US 3532163 A
Description (OCR text may contain errors)
United States Patent  Inventor John H. Ecuer Lafayette, Louisiana  Appl. No. 784,777
 Filed  Patented  Assignee'  AUTOMATIC PASSAGE CLOSING MEANS FOR WIRELINE TOOLS 2 Claims, 4 Drawing Figs.
 U.S. Cl 166/53, 166/84, 254/173, 277/28, 277/73  lnt.Cl E2111 33/02, F16j 15/18  Field ofSearch 166/53, 70,
75, 77, 82, 8487, 224; 277/73, 28,103; l37/5l55l5.7: 251/1: 254/]73tlnquired) 3,212,581 10/l965 Marshall 166/84 3,375,013 3/1968 Grantom 277 73x 3,424,247 1/1969 Lee l66/75X Primary Examiner-Marvin A. Champion Assistant Examiner-Jan A. Calvert A [tor/10 5 Paul F. Hawley and John D. Gassett ABSTRACT: One way of servicing oil wells is by the so-called wireline method. A tool is suspended at the lower end of a cable which passes through what is commonly called a lubricator. A lubricator and other equipment including pack-off assemblies are mounted on the top ofa well assembly which permits the cable to pass from a power drum on the surface to the tool inside the well bore without losing fluid to the atmosphere. However, should the wireline break, fluid is forced out through the passage where the wire was until such time as the passage is closed. In accordance with the main embodiment of this invention, a sensor means is provided to sense tension on the line. This sensing means is connected to means operative to close the passage through which the line had been should the sensor encounter no tension on the line.
Patented Get. 6, 1970 3,532,163
Sheet 1 of2 FIG 2 PACK OFF ASSY I (OF F|G.2) I22 CHECK VALVE I42 v (OF FIG. 3) I20 I II4o I I-I3o HYDRAULIC SLIPS r I OF FIG. 4 40 2 .& |24 r H2 36 L I Q II II 22 24 H I IIO JOHN H. ECUER INVENTOR.
ATTORNEY Mil l6 15% 5? AUTOMATIC PASSAGE CLOSING MEANS FOR WIRELINE TOOLS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to oil well equipment and pertains more particularly to wireline operated tools which are injected through a pressure seal into a high pressure well.
It is often desirable during the operation of a high pressure well to introduce therein on a wireline various tools such as pressure or temperature recorders, perforators, etc. Insertion of these devices is accomplished generally by first installing a lubricator on top of the well head. A lubricator typically includes a length of pipe placed above the master valve on the christmas tree or well head. This pipe has a sealing element such as a stuffing box at the top thereof. With the master valve closed, the desired tool is placed in the lubricator and attached to the wire after the wireline has been passed through the stuffing box. This complete unit can then be attached to top of a christmas tree by a sealed union connection. This makes a closed system. The master valve is then opened and the tool lowered into the well. These tools can be, as mentioned above, rather small recorders or they can be relatively long lengths of cylindrical pipe containing various operational features thereon.
2. Problem Involved There are many very good lubricators commercially available for use with many different types tools. In the past most of these wireline tools have been inserted into wells drilled on land. If the line supporting the tool should break, there is, of course, a fishing job for removing the tool from the well. There is another problem involved, which is the escape of a small amount of hydrocarbon through the passage through which the line had passed until the main valve can be shut off. The amount of gas passing through the relatively small passage is not necessarily much ofa problem on land.
However, it is contemplated that many wells will be completed on the ocean floor. That is, the wellhead will be submerged several hundred feet under water. For small remedial work the well will be serviced by water-tight, aircontaining capsules which are lowered to the wellhead and sealingly fit thereto. The wireline lubricator will be inside'this capsule. There will also be human operators inside these capsules. It is readily apparent then that even a small amount of hydrocarbon escaping into the service capsule can be disastrous. It is an object of this invention to provide means whereby the escape of hydrocarbons from the lubricator is eliminated or at least greatly minimized.
BRIEF SUMMARY OF THE INVENTION This invention concerns a system which immediately closes the passage for a line in a wireline lubricator if that line is suddenly removed from the passage without warning. In a wellhead lubricator there is ordinarily a stuffing box through which the line passes and hydraulic pressure is placed on the packing so that it exerts a sealing contact with the line. However, pressure is limited so that there will not be too great a frictional force exerted on the line. In a preferred embodiment a tension sensor is in contact with the line above the stuffing box. A high pressure hydraulic fluid source is provided. A valve means is in a conduit connecting such source to the stuffing element. This valve is opened when the tension sensor senses a broken line which relieves the tension on the line. The high pressure hydraulic fluid then immediately forces the packing into the space which the line formerly occupied.
BRIEF DESCRIPTION OF THE DRAWINGS Various objects and a better understanding of the invention can be had from the following description taken in conjunction with the drawings.
FIG. 1 illustrates a lubricator and associated parts connected to a wellhead for use with wireline tools and shows the relationships thereto of the embodiments of FIGS. 2, 3 and 4.
FIG. 2 illustrates the preferred embodiment including a pressure sensor in contact with the wireline passing through the lubricator.
FIG. 3 illustrates a modification of a conventional pack-off to have a flapper valve for closing the inlet in the lubricator through which the line passes.
FIG. 4 illustrates a modification or improvement to be used in conjunction with the lubricator above the blowout preventers (13.0.?) to preventan elongated tubular tool from being blown out of the well.
Attention is first directed to FIG. 1 which illustrates apparatus to be added to the top of the wellhead for use when running wireline tools in the well. This includes a casing upon which a wellhead assembly 112 is permanently mounted. All the parts above the wellhead 112 shown in FIG. 1 are removable and are normally used only when running wireline tools in the well. This auxiliary equipment includes a wireline blowout preventer 114, a hydraulic slip section 116 (as shown in detail in FIG. 4), a lubricator section 118, a check valve section (as shown in detail in FIG. 3) and a hydraulic pack-off assembly 122 (as shown in detail in FIG. 2). These different sections are connected to the wellhead and to each other by quick connect unions 124, 126, 128, 130, and 142. A wireline 14 passes over support sheave 144 and goes to a power drum, not shown.
The operation of wireline equipment is well-known; however, a brief review here will be helpful. When it is desired to run a wireline tool in a well 110, the assembly as shown in FIG. 1 is connected by quick connect union I24 to the top of the wellhead 112. Quick connect union 140 is disconnected and the wireline is passed down through the hydraulic pack'off assembly 122 and extends out the low-er end thereof. The wireline 14 is then connected to a wireline tool, now shown, such as a perforator, which is to be run in the well. This perforator or well tool is elongated in shape and is placed inside lubricator 118. Then union 140 is made up. At this time the valve of wellhead 112 is opened, as are blowout preventers I14. Then the wireline tool is lowered into the well to perform its function. After the well tool has performed its function, it is drawn back up in lubricator 118 by pulling up on line 14.
When the tool has cleared blowout preventers 114, they are closed and the tool is removed from lubricator section I18. After all wireline tools have been run as desired and removed, wellhead 112 is closed and the assembly :is removed by disconnecting the union I24.
Now that the general equipment of FIG. 1 has been discussed, attention is directed to FIG. 2 which shows an improved hydraulic pack-off assembly 1220f FIG. 1 in detail. As can be seen in FIG. 1, this assembly is attached above the top of the lubricator. This hydraulic pack-off assembly includes a lower housing 10 and upper housing 12 and a wireline or line 14 which passes therethrough to a tool 16 at the lower end thereof. The line 14 passes through an upper packing 18 which is held in place by manual tightening of cap 20 which also has a passage for line 14. Upper housing 12 is sometimes filled with an oil through valved breather" conduit means 13.
The cable must be able to pass through the lubricator without permitting escape of high pressure gas or hydrocarbons from the well. A packing means 22 is provided in lower housing 10. Packing 22 is mounted in a cylindrical cavity 24 which is formed in plug 27 which is attached to housing 10. Packing 22 is held in cavity 24 by a piston-shaped member 26 which has a lower conical surface 28 which matches the upwardly facing surface of a packing 22. The force with which the piston 26 is pushed downwardly determines the pressure of packing 22. It is known that one does: not wish to have too much force between the packing and the line or else the friction will prevent the line from passing therethrough. Yet there must be sufficient force so that there isno leaking of fluid between the line and packing. A main piston 30 is sealingly fitted with seals 32 into the upper part of lower housing 10. Piston stem 33 extends up through the top of lower housing 10 and is provided with seals 35. There is thus formed an annular pressure cavity 34. Hydraulic fluid is provided to cavity 34 from high pressure source 36 through conduit 38 having valve 40 therein. Piston 30 is biased upwardly by spring 42. By a proper adjustment of the pressure of hydraulic fluid in cavity 34, the desired force of packing 22 on line 14 can be obtained. However, if this is all the force used, if line 14 should break, line 14 would drop downwardly through the packing 22 and the pressure on the packing would not be sufficient to close the vertical passage through which the line previously passed. This would permit the escape of fluid or hydrocarbons up wardly into housing 12. As pistons 30 and 26 have a passage therethrough, fluid would rapidly escape to the atmosphere until such time as the main valve were closed or packing 22 forced shut. On land this escape of hydrocarbons has not been considered to be a serious problem. However, if this leakage were in an underwater capsule, a small amount of hydrocarbons escaping thereinto would be very hazardous.
With my invention I provide means for detecting when line 14 has broken and for immediately closing the passage which line 14 had previously occupied before dropping down into the well bore. This includes a pressure sensor 44 having wheel 46 which is in continuous contact with line l4v As long as there is tension in line 14, wheel 46 and its arm 48 are held in a retracted position, in this case to the right. This holds valve 50 in a closed position. Arm 48 is biased in a direction toward line 14. If line 14 should lose its tension as would occur when it breaks, arm 48 would move to its extended position, thus opening valve 50. Valve 50 is in a conduit which connects a high pressure hydraulic source 36 through conduit 52 and 54 to cavity 34. When valve 50 is opened, the high pressure fluid immediately forces piston 30 and extension piston 26 downwardly to compress packer 22 sufticiently so that if the line 14 is no longer in packing 22, the previous passage through which the line passed is effectively closed. Thus the passage is closed before any appreciable amount of hydrocarbons can escape. As mentioned above, this is most important when the wireline operation is being performed in an underwater capsule. It is also rather important that no liquid hydrocarbons escape when the drilling platform is at sea as space there is rather limited and facilities for disposing of such waste are limited.
In some cases it is necessary to pull a wireline from the lubricator without the tool; for example, if the tool were stuck in the hole and the wireline had to be severed. Means for closing the passage through which the wireline is pulled is shown in FIG. 3. Shown therein is a check valve body having an upper section 60 and a lower section 62 as a part of union 140. Upper section 60 has compartment 66. Upper section 60 has a threaded section 61 for connection as a part of union 142, This lubricator has an upper passage or wireline port 64 through which a wireline, when the lubricator is in operation, passes. When the wireline is removed from passage 64, it is im perative that passage 64 be closed immediately so that any hydrocarbons which may be in chamber 66 and in the lubricator will be held there and not be permitted to escape. This is accomplished by providing a plug 68 closing passage 64. Plug 68 is attached to flapper valve frame 70 hinged to flapper pin swivel 72 and biased in a closed position. Plug 68 can be made of Teflon or nylon, for example. This flapper valve 70 rides against the cable when the line is in operation. However, once the line is removed, the flapper valve 70 rapidly closesv Attention is next directed to FIG. 4. In ordinary operations the vertical length of the lubricator determines the length of the tool which can be lowered or removed from a well bore. On land the lubricator can be made as long as the tool. In a subsea capsule and on certain small platforms the vertical length is limited. If the tool is longer than this vertical dimension, the tool protruding through master valve would prevent it from being closed. The tools can be made in sections. How ever, when the upper part of the lubricator is opened, the tool is apt to be blown out before the sections can be disconnected. Tool extends through a regular wireline B.O.P. (but not shown in FIG. 4). However, the B.O.P. cannot always hold the tool against high well pressure. Thus, making the tool in sections would be of no benefit.
However, by the use of the embodiment of FIG. 4 the taking out of the tool by sections can be accomplished. I provide other means for holding the tool in place. A housing 86 surrounds tool 80 and has a vertical passage therethrough. Slips 88 are provided therein and the teeth are shaped or oriented so that the tool 80 can move downwardly but not upwardly. An annular cylinder 90 is provided in the lower end of housing 86 and is provided with an upper sloping shoulder 92 which mates with the downwardly facing shoulder 94 of slips 88. Seals 96 are provided between piston 90 and the housing 86. An annular cavity 98 is provided in the lower end of housing 86 and fluid pressure acts upwardly on shoulder 100 of piston 90 to force it upwardly. Hydraulic fluid is provided through port 102. The application of hydraulic fluid in cavity 98 forces annular piston 90 upwardly and causes slips 88 to engage tool 80. When the pressure is released, annular member 90 is forced downwardly by springs 104. The device of FIG, 4 can be located just below the B.O.P. 114 of FIG. I as well as above.
The above described invention has been explained in detail. However, various modifications can be made therefrom without departing from the spirit or scope of the invention.
1. ln an apparatus for use with a wellhead and having a vertical passage therethrough for a cable and a compressible packing means in said passage having an opening therethrough for sealingly contacting said cable and closing said opening in response to the application of compressive force to said packing means, the improvement which corn prises:
sensor means for sensing the tension on said cable, said sensing means to be in one position when the cable is taut and in a second position when tension is removed from the cable; and
second means responsive to the second position of said sensing means to add compressive force to said packing means.
2. An apparatus as defined in claim 1 in which said second means includes a source of high pressure fluid:
a piston means for compressing said packing means; and
a conduit connecting said source of high pressure fluid to the power side of said piston means and a normally closed valve in said conduit operative to open when said sensing means is in its second position.