US2155370A - Well liner - Google Patents

Description

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'Patented Apr. 1s, 1939 UNITED STATES .PATENT OFFICE WELL LINER California Application July 2.7, 1936, Serial No. 92,800

3 Claims.

This invention relates to the testing and producing of wells and relates more particularly to a well liner useful in such operations and to a method for recovering the same from the well.

A general object of this invention is to provide a practical improved well liner and a rapid, inexpensive and commercially practical method for handling and recovering the same.

When a well is to be tested or produced it is customary to arrange a tubular perforate liner in the open or uncased portion of the well to prevent caving and sanding up of the well. Such liners are usually made up of a plurality of sections of steel pipe or tubing of standard length connected by right-hand threaded steel couplings. The ow conditions and other conditions in the well often cause the sand and formation to tightly pack about the liner. A liner thus sanded in a well is often frozen or immovably caught so that it cannot be removed as a unit. Accordingly, when it is desired to remove a liner from a well to permit deepening of the well or to carry on other operations it is necessary to resort to costly time consuming fishing operations. Owing to the length of the sections of a typical steel liner and to the character of its couplings it is usually impossible to unthread the sections one from the other in the well and it becomes necessary to cut the liner and remove it from the well in small fragments or parts. As the portions of the liner thus cut free in the Well must be removed one at a time, the recovery of a liner from a Well in the usual manner is a very costly and time consuming operation.

It is another object of this invention to pro' vide a well liner that is fabricated so that it may be disassembled in the well and recovered from the well without resorting to expensive cutting and fishing operations.

Another object of this invention is to provide a well liner so constructed and formed that its sections may be disconnected in the well for individual recovery or for recovery in assemblies of two or more connected sections without resorting to cutting, ripping or similar fishing operations.

Another object of this invention is to provide a Well liner fabricated of a plurality of relatively short sections that may be individually rotated and thus successively unthreaded one from the other for recovery from the well under very adverse conditions where the liner is so tightly sanded or caught in the well that it would be impossible to unthread the individual long sections -of a typical liner.

Another object of this invention is to provide a well liner of the character mentioned in which the sections are connected by threaded couplings formed of a material that is such that the threads will strip or fail in the event that it is found desirable to jar or otherwise manipulate the liner to free its sections or groups of sections for 4removal from the well without unthreading them.

Another object of this invention is to provide a well liner of the character mentioned that is simple and inexpensive and that may be readily constructed in any desired length.

Another object of this invention is to provide a simple rapid method for recovering a liner from a Well in unmutlated sections or assemblies of sections.

Another object of this invention is to provide a method for recovering a liner from a well that effects the separation or disconnection of the liner sections in the Well without resorting to cutting,

ripping, blasting or shooting of the hner.

A further object of this invention is to provide a method for recovering a liner from a well that is very rapid and does not endanger the well or any of the Well equipment.

The various objects and features of our invention will be fully understood from the following detailed description of a typical preferred form of apparatus and manner of carrying out the method of the invention, throughout which description reference is made to the accompanying drawing, in which:

Fig. 1 is a longitudinal sectional View of the lower portion of a well illustrating the liner of the present invention being set therein by a setting tool. Fig. 2 is an enlarged fragmentary longitudinal detailed sectional View taken as indicated by line 2--2 on Fig. l. Fig. 3 is a transverse detailed sectional View taken as indicated by line 33 on Fig. 2 and Fig. 4 is an enlarged longitudinal detailed sectional view of a portion of the well illustrating the recovering string and tool extending into the liner.

It is believed that the method of the present bers for lining the open portion of a well. 'I'he sections I may be formed of steel or other suitable material and are of such diameter that they properly flt the open portion ofthe well W with the necessary clearance. In practice thel several sectionsA I0 may be of the same diameter and may be'of the same length; It is a feature of the invention that the liner sections I0 are relatively short being only a few f eet in length. The liner sections I0 being relatively short present only limited circumferential surfaces against which the sand and caved earth formation may pack and the sections are proportioned so that they may be individually rotated under the mostradverse caved and sanded up conditions. 'I'his proportioning of the liner sections I0 whereby they may be individually rotated when the liner is tightly sanded in the well W is very important as it provides for the individual disconnection of the sections I0 in the well as will be subsequently described. It is to be understood that the liner may embody as many sections I0 as necessary. In other words the liner may lbe constructedof any necessary number of sections I0. 'I'he liner sections I0 are perforated to admit the well iiuids. 'Ihe liner may be perforated prior to its introduction to the well or may be perforated when set in the well. In the particular case illustrated in the drawing, the liner sections III are provided with a multiplicity of longitudinally and circumferentially spaced slots I2 formed therein prior to the setting of the liner in the well. The slots I2 extend throughout the portion of the liner which passes through the producing zones of the earth formation. In practice the liner I0 may reston the bottom of the well and its upper end may extend into the lower end of the well cas. ing C.

'I'he couplings II are provided to connect the tubular liner sections I Il. In accordance 'with the invention the couplings II are threaded to the adjacent ends of the sections I0 to releasably or detachably connect the same. the invention the couplings I I are formed of aluminum or an aluminum alloy or other suitable material that has a substantial tensile strength and yet has a relatively `low shear strength so that threads out therein will fail or strip under substantial strain. Thus the collars or couplings II form frangible connections between the adjacent -sections I0 that may be released or broken in the event that the sections cannot be un- -threaded. As illustrated in the drawing the right-hand threads it may be preferred to provide the liner sections Ill and the couplings/II with left-hand threads. -This relationship be.- tween the threads of the liner and the threads of the recovering string facilitates the disconnection of the liner I0 without endangering the threads of the fishing string or recovering string.

In arranging or setting the liner of the present invention in the well W a suitable setting string S may be employed to run the liner through the casing C. VA releasable connection or setting tool may be provided to connect the upper end of theA liner with-the setting string S. The typical set- In accordance withting tool illustrated in the drawing includes a tubular adapter I5 threaded on the upper end portion of theuppermost liner section I0. The adapter I5 has longitudinal slots I6 provided with lateral branches I1. Vertical grooves I8 are ,provided on the interior of the adapter I 5 and extend oupwardly from the slot branches I1. The setting tool further includes a mandrel I9 threadedly secured to the lower end of the string S.A The mandrel I9 is adapted to enter the adapter I 5 and has lugs 20 for cooperating with the slots I6. When the liner is to be yrun into the well on the string S the lugs 20 are entered in the longitudinal slots I6 and cooperate'with the slots to secure the liner to the string. Following the proper arranging or setting of the liner in the well the string S may be manipulated to move the lugs 20 into the lateral branches II of the slots I6. The lugs 20 are moved through the branches l1 into the grooves I8. The string S is then moved upwardly to withdraw the lugs 20 from the grooves I8 and free the mandrel I9nfrom the adapter I5. The string S may then be withdrawn from the well leaving the liner in the set or operative povsition.

The liner may be set in the manner just described to remain in the well during a test of the productivity of the well or during a prolonged phase of the production of the well. The liner serves to admit fluid from the producing formations of the well to the lower end of the casing C and the fluids thus prgduced may flow to the surface or may be pumped from the well in the usual manner.

The method of the present invention is intended to facilitate the removal or recovery of the liner from the well W when it is desired to deepen the well or perform other operations in the well. The improved method of the present invention includes, generally, the engagement of the liner with'a recovering string, the application of rotation to the liner from the string for the purpose .of disconnecting the sections I0 of the liner, the removal from the well of a section I0 or a group of sections I 0, thus unthreaded, and if necessary the jarring or other. manipulation of the liner to break the threaded connections at the couplings II.

In accordance with the method of the invention a recovery string is connected with the liner for the transmission of force thereto to separate or disconnect its sections I0. The recovering string employed may be a string of tubing or pipe connected by threaded couplings. The threads of the recovering string are pitched in the opposite direction to the threads on the sections I and couplings II. For example, where the threads of the sections I0 and couplings II are lefthand threads, as described above, the threads of the recovering string are right-hand threads. The recovering string is provided with or carries a tool T to engage the liner for the transmission of force from the string to the liner. In practice a releasable overshot adapted for the transmission of both longitudinal forces`and rotative forces may be provided on the recovering string to pass downwardly over and engage about the liner. I

The particular tool T illustrated in the drawing is inthe nature-of a releasable rotary spear. Fig` 4 of the drawing illustrates the spear or tool T in its operativeposition within a section In of Vthe liner... The tool'l? embodies gripping parts or .l slips 22 having teeth for gripping the interior of the linertc transmit longitudinal force thereto which teeth are formed or provided with grooves to effectively transmit rotation to the liner. 'I'he spear or tool T is preferably such that it may be released at the will of the operator. As rotary releasing spears are well-known to those skilled in the art, the details of the tool T will be omitted from the present disclosure. The tool T is connected with the recovering string to turn therewith and to move longitudinally thereon.

In carrying out the first step of the method the tool T is run into the well on the recovering string and is entered in the liner. The tool T may be run to any desired point within the liner and actuated or set to gripits interior. 'I'he tool T may be actuated or set within the upper portion I of the liner and following its .actuation an up- 'iV strain may be placed on the recovering string in an attempt to bodily lift and recover the linerv from the well.A If the liner pulls free without placing an excessive o-r hazardous strain on the recovering string it may be recovered bodily from the well on the string without further operations. However, it may be found that the liner cannot be bodily withdrawn from the well in this manner in which event the tool T is released and is moved to another position in the liner. It may be preferred to position the tool T a point adjacent but some distance above the lower end of the line to apply a turning force to the luier. Following the setting or actuating of the tool T the recovering string is turned or put under a torque in a direction to unthread the threads I4 of the liner. In the event that the particular section I0 engaged by the tool T and the sections I0 above that section are free to turn or are relatively free so that the rotational force applied to the tool turns them, the application of the rotative force may unthread a thread I4 of the coupling I'I justV below the tool T, in which event a portion of the liner comprising several sections I0 may be freed from the remaining sections below the tool T. Following such freeing or unthreading of the assembly of sections I0 the recovering string carrying the tool T may be raised to withdraw the freed assembly of sections I0 from the well, the

tool T serving to connect the assembly of sections with the string. In this manner it may be possible to'recover a substantial portion of the line in one operation.

In the event that the above described attempt to unthread a portion of the liner fails the tool T may be released and moved to a higher position in the liner and then re-actuated to grip the interior of the liner. A turning force is then applied to the tool T through the medium of the recovering string in an attempt to unthread the section I0 gripped by the tool T and the higher section I0 from the remainder of the liner below the tool T. This second attempt to disconnect the liner IIJ may be successful, in which event the section or assemblies of sections Ill freed or unthreaded may be recovered from the well as described above. If the second attempt to disconnect the liner fails the tool T may be freed and moved to a higher position and then reset to again apply an unthreading force to the liner. In this manner the tool T may successively set at vertically spaced points to apply unthreading force to the liner. In some instances only the upper section I0 or several upper sections I0 may be unthreaded from the remainder of the .liner during the rst recovery operation.

The above-described operation of actuating the tool T and applying unthreading force to the liner to unthread a section i0 or an assembly of sections III and the recovery of the section or .sections thus freed is repeated until the entire diner is recovered from the well. It may be found that the portion of the liner remaining in the well, following the recovery of one or more sections III, is free to be pulled from the well in which event the said remaining portion may be bodily recovered with little dimculty. It is to be particularly noted that the sections I0 comprising the liner are short so that the aggregate locking or holding force exerted by the caved formation or sand on one section I0 may be readily overcome by the turning or unthreading force applied to any one section by the tool T. Becauseof this proportioning of the sections I0 the individual sections I0 or assemblies of sections Ill may be successively unthreaded and freed for removal from the well., 'I'he liner I0 may be entirely recovered from the well by merely employing the recovering string and the force applying and lifting tool T without endangering the recovering string and without cutting or destroying the liner.

, Under certain circumstances it may be found desirable or necessary to jar the liner or apply longitudinal force'to the liner either before, during or after the above described operations. For example, it may be found that the liner I0 is very tightly sanded in the well throughout its entire length or a substantial portion of its length, in which case it may be desirable to attempt to free or partially free the liner to facilitate the disconnection of its sections I0 in the manner described above. Further, it may be found that a certain section I0 or an assembly of sections I0 is very tightly caught in the well, making it dangerous or impractical to attempt to disconnect it by unthreading.

The method of the present invention provides forthe application of longitudinal force of the desired intensity and character to theliner to free it or partially free it and if necessary to release its threaded connections by brealing the threads thereof. The recovering string carries or embodies jars or a jarring tool J. 'I'he jars or tool J may be located above the force transmitting and lifting tool T. When it is desired to employ the jarring tool the recovering string is run into the well to enter the tool T in the selected portion of the liner. The tool T is then set or actuated and the recovering string is manipulated so that the jarring tool J imparts a jarring action to the liner. In mostinstances this jarring action will be an upward jarring action for the purpose of freeing the liner from the well or for shearing or breaking the threads of the couplings II. Any particular or selected section I0 of the liner may be engaged by the tool T for the application ofthe jarring blows by the jarring tool` J. The recovering string may be manipulated in a manner to effect the breaking or stripping of the thread or threads I4 of a coupling II to thus free a section IU or a group of sections I0 thatis caught in the well. 'I'hus the method provides for the freeing of a section I0 or a group of sections I 0 that could not be freed or disconnected by unthreading it from the remainder of the liner.

It is to be understood .that the jarring tool J I0 engaged by the tool .T maybe more readily i ing force'to a section -IU of the linerto strip they threads ill ofthe liner Il at the lower end of that particular section I0.

f 'I'he method ofthe present invention is capable of `eiecting the` recovery of the above-described liner'under practicallyY any circumstances. The

liner is formed or constructed to be easily lrecovered from the well by the method of the invention. The method'of the present` invention provides for the rapid recovery of a liner from the well without endangering any of the equipment and without destroying or mutilating the liner.

Having described only a typical preferred form of apparatus and manner of' carrying out the method of the invention, we do not wish to be limited'or restricted to the specic details herein set forth, but wish to reserve to ourselves any variations or modifications that may appear to4 those skilled inthe art or fall within the sco of the following claims:

Having described our invention, we claim:

1. A well liner comprising a plurality of tubular liner sections. threaded at the ends, and couplings threadedly connecting the liner sections and formed of a metal considerably weaker than that of the liner sections, each coupling constituting the sole means connecting adjacent liner sections whereby upon application of excessive strains to a liner section to remove it `from the well failure will occur at the coupling, thus detaching the liner section completely lfrom the remainder of the liner sections and permitting its removal.

2. A well liner comprising a plurality of tubular sections formed of steel, threaded at the ends, and an aluminum coupling for joining the sections end to end, said coupling having threads 'at each end for mating with the threads on the sections and adapted to rupture under a strain applied to the liner.

3. A well liner comprising a plurality of tubular sections threaded at the ends, formed of a material such as steel, and threaded tubular means formed of an aluminous material threadedly connecting adjacent tubular liner sections whereby the connections will rupture upon being subjected to an abnormal tensional or torsional strain.

ELWIN B. HALL. ARTHUR L. ARMENIROUT.

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