
direct viewing normal to the outer wall 44 of tubular goods 12 to
provide a straight-through path with detection of return energy.
The return or received energy is then processed through a tolerance
gate indication to indicate any variation in wall thickness as
between inner wall 46 and outer wall 44.
Referring also to FIG. 3, the longitudinal transducers 28
are aligned normal to the axial dimension of tubular goods 12 but
angled in the transverse plane to obtain a scan view of a section
of the tubular goods wall. The longitudinal defect transducers
28 are mounted at an angle of 15.5 shifted transversely from the
radial to provide shear waves within the pipe wall, this angle and
spacing providing scan of sufficient arc sector of tubular goods
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12 while also avoiding any inter~erence as between transducers 28,
i.e., each transducer 28 aan only receive its own reflected energy.
Here again, ultrasonic energy directed from transducers 28 undergoes
refraction at outer wall 44 with reflection from inner wall 46 and
outer wall 44 for return back to transducer 28. Proper calibration
of the operating sensitivity clearly differentiates the dual
reflection path as indicated in the operating equipment.
FIG. 4 illustrates a complete array block 18 as it may be
divided into two halves 48 and 50. A plurality of equi-spaced bores
52 are formed at proper angle in bevel surface 24, see also FIG. 5,
the bores 52 receiving the transverse transducers 26. In like
manner, and referring to FIG. 5, a plurality of equi-spaced bores
54, e.g., a quadrature array, are formed for reception of the wall
thickness transducers 30. Referring also to FIG. 6, the mid-~roup
or bores 56, in this case twenty, are similarly formed at their
proper angular relationship in the plane transverse to central
bore 22 of array block 18.
The array block 18 may be formed from such as aluminum, plexi-
glas, etc., and after formation of all bores 52, 54 and 56, the
respective transmitter-receiver transducers may be bonded in posi-
tion with the remainder of the bores sealingly filled with a
suitable potting compound. Electrical leads, i.e., pulsing and
receiver leads from each of the transducerF, may then be inter-
connected in whatever the selected paralleling interconnection and
2~ potted within a groove (not shown) as formed about the periphery of
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block array 18 thereby to provide a single, watertight connector
conduit for each respective bank or tier of transducers.
FIG. 7 illustrates a testing device 60 in installation within
an oil well derrick. Thus, the installation includes the conven-
tional equipment such as blowout preventers 62 covering borehole
casing 64 with drill pipe 66 extending down through derrick rig
floor 68. A casing and bell nipple 70 extend above blowout pre-
v~nters 62 and the return mud line 72 is drawn therefrom. The
ultrasonic testing device 60 is then semi-rigidly supported on
bell nipple 70 by means of a plurality of spring lines 74 which
attach to the derrick superstructure under carriage. Eye bolts
76 are provided on the frame of testing device 60 for securing
while fluid level control is enabled via inlet conduit 78 and
outlet conduit 80, and electrical connections are made via conduit
1~ 82. Thus, testing device 60 is secure above bell nipple 70 yet
has sufficient freedom of movement to shift laterally with any
shifting of drill pipe 66 wihin borehole casing 64.
FIGS. 8and 9 illustrate testing device 60 as it consists of
a fluid enclosure formed by side plates 84, front and back plates
86 and top and bottom plates 88. Top and bottom plates 88 each
include a central bore 90 through which the workpiece passes
vertically, and an array frame 92 is suspended in alignment with
upper and lower bores 90. An upper panel 94 having a central bore
96 is secured between side plates 84, and a rigid rubber sealing
member 98 having a narrowed bore 100 is retained between upper
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panel 94 and upper plate 88. In like manner, a lower panel 102
having central bore 104 is secured between side plates 84 to re-
tain a lower rubber panel or sealing member 106 having bore 108
in secure juxtaposition against bottom plate 88.
The array frame 92 is constructed as spearable halves and is
retained in the operative position by means of retaining springs
110, and array frame 92 may be suspended in operative position
within the ~luid enclosure of device 60 by means of a suitable
quadrature array of upper retaining springs 112 and lower retain-
ing springs 114. Conventional fastening and securing techniques
may be utilized in construction of the testing device 60.
FIGS. 10, 11 and 12 illustrate a basic array frame 92 in
greater detail. Referring to FIG. 10, the array frame is separable
into two halves 116 and 118 as separated along inner edges 120.
Halves 116 and 118 include a top plate 122, 124 which cooperate to
define a bore 126 through which the test piece or drill pipe 66
passes. The top plates 122 and 124 then may include a quadrature
array of guiderollers 128, 130, 132 and 134 which are each adjustably
mounted by fasteners 136 to enable radially inward positioning to
accommodate various sizes of workpiece, i.e., drill pipe, casing,
tubing and the like. It should be noted that guide rollers 128, 130,
132 and 134 are not required in vertical testing applications such as
that of FIGS. 7, 8, and 9, but only in longitudinal applications as
will be further described below.
As shown in FIG. 11, with top plates removed, the array frame
92 includes opposite side panels 140 and 142 as adjoined to mating
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1~7~3~
bottom plates 144 and 146, respectively. The frame half 116
includes opposite end panels 146 while opposite frame half 118
includes opposed end panels 148. The array frame half 118 also
includes a guide roller assembly (see FIG. 12) consisting of a
plate 150 and a plurality of guide rollers 152 suitably mounted
as with fasteners to the inner side of opposite end plates 148.
Thus, the guide roller assemblies function to guide and properly
align the opposite frame halves 116 and 118 a~ they are initially
assembled around a workpiece into operative position.
FIGS. 13, 14 and 15 illustrate an alternative fo~m of the
invention wherein the basic fluid enclosure and ultrasonic testing
array are utilized with motive means enabliny progression along
a tubular goods specimen when in the horizontal attitude. This
buggy-type testing apparatus may be utilized with elther new or
used tubular goods as it may be placed in storage areas. Thus,
referring to FIG. 13, a fluid enclosure box 160, including the
basic type of transducer array, is coupled with a drive assembly
162 such that the unit may be manually placed on horizontally
stored tubular goods and energized to traverse therealong while
continuously testing the goods with ultrasonic energy scanning.
The drive assembly 162 consists of a main chassis of inverted V-
shape consisting of front plates 154, 166, side plates 168, 170,
and rear plates 172, 174. Gripping handles 176 and 178 are weld-
secured to the respective side plates 168 and 170 to enable manual
handling and positioning of the tester.
117~3~2
Electric drive motors 180 and 182 are suitably mounted with
respective gear boxes 184 and 186 on respective lower ends of the
chassis channel members. As shown in FIG. 15, motor 180 and gear
box 184 provided rotational input on a drive shaft 188 as journaled
in a bearing mount 190 (FIG. 15) and carrying a drive wheel 192 in
gripping contact with tubular goods 12. Similarly, drive motor
182 and gear box 186 provide rotational input to a drive shaft 194
as journaled in bearing mount 196 and carry.ing a drive wheel 198
in gripping contact with tubular goods 12 on the opposite side.
The bearing mounts 190 and 196 may be such as weld-secured to
respectivP rear plates 172 and 174; and, the drive wheels 194 and
198 may be formed of suitable soft rubber, splined steel rollers
or the like, having good gripping characteristics for moving the
tester along the tubular goods 12.
Referring also to FIG. 14, the forward end of the tester is
maintained in balanced alignment by means of adjustable guide
wheels 200 and 202 as carried on support arms 204 and 206. Each
of support arms 204 and 206 is adjustably carried on respective
adjusting screws 208 and 210 as mounted in spaced screw blocks
212 secured on front plates 164 and 166.
The fluid enclosure box 160 is constructed of generally
cubical form but it is formed to be bisectable along the horizontal
midline 214 to form upper and lower container sections 216 and 218.
Upper container sectlon 216 is positioned with the front panel 220
secured as by welding to the rear plate 172 of drive assembly 162.
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The lower section 218 is removable and sealably positionable in
fluid-tight coaction with upper section 216 by means of latch
hinges 222 and 224.
Upper section 216 includes a semi-circular section of trans-
ducer array frame 226 as affixed by a bracket 228 within upper
section 216. In similar manner, the lower enclosure section 218
,includes a mating semi-circular transducer array frame 230 as
affixed on a mounting bracket 232 within lower section 218. The
transducer arrays within frame sections 226 and 230 may be con-
structed in like manner to those previously disclosed with each of
transverse defect, longitudinal defect and wall thickness trans-
ducers aligned for inspection of the tubular goods 12.
Rubber seal sections 234 and 236 are removably secured
adjacent the respective forward wall 220 and rear wall of upper
section 216 for positioning in sealing engagement around tubular
goods 12. Also, lower section 218 includes forward and rear
rubber seals 238 and 240.
Upper and lower disposed adjustable guide rollers 242 (rollers
128-134, FIG. 10) are disposed on each side of array frame 226 and
230, and these rollers may be adjustably positioned in accordance
with the diameter of tubular goods 12 undergoing test. In like
manner, the rubber seals 234, 236, 238 and 240 would be replaced
with seals defining the proper diameter of aperture, and the forward
guide arm 206 would be adjustably positioned by rotation of the
screw 210 for proper coaction and alignment with tubular goods 12
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to maintain the tester in a balanced attitude during operation.
In operation, the tester may be manually placed on a section
of tubular goods 12 to be tested whereupon the lower enclosure
section 218 is placed in sealing engagement and latched into
S position around tubular goods 12. Thereafter, energy couplant
fluid is introduced to fill the internal void of enclosure 160
and the electric drive motors 180 and 182 are energized to move
the tester along the tubular goods section 12. As the tester moves,
the transducer array is under continuous pulsed energization ~ith
readout being applied to an operator station. The fluid enclosure
160 holds more than enough water such that leakage is minimal
during traverse of the tester along a normal length of tubular
goods 12 and fluid refill of enclosure 160 may be carried out each
time the tester is repositioned for a traverse along a tubular
goods section; however, continual supply and drainage can be
applied to maintain the fluid enclosure 160 full during some
special operations of the testing unit.
Referring to FIGS. 16 and 17, a stationary testing unit 250
is suitably supported on a base 252 to receive tubular goods 12
for driven movement therethrough as ultrasonic testing is effected.
The device 250 includes a frame 254 having a plurality of vertical
upright members 256 in support of transverse frame members 258 and
top fr~me members 260. A testing enclosure box 262 i5 removably
supported between transverse frame members 258 and 260. Enclosure
box 262 may be similar in all respects to those perviously discussed
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352
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which include a transducer array frame 264 having the requisite
transducer array with transverse defect, longitudinal defect and
wall thickness transducers. The front and back entries to
enclosure box 262 are then suitably sealed by rigid rubber sealing
means 266 and 268 which maintain a quiescent fluid environment
within box 262. Array frame264 may include the adjustable guide
rollers 128-134 as shown in FIG. 10.
Support brackets 270, as secured to transverse member 258,
support drive wheels 272 on a drive shaft 274 as rotated by a drive
motor 276. On the opposite side of frame 254, support brackets
278 support a pair of idler wheels 280 in proper spacing to support
the tubular goods 12 in balanced attitude during its passage
through testing device 250. A pair of forward tension rollers 282
are supported on an adjustable support bracket 284, and rear tension
rollers 286 are similarly supported in an adjustable support bracket
288 as secured from transverse top frame 260. The forward and rear-
ward tensions rollers 282 and 286 may be adjustably set in ele-
vation to accommodate various sizes of tubular goods 12.
Fluid for energy coupling is continually supplied to the
transducer enclosure box 262 by means of inlet tube 290 from a
storage tank 292. Leakage of fluid from the enclosure box 262 is
then caught within a splash pan 294 supported within transverse
frame 258, and the leakage fluid is then flowed thorugh conduits
296 into reservoir 298. Fluid from the reservoir 298 is continually
circulated by a motor driven pump 300 via conduit 302 for return to
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the upper storage tank 292. Preferably, storage tank 292 includes
FILL and REFILL float switches in control of pump 300 to maintain
proper level of fluid therein.
The stationary testing device 250 is suitable for use in
ultrasonic testing of elongate tubular gGods either new or used.
The tubular goods 12 may be entered within enclosure box 262
whereupon fluid fill is effected; thereafter, the transducer
testing array is energized in accordance with operator requirements
and drive motor 276 moves the tubular goods 12 through the enclo-
sure box 262 at a uniform rate as testing proceeds. Adjustment ofthe tension rollers 282 and 286 enable acceptance of a combination
of diverse sizes of tubular goods, and the size and positioning of
transducer enclosure box 262 may also be varied in accordance with
the exigencies of the particular operations.
The foregoing discloses a novel approach to continuous ultra-
sonic testing of tubular goods and the several forms of specific
apparatus enable testing of tubular goods in operational attitude,
in storage attitude, in assembly line handling, etc. The specific
form of transducer array provides a greater degree of scanning
coverage of the specimen while simultaneously examining for each of
transverse defects or discontinuities, longitudinal discontinuities
and wall thickness of the goods. Testing consistency is of high
reliability since the system remains constant after initial set-up
and calibration of the ultrasonic control circuitry.
Changes may be made in combination and arrangement of elements
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as heretofore set forth in the specification and shown in the
drawings; it being understood that changes may be made in the
embodiments disclosed without departing from the spirit and
and scope of the invention as defined in the following claims.
1 ~,
