Apparatus for operating wireline tools in wellbores

A downhole tool is supported by coilable tubing extending into the wellbore from a tubing injection and withdrawal apparatus and includes an elongated electrical signal transmitting cable extending through the tube between the tool and the injection apparatus. The tool is connected to one end of the tube by a connector assembly which provides for limited swiveling movement of the tool relative to the end of the tube to preclude excessive lateral loads from being exerted on the tool during positioning of the tool in the wellbore. The connector assembly includes a frangible coupling comprising coupling members which are interconnected by shearable pins whereby separation from the tool will occur at the connector assembly in the event the tool becomes stuck in the wellbore. One of the coupling members includes a fishing neck for engagement with a suitable fishing tool whereby the downhole tool may be retrieved if separated from the tubing. Fluids may be pumped downhole through the tube and the connector assembly to provide improved downhole operating methods.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention pertains to a system for positioning certain downhole 
tools in wellbores using coiled metal tubing having an electrical cable or 
wireline disposed therein and including connector apparatus at each end of 
the tubing for supporting the downhole tool and providing a take off point 
for the electrical cable, respectively. 
2. Background 
In various downhole operations in wellbores for producing hydrocarbon 
fluids certain difficulties arise in positioning downhole tools, 
particularly in deviated wells. For example, various types of electrically 
operated downhole tools, such as logging sondes and perforating tools, are 
usually lowered into the wellbore at the end of a flexible armored cable 
or wireline. In deviated wells, in particular, the positioning of downhole 
tools at the end of a flexible cable such as a wireline, can become 
particularly difficult since gravity alone may not be sufficient to lower 
the tool into the desired position in the wellbore. Moreover, if the tool 
tends to become stuck or resists pull-out operations, the wireline cable 
will stretch much like a rubber band before the holding force is overcome 
such that the performance of logging operations, for example, may be 
highly inaccurate. 
In this regard, it has been suggested to position downhole tools with a 
somewhat more rigid positioning member such as coilable metal tubing which 
is used in various other types of well operations. U.S. Pat. No. 3,401,749 
to W. L. Daniel, for example, suggests positioning a logging tool in a 
deviated wellbore using coilable metal tubing within which the wireline 
cable is extended. However, certain problems associated with positioning 
downhole tools with coilable tubing have heretofore been unsolved. Among 
those problems is locating or centering a logging tool, for example, in 
the wellbore, which may be impossible if the tool is rigidly connected to 
the relatively inflexible tubing. Moreover, with prior art arrangements, 
moving logging and other types of downhole tools into and out of deviated 
wellbores using coilable tubing also results in urging the tool against 
the side of the wellbore with such force as to risk damage to the tool or 
the wellbore and to prevent desired positioning of the tool. 
Other problems associated with positioning down-hole tools in wellbores 
using coilable tubing include providing suitable means for separation of 
the wireline cable at a location which will permit retrieval or fishing 
operations to be carried out and to prevent the possible accumulation of 
several hundred feet of wireline piled on top of the logging tool in the 
event of cable failure at a point substantially uphole from the tool 
itself. There are several other problems and desiderata which have been 
solved and have been provided by the apparatus and method of the present 
invention as will be further appreciated by those skilled in the art. 
SUMMARY OF THE INVENTION 
The present invention provides an improved system for positioning downhole 
tools in subterranean wellbores using elongated, coilable metal tubing as 
the primary positioning structure and wherein an electrical cable or 
wireline is extended inside the tubing between the tool and suitable 
recording or control apparatus on the surface. 
In accordance with one aspect of the invention, there is provided an 
improved connector between a downhole tool and the lower or distal end of 
a relatively stiff coilable metal tube which provides for limited freedom 
of movement of the tool relative to the tube to facilitate movement of the 
tool within the wellbore and to minimize damage to the tool during 
insertion and movement of the tool within the wellbore. 
In particular, a connector assembly is provided which includes a coupling 
device providing for limited movement of the tool relative to the end of 
the tubing section to which the tool is connected. The connector assembly 
also includes an improved arrangement for securing a wireline cable to 
prevent stressing of the cable conductors or pullout of the cable from its 
connection to the downhole tool. The connector assembly still further 
provides a frangible coupling which will provide for separation of the 
tool from the tube at a predetermined tension or pull-out force exerted on 
the tube and at a location which will substantially preclude separation of 
the wire-line cable at a point which would result in accumulation of cable 
in the wellbore above the tool or above the point whereby suitable tool 
retrieval operations could not be carried out. 
The present invention still further includes an improved connector sub and 
an improved centralizer arrangement whereby fluid may be injected into the 
wellbore through the coilable tube at a point in the wellbore close to the 
tool. The connector assembly is adapted to be used in conjunction with 
improved methods of operating downhole tools wherein fluids may be 
injected into the wellbore in the immediate vicinity of the tool to 
displace or condition certain well fluids and to facilitate the operation 
of certain wellbore imaging tools. Such operations, as drawdown, using 
nitrogen gas and providing cooling fluids to prevent degradation and 
damage to tools in high temperature wellbores are also made possible or 
more convenient to perform with the present invention. 
The present invention further provides an improved system for positioning a 
downhole tool in a wellbore using coilable tubing in which an electrical 
cable is run and wherein the cable exits the tubing at a takeoff point 
within a tubing storage reel and through an improved connector assembly at 
the upper end of the tubing. 
The present invention provides several advantages in positioning and 
operating downhole well tools, including logging tools and perforation 
apparatus. The system eliminates problems associated with positioning 
downhole tools with stranded flexible cable or wireline in both open and 
cased hole operations and provides for a more accurate positioning of 
devices, such as logging tools, with minimal changes of damaging the tools 
themselves. The system also presents sufficient rigidity of the tool 
support structure to prevent tools such as perforating guns from being 
blown up the wellbore during perforating operations. Other advantages of 
the system include providing for introduction of fluids into the wellbore 
prior to or during logging and perforating operations to provide more 
accurate and higher resolution logs or other inspection processes and to 
minimize the change of the downhole tool becoming stuck in the wellbore.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
In the description which follows, like parts are marked throughout the 
specification and drawing with the same reference numerals, respectively. 
The drawing figures are not necessarily to scale and certain features of 
the invention may be shown exaggerated in scale or in somewhat schematic 
form in the interest of clarity and conciseness. 
Referring to FIG. 1, there is illustrated in somewhat schematic form a 
system for locating a logging tool or other type of downhole tool in a 
wellbore using what is known in the art as coiled tubing. In FIG. 1 there 
is illustrated a deviated well, generally designated by the numeral 10. By 
way of example, the well 10 includes a generally vertically oriented 
section 12 provided with suitable well casing 14 and a deviated section 
16, a portion of which may be uncased and indicated as a wellbore 18. 
Deviated wellbores may assume various orientations and in the search for 
and development of hydrocarbonbearing formations in more inaccessible 
locations, wellbores which transcend from substantially vertical to 
substantially horizontal orientation have been considered and drilled. The 
well illustrated in FIG. 1 includes a conventional wellhead 20, a blowout 
preventer 22, and a conventional lubricator assembly 24, including means 
for inserting and removing tools for traversal of the wellbore. The 
lubricator 24 includes a suitable stuffing box 26 through which an 
elongated coilable metal tube 28 has been inserted and extended into the 
wellbore as illustrated. 
The tube 28 is of a type well known for use in carrying out various well 
opeations and typically comprises a relatively thin-walled steel tube 
which may be plastically deformed and stored on a suitable reel, generally 
designated by the numeral 30. The reel 30 is part of a coiled tubing 
injector unit 32, also having a rotatable spool 34 over which the tube 28 
is trained and straightened by a series of propelling and straightening 
rollers 36. The tubing injector unit may take various forms and the unit 
32 is illustrated basically by way of example only. The reel 30 may be 
rotated by suitable motor means, not shown, and mounted for rotation on a 
suitable support structure 38, including a bearing 40, see FIG. 2 also. 
The reel 30 may be adapted to store several thousand feet of tube 28 in a 
manner not unlike the storage of flexible cable. The upper end of the tube 
28 is indicated by the numeral 40 in FIGS. 1 and 3, and is connected to a 
suitable conduit 42 which, as illustrated in FIG. 2, is in communication 
with a passage 44 formed in the interior of a central support shaft 46 for 
the reel 30. The shaft 46 is connected to suitable radially extending 
spokes 48 and is itself supported in spaced apart bearings 40, one shown 
in FIG. 2. Fluid may be introduced into the passage 44, the conduit 42 and 
the interior of the tube 28 by way of a suitable swivel connector assembly 
which may, as shown by way of example, be formed by a distal end of the 
shaft 46 and a cap member 50 which is secured in a suitable manner to be 
stationary relative to the bearing 40. The cap 50 is connected to a 
suitable conduit 52 which is adapted to be in communication with a source 
of pressure fluid in either liquid or gaseous form, not shown in the 
drawing figures. 
Referring further to FIG. 2, the shaft 46 is also adapted to include a 
slip-ring arrangement for a plurality of electrical conductors 54 which 
are suitably electrically connected to an electrical cable disposed within 
the tubing 28 and to be described in further detail herein. An 
intermediate cable is generally designated by the numeral 60 in FIG. 2 and 
is suitably connected to the shaft 46 by a connector 62. The conductors 54 
are in communication with respective electrical conductor rings 64 by 
which electrical signals may be transferred to conductor means 66 
supported on a stationary slip-ring housing 68. A further detailed 
description of the slip-ring assembly comprising the slip-rings 64 and the 
housing 68 is not believed to be necessary to enable one skilled in the 
art to practice the present invention. Various types of electrical 
slip-ring assemblies are commercially available which would be suited or 
adapted for use in connection with the system of the present invention. 
Referring now to FIGS. 3 and 4, the cable 60 is connected to an upper end 
connector assembly 69 for an electrical cable or wireline 70 which extends 
through the tube 28 from the tubing injector unit 32 to the lower end of 
the wellbore 18 for transmission of suitable electrical signals to a tool 
such as an elongated well logging tool 71, FIG. 1, shown disposed in the 
wellbore 18. Those skilled in the art will recognize that various types of 
tools may be substituted for the logging tool 71 and which are adapted to 
receive and transmit signals between the wellbore 18 and a suitable 
surface apparatus, such as a control apparatus 72 shown in FIG. 1, and 
suitably connected to the conductors 66. 
Referring further to FIGS. 3 and 4, the upper end portion 40 of the tube 28 
includes a branch portion 74 which is coupled to the upper end connector 
69 for the wireline cable 70. The cable 70 may take various forms but 
typically is a conventional wireline cable which may include a plurality 
of insulated electrical conductor wires 78, FIG. 4, which are contained 
within an outer shell or armor made up of plural layers of wound steel 
wire or other suitable filamentary materials. In the example shown, the 
cable 70 includes an inner layer of wound steel filaments or wires 79 and 
an outer layer of steel filaments or wires 80 which are wound in opposite 
directions around the core of the cable formed by the plural conductor 
wires 78. The layers of steel filaments 79 and 80 serve as a relatively 
flexible protective armor and tensile load bearing structure for the cable 
70 and may or may not be covered with an outer layer of insulation or a 
suitable protective coating. The cable 70 extends entirely through the 
tube 28, including the branch portion 74, between the upper end connector 
assembly 69 and a lower connector assembly 84, FIG. 1. 
Referring again to FIG. 4, the upper connector assembly 69 includes a 
generally cylindrical body member 86 having an elongated stepped bore 88 
extending therethrough and being formed with suitable internal pipe 
threads 90 at one end and suitable internal machine threads 92 at the 
opposite end. The connector body 86 is connected to the tube branch 
portion 74 by a conventional tube fitting assembly 94 having a body member 
96 threadedly engaged with the connector body 86 and a nut 98 threadedly 
connected thereto. An enlarged portion 100 of the bore 88 is adapted to 
receive a generally cylindrical cable anchor body 102 having a 
frustoconical bore 104 formed therein and which is adapted to receive a 
frustoconical plug 106 adapted to fit within the bore 104, as illustrated. 
The plug 106 and the bore 104 are dimensioned such as to receive a 
plurality of the armor filaments 79 and 80 which are preferably unwound 
and inserted in the bore 104 to be clamped between the plug 106 and the 
body 102. The plug 106 is retained in the bore 104 by a clamp washer 108 
which also clamps the distal ends of the filaments 79 and 80 against a 
transverse end face 110 of the body 102. The plug 106 and the washer 108 
are secured in their cable clamping position by a hollow spacer 112 and a 
nut 114 which is threadedly engaged with the end of the connector body 86, 
as illustrated. The nut 114 includes suitable spaced apart o-ring seals 
116 disposed on the periphery thereof and adapted to be in sealing 
engagement with the bore 100 to prevent fluid leakage from the end of the 
connector body 86. The nut 114 is also provided with a head 117 which is 
preferably of generally hexagonal configuration in cross section, not 
shown, to provide for application of conventional wrench to the nut for 
securing it to the connector body 86. The nut 114 also includes an axially 
extending head portion 118 which is preferably externally threaded and 
adapted to receive a connector member 120 for the cable 60. The connector 
120 is adapted to house part of a commercially available plug and socket 
connector ssembly, including a plug portion 122 which can be fitted in a 
bore 119 formed in the head portion 118 and a socket member 124 which is 
preferably disposed in a stepped bore 126 formed in the nut 116. The 
socket member 124 is adapted to include a plurality of individual 
terminals, not shown, which are each connectable to one of the conductor 
wires 78, respectively, whereby signals transmitted by the wires 78 may be 
transferred to the cable 60. The spacer 112 defines a chamber 115 wherein 
a strain relief coil 81 may be formed in the conductor wires 78. The plug 
106 and the washer 108 are suitably bored to provide a passage for the 
conductor wires 78. 
The aforedescribed arrangement of the connector assembly 69 offers several 
advantages for terminating a wireline cable such as the cable 70 at the 
upper end of a section of elongated coilable tubing such as the tube 28. 
The cable anchor body 102, plug 106 and washer 108 provide means for 
securing the cable jacket or armor sheath comprising the filaments 79 and 
80 at the upper end of the cable 70 to eliminate any longitudinal strain 
on the conductor wires 78. Moreover, the connector 120 and plug 122 
provide for disconnecting the cable 60 from the connector assembly 69 and 
removal of the nut 114 to provide for access to the spacer 112 and the 
cable retaining plug and body parts. The connector 69 is essentially a 
fluid-tight structure when assembled and may be injected with a suitable 
grease or the like into the bore 88 through a conventional fitting 130 to 
form a barrier between fluids which are being pumped through the tube 28 
and the connector assembly itself. 
Referring now to FIGS. 5 through 7, the lower connector assembly 84 
includes an elongated, generally cylindrical sub member 136, FIG. 5A, 
having an enlarged diameter head portion 138 and an elongated bore 140 
which extends from a fishing neck 142 to a first enlarged bore portion 
143. A shank portion 137 of the sub is provided with several rows of 
threaded fastener receiving holes for receiving tube retaining fasteners 
139 so that the distal end of the tube 28 may be suitably secured to the 
sub 136. A set of fluid injection holes 146 are provided in a 
circumferentially spaced pattern and open into the bore 140 to provide 
communication of pressure fluid between the tube 28 and the wellbore 18. 
One or more of the holes 146 may be plugged by insertion of a suitable 
threaded member such as a headless socket head screw or the like, not 
shown. 
Referring to FIGS. 5A and 7, the shank portion 137 of the sub 136 is 
adapted to be relatively loosely journaled by a centralizer member 148 
having opposed longitudinally separable centralizer sections 150 and 152 
which are secured together at a parting line 153 by spaced apart fasteners 
154, suitably threaded into tapped holes in the section 150. The 
centralizer 148 is provided with conventional fluid conducting passages 
155 and is of a diameter suitable to aid in locating the tube 28 generally 
coaxial in the bore of the casing 12. Although the sub 136 is adapted for 
use with the centralizer 148, those skilled in the art will recognize that 
the use of the centralizer is not mandatory and the improved lower 
connector assembly 84 is particularly adapted for connecting the tool 71 
to the tube 28 with or without the use of the centralizer. 
Referring further to FIG. 5A, the end of the cable 70 opposite the end 
attached to the connector 82 is anchored in the sub 136 by unraveling ends 
of the the armor filaments 79 and 80 and removing some of the unraveled 
filament ends surrounding the conductor wires 78. The unraveled armor 
filaments 79 and 80, not removed or cut off, are secured between a second 
cable anchor body 102, plug 106 and washer 108 disposed within the bore 
142, as illustrated, and secured therein by a lock nut 152 which is 
threadedly engaged with cooperating internal threads 154 forming a further 
enlarged portion of the bore 140. The lock nut 152 includes a longitudinal 
bore 156 formed therein and providing a passage for the insulated 
conductor wires 78. 
The enlarged head portion 138 of the sub 136 includes a further enlarged 
bore portion 160 which is counterbored and internally threaded at 162. The 
bore portion 160 is intersected by opposed radially extending elongated 
slots 164, see FIG. 6 also, which are adapted to receive opposed trunnions 
166 extending into the slots 164 and projecting from the head 168 of a 
coupling member 170. The coupling member 170 includes a shank 172 which is 
threaded on its distal end and is adapted to be threadedly engaged with an 
elongated cylindrical coupling body 174. The coupling body 174 is also 
illustrated in FIG. 5B which is an extension of FIG. 5A from the parting 
line a-a in both drawing figures. The coupling body 174 includes an 
elongated bore 176 formed therein which extends to a transverse wall 177 
in which a frustoconical recess 178 is formed and opens into a central 
passage 180 for receiving the conductor wires 78. 
Referring back to FIG. 5A, the coupling member 170 extends through 
relatively large bore 182 formed in a head 184. The head 184 includes an 
externally threaded portion 185 for engagement with the threads 162 to 
secure the head to the sub 136, as illustrated. A generally spherical 
bearing surface 186 is formed on the head 184 and is engageable with the 
hub 168 of the coupling member 170 for retaining the coupling member 
connected to the sub 136. The diameter of the bore 160, the axial width of 
the slots 164 and the span of the trunnions 166 of the coupling member 170 
is such that the coupling member may be inserted into the bore 160 and the 
trunnions 166 extended into the slots 164 and retained therein by 
threading the head 184 into engagement with the sub head portion 138. 
However, when assembled as illustrated in FIG. 5A, the coupling member 170 
cannot be displaced sufficiently laterally to allow the trunnions 166 to 
move out of the slots 164. An axial passage 175 extends through the 
coupling member 170 to provide a wireway for the conductor wires 78. 
The coupling member 170 may rotate only a limited degree about its 
longitudinal axis 173 so that rotational orientation of the tube 28 will 
assure a related rotational position of the tool 71 within the angular 
excursion limits of the coupling member 170 provided by the slots 164 and 
the trunnions 166. The head member 184 includes a flange 187 having a 
hexagonal cross sectional shape to permit engagement by a suitable wrench 
for tightening the head in engagement with the sub 136. The coupling 
member 170 is also locked in engagement with the coupling body 174 by a 
generally cylindrical locknut 190 having one or more radially disposed set 
screws 192 threadably engaged therewith and adapted to secure the locknut 
190 nonrotatably relative to the shank of the coupling member 170. The 
coupling body 174 may be formed to have a fishing neck on the end of the 
coupling body into which the member 170 is threaded in the unlikely event 
that the member 170 should fail. 
The lower connector assembly 84 further includes a frangible coupling 
section including the body 174 and an elongated, generally cylindrical 
coupling member 194, FIG. 5B. The coupling member 194 includes a reduced 
diameter portion 196 having a fishing neck 198 formed thereon and 
including a generally frustoconical nose surface 200 and an opposed, 
generally transverse shoulder 202. The coupling member 194 includes means 
forming an elongated longitudinal passage 204 extending therethrough for 
receiving the conductor wires 78. The end of the coupling member 194 
opposite the fishing neck 198 is provided with internal threads 206 for 
receiving a nipple 208 in threaded engagement therewith. A suitable washer 
210 is disposed in the bore formed by the threads 206 and forms a closure 
for a bore 209 in the nipple 208 and for retaining a connector retaining 
sleeve 212 within the bore 209. The nipple 208 includes a transverse 
retaining collar 214 for a nut 216. The nut 216 is adapted to engage a 
cooperating projection 218 formed on the tool 71 for connecting the tool 
to the connector assembly 84. The conductor wires 78 extend into a 
suitable plug member 220 which is retained in the bore 209 by the sleeve 
212. The plug member 220 includes suitabe terminals, not shown, for 
electrical connection of the conductor wires 78 to further conductor means 
within the tool 72. A detailed description of the plug member 220 is not 
believed to be necessary to an understanding and practice of the present 
invention. Suffice it to say that the conductor wires 78 may separate from 
the plug member upon being subjected to a generally axial pulling force 
greater than the strength of the connection between the wires 78 and the 
plug member 220. Alternatively, the plug member 220 could be adapted to 
separate from a cooperating socket portion, not shown, upon separation of 
the coupling member 174 from the coupling member 194 in a manner to be 
described further hereinbelow. As shown in FIG. 5A, the conductor wires 78 
are preferably of sufficient length to provide a strain relief loop 221 
within the bore 160. 
Referring further to FIG. 5B, a frangible coupling is formed between the 
coupling members 174 and 194 by opposed shear pins 222 which extend in 
relatively tight fitting relationship within cooperating bores 224 and 226 
formed in the members 174 and 194, respectively. The pins 222 may be of 
predetermined diameter and material shear strength such that, in response 
to a predetermined axial pulling force tending to separate the member 174 
from the member 194, the pins 222 will fail in shear to permit separation 
of these two members. The force at which the pins 222 will shear off 
across an interface between the exterior cylindrical surface of the member 
194 and the bore 176 is predetermined to be less than the force which will 
provide axial separation or rupture of the tube 28 or the cable 70. 
Accordingly, in the event that the tool 71 becomes stuck in the wellbore 
18 during an attempt to move the tool "up hole", the connector 84 will 
separate at the connection point between the members 174 and 194 and the 
conductor wires 78 will fail in tension or pull out of the plug 220 to 
leave the connector member 194 in assembly with the tool 70 in the 
wellbore 18. In this event, the fishing neck 198 is exposed for engagement 
with a suitable fishing tool for eventual retrieval of the tool 71 
together with the connector member 194 and the nipple 208 in assembly 
therewith. 
As will be appreciated from the foregoing description, the coupling formed 
by the coupling member 170 and the head 184 provides for limited angular 
and rotational excursion of the tool 71 relative to the sub 136 whereby 
the tool may be allowed to generally center itself axially in the wellbore 
18 while being pushed or pulled threrethrough. More particularly, the 
arrangement of the present invention permits the tool 71 to avoid being 
forcibly displaced against the sidewall of the wellbore as the tube 28 is 
moved throughthe wellbore. In this way, any irregular portions of the 
wellbore sidewall surface will not be as likely to snag or impede the 
movement of the tool 71 as it is extended or retracted longitudinally 
through the wellbore. By extending the tool 71 into the wellbore 18 using 
the relatively stiff coilable tube 28, the tool may be moved within the 
wellbore without undergoing the "rubber band" effect of the tool extension 
member which is often encountered with tools which are merely suspended in 
the wellbore by the wireline cable itself. Moreover, it is not necessary 
to rely on gravity or other techniques to force the tool 71 deeper into 
the wellbore since axial extension of the tube 28 may be carried out 
through operation of the coiled tubing unit 32 to forcibly move the tube 
in either direction through the wellbore. 
Thanks further to the connector assembly 84, there is no substantial axial 
stress on the wireline cable 70 during operations of the tool 71. Those 
skilled in the art will further appreciate that various types of tools may 
be utilized in connection with the connector assembly 84 and traversed in 
and out of a wellbore using the coilable tube 28 and an electrical signal 
conductor extending through the tube. In certain types of perforating 
operations the fluid pressures encountered sometimes tend to propel the 
perforating tool axially through the wellbore after or during the 
perforating process. This problem is, of course, avoided with the use of 
the coiled tube 28 and the connector assembly 84 of the present invention 
as means for inserting, positioning and withdrawing a perforating tool 
with respect to a wellbore. 
A substantial length of coiled tube 28 may be modified to receive a single 
or multi-conductor armored cable such as the cable 70, preferably by 
uncoiling the length of tube in question and inserting the cable axially 
through the uncoiled length of tube using a pilot wire which has been 
propelled through the tube by a small piston or pig device, not shown, 
attached thereto and pumped through the tube with pressure fluid to draw 
the pilot wire through. The pilot wire may then be attached to one end of 
the cable 70 whereby the cable is pulled through the tube 28 until it is 
extending from both ends whereby it may be prepared for anchoring to the 
connector assemblies 69 and 84. In preparing the cable 70 for connection 
of the conductor wires 78 to the connector 220, for example, sufficient 
lengths of the armor filaments 79 and 80 are removed to permit extension 
of the conductor wires 78 from the plug 106 to the plug assembly 220 
through the passages formed in the nut 152, the coupling members 170, 174 
and 194 and the nipple 208 and with sufficient slack to form the strain 
relief loop 221 and to permit angular excursion of the coupling member 170 
and the connector body 174 relatively to the sub 136. If a centralizing 
device is used in connection with the tool 71, the flexible coupling 
formed by the members 170 and 184 will permit substantial alignment of the 
tool, generally co-axial in the wellbore. 
The connector assembly 84 may be made up after insertion of the lower end 
of the tube 28 through the stuffing box 26 by attachment of the sub 136 to 
the tubing, extension of the cable 70 through the sub, preparation of the 
cable for anchoring within the sub, as well as extension of the conductor 
wires 78 through the respective connector parts described in conjunction 
with drawing FIG. 4. The pins 222 would be selected in accordance with the 
desired maximum axial force to be exerted on the connector assembly before 
shearout of the pins to prevent failure of the tube 28 and the cable 70 at 
some point uphole from the connector assembly 84. The tool 71 would then 
be connected to the lower end of the connector assembly 84 and inserted 
into the wellbore through the lubricator 24. The centralizer 148 could 
also be connected to and journaling the sub 136 by bolting the centralizer 
halves 150 and 152 together in surrounding relationship to the shank 
portion 137, all of this work being carried out through the lubricator 24 
in a conventional manner known to those skilled in the art for installing 
or inserting downhole tools through a conventional wellhead. The tube 28 
can then be extended into the wellbore 18 for positioning of the tool 71, 
as desired. 
If fluids are to be injected through the conduit 52 and the tube 28, 
suitable fluid flow into the wellbore 18 may be obtained through the 
passages 146 during various operations which can be carried out depending 
on the type of apparatus or tool connected to the lower end of the 
connector assembly 84. Referring to FIG. 8, for example, there is 
illustrated a deviated well, generally designated by the numeral 310, 
which is formed by a well casing 312 to provide a wellbore 314. In the 
arrangement illustrated in FIG. 8, the casing 312 is ready to be 
perforated by a perforating tool, generally designated by the numeral 316. 
The perforating tool 316 is connected to the connector assembly 84 at the 
distal end of tube 28 in essentially the same manner that the tool 71 is 
connected to the connector assembly as illustrated in FIG. 5b. The tool 
316 is typically provided with suitable centralizing arms 318 for 
centering the tool within the wellbore 314. 
In many wellbores, at the time perforating operations are to be carried 
out, fluids are already present in the well from one source or another. It 
is desirable during some perforating operations to displace liquids which 
may include debris and other contaminants up the wellbore a distance clear 
of the perforating gun or tool and to effectively lower the bottom hole 
pressure just prior to firing the perforating tool. In the arrangement 
illustrated in FIG. 8, the tube 28 has been inserted into the wellbore by 
the injection unit 32 and gas has been pumped into the wellbore 314 to 
displace liquid 324 up the wellbore to a point substantially above the 
tool 316 so as to prevent adverse effects of the liquid 324 during 
perforating operations. Thanks to the arrangement of the connector 
assembly 84, fluid may be pumped down through the tube 28 and into the 
wellbore 314 in the vicinity of the tool 316 by way of the passages 146 
and the nominal space provided by clearance between the shank 137 and the 
opposed sections of the centralizer assembly 148. 
Other methods and applications which can benefit from use of the connector 
assembly 84 include wellbore inspection processes utilizing wellbore 
imaging or televiewing equipment connected to the connector assembly 84 in 
place of the tools 71 or 316, for example, and wherein a relatively clean 
homogeneous liquid is preferably injected into the wellbore to provide a 
suitable transmission path for signals which generate images of the 
wellbore surface using such imaging apparatus. 
Those skilled in the art will recognize from the foregoing description that 
improved apparatus and methods for positioning wireline or similar 
electrical cablecontrolled tools in a wellbore have been provided by the 
present invention. Various substitutions and modifications may be made to 
the specific embodiments described herein without departing from the scope 
and spirit of the invention as recited in the appended claims.