US2724440A - Method of disassembling pipe sections in a well - Google Patents

Description

Nov. 22, 1955 1.. K. MOORE 2,724,440

METHOD OF DISASSEMBLING PIPE SECTIONS IN A WELL Filed Aug. 15, 1952 Z fill/195M512 K. #0025 it INVENTOR P Prz kwwpw w 9m ATTORNEY5 2,724,440 Patented Nov. 22, 1955 United States Patent OfiFice METHOD or DISASSEMBLINGPIPE SECTIONS I A WELL Lawrence K. Moore Natchez, Miss. Application August 15, 1952, Serial No. 304,470

1 Claim. Cl. 166-46) This invention relates to processes of methods for assembling or disassembling a pluralityof pipe sections cooperating to make up a string of pipe. More particularly, theinvention has'reference to a process of the type stated wherein fluid pressure is employed advantageously to facilitate the assembly ordisassembly of the pipe.

The invention can be particularly used to advantage in oil, gas, or water well operations, but as will become apparent from the description to be provided hereinafter, the inventive process can also be used in stringing pipe across streams, rivers, etc., as well as for unscrewing pipe in pipelines extended above ground.

In showing, hereinafter, how the process can be carried out, the illustration and description will be confined to the showing of a string of pipe in a well, such as an oil well. It will be understood, however, that this showing is offered purely by way of one example of a length of connected pipe sections to which the process can be applied, and it is not intended that the showing be restrictive of the uses to which the process might be put, except, of course, as necessarily required by the appended claims.

It is a common occurrence, in oil, gas, or water well operations, for a string ofpipe to become stuck at a location spaced a substantial distance from the surface of the ground, and heretofore, the disassembly of the unstuck or free portion of the pipe, from that portion which is stuck, has been attended by substantial inconvenience and loss of time. The common practice is to lower explosive to the point at which the pipe is to be backed otf. The explosive is then detonated to break the pipe.

. The broad object of the present invention is to provide an improved method of assembling or disassembling pipe, which will not necessarily require that successively following pipe sections be threaded or unthreaded into and out of engagement with one another, at each and every joint and which, further, will not require the use of explosive in connection with the removal of stuck pipe.

A more specific object is to devise a process of the character referred to wherein a fluid pressure can be employed to advantage, in such a manner as to permit joint rotation of all the connected pipe sections that are free to rotate, relative to the stuck pipe section immediately therebelow, the process being adapted to permit the connected, free pipe sections to be removed bodily from the hole in little more time than is presently required to unthread a single section relative to another section to which it is connected.

Another object of importance is to provide a process or method of the type stated which will permit the use of conventional parts of well equipment, thus to reduce substantially the expense involved in carrying out the process.

Another object is to provide a method or process of assembling or disassembling pipe which will be simple,

effective in practically all cases, and. capable of being carried out by a minimum number of workers.

Still another object of importance is to provide a process of the type stated in which any pressure fluid, such as air, steam, or water can be used.

Other objects will appear from the following description, the claim appended thereto, and from the annexed drawing, in which like reference characters designate like parts throughout the several views, and wherein:

Figure 1 is an elevational view, in which parts are broken away and other parts are shown in section, showing a string of pipe ready to be disassembled through the medium of the process constituting the present invention; and

Figure 2 is a fragmentary sectional view through a section of said pipe and through a pressure plug used in carrying out the inventive method.

The reference numeral 10 has been applied in the drawings to designate a plurality of elongated pipe sec;

tions, adjacent sections being threadedly connected to coupling sleeves 12.

This, considered per se, is a conventional showing,

The reference letter A has been applied to a stratum in which a portion of the string of pipe defined by the pipe sections 10, is stuck, and the reference letter. B

has been applied to a stratum immediately thereabove in which another portion of the pipe string is free to rotate. Heretofore, in such an eventuality, those pipe sections extending through the material B to the ground surface are detached in successive, descending order, and as will be appreciated this is a time consuming, laborious operation, this being particularly true when the string of pipe comprises a substantial number of pipe sections.

As is usual, the uppermost section 10 has. threadedly engaged therewith a head 14, provided with an inlet check valve 16 and a pressure gauge 18. Additionally, the head is providedwith a center opening at its upper end, receiving a gland or stufling box 20. All this is conventional, and as Will be noted, the process constituting the present invention is such as to permit its applica tion to these conventionally formed and conventionally connected parts of a string of well pipe.

At C I have designated one of the coupling sleeves 12 connected threadedly to the upper end of the uppermost pipe section 10 of those sections that are stuck. In accordancewith the process constituting the present Attached to the lower end of the line 22 is a cup-like;

plug or packer 24, the skirt of said plug being disposed in scalable, wiping contact with the inner surface of the string of pipe.

The plug 24 is dropped downwardly within the string of pipe until it is disposed immediately above the coupling 12 located at the point C. This arrangement is shown in Figure 1.

As a next step in carrying out the process, the string of pipe is filled from the plug 24 to the head 14 with any suitable pressure fluid, such as air, steam, or water.

The gland or stufling box is then tightened against the head 14to an extent suflicient to prevent leakage of the pressure fluid through the gland itself, or through the opening of the head 14 in which the gland is mounted.

The next step in carrying out the processis to apply fluid pressure with any conventional pump, not shown,

various factors, such as the diameter and thickness of the pipe sections 10.

As will be noted, there will now be defined a pressure s am er. between. p g an he d he p s u within said chamber is such as to cause that portion of the string or pipe extending between the plug and head to become rigid, to such, an extent as will effectively prevent any pipe section above the plug 24 from being unthreaded from a coupling sleeve 12 attached thereto.

This result obtains by reason of the fact that there is greater pressure within the aforementioned pressure chamber, than there is exteriorly of said. chamber, said greater pressure causing the threads, of the pipe sections bounding the chamber to be expanded against their associated couplings 12. This causes, these particular sections, to beheld in engagement with their associated couplings far more tightly than they would be were there no pressure inside the pipe string. In other words, there is established abnormal frictional, contact between the threads of a particular or selected group, of pipe sections so that none of ,the, individual sectionsthereof will rotate relatively one, to the other when the selected or particular group of pipe sections are rotated as a unit.

However, below the plug 24, the pressure within the string of pipe is no greater than the pressure outside the pipe, or is, at least, substantially less than the pressure within the pipe above the plug. When the process has been carried out to this extent, it is then necessary only that the uppermost pipe section 10, to which the head 14 QO lnected, be rotated. This will cause all the pipe sections down to and including that in which plug 24 isdisposed to be rotated as one. Thus, these several pipe sections will be immediately disconnected from that coupling 12 disposed. at the location C, thus to cause thestring of pipe to be separated immediately at the proper point. The free pipe sections, that is, those pipe sections above the upp rmost section disposed in stratum A, are now removed readily from the hole, and can be individually disconnected above ground as they are lifted. This operation, as will be appreciated, is far more simple and is carried out with substantially greater facility, than the conventional method of unscrewing successive pipe sections at ever-increasing depths within the hole.

From the foregoing, it will be evident that there has been. provided a method of disassembling from a string of threadedly connected pipe sections, a selected group of pipe sections, the method including introducing fluid under pressure into the selected group of pipe sections to establish abnormal frictional contact between the threads of the selected group of pipe sections and then rotating said group of pipe sections in a direction to uncouple it from the entire string of pipe sections. As previously pointed out, it is the abnormal frictional contact between the threads of the selected group of pipe sections that maintain the separate group as a rotatable unit so as tov uncouple h e ed oup fro he s n p p ct n t he. desired location since the group of pipe sections to be rotated as a unit is capable of predetermined selection, and when the selected group of pipe sections is rotated in a direction to uncouple it from the string of pipe sec-. tions, i t will be apparent that the next adjacent pipe section to the one end of the selected group to which it has a threaded engagement will not have'this abnormal pressure established by introducing fluid under pressure into the selected group of pipe sections so that the threaded con-. nection at this point will be uncoupled in preference to any of'the pipe sections in the selected group.

I believe it will be apparent that the process. can also be employed advantageously to unscrew pipe if a seatis installed in the pipe at a predetermined depth, which seat would 'hold a drop plug instead of a plug loweredthrough the string of pipe on a w-i-reline 22. In such an instance,

, 4 if the string of pipe becomes stuck and the pipe is to be disassembled at the location C, the plug can b e dropped downwardly inside the pipe, gravitating freely therein. Weights can be associated with the plug if desired, to assist the gravitational movement thereof. The plug would, in this instance, travel down the pipe until it lodges in the seat, after which pressure; is applied to the inside of the pipe above the plug in the manner hereinbetore described.

This, I believe, is sufiiciently obvious as not to require special illustration herein, it being believed. that it is well within the skill of those experienced in this art to provide a seat of the type stated;

It is also thought apparent that the process described herein could be used not only for disassembling pipe, but for assembling pipe, it being clear that a plurality of tln'eadedly connected pipe sections can be formed into P s re a in. he m nn r her i e ore de cr be and rotated asone relative to. a pipe section with which they r t be s s t ay n t d ha the RIQC c s be ed ut in a s mb ng o sa emhlins p p in P p ne above ro n h et e c ndit on a e such as to preclude ordinary assembly or disassemhly methods. Still further, the process can be employed ad; vantageously in sending; pipe across, streams or rivers, under conditions in whichthe, body of water to be crossed prevents the use of ordinary assembly ordisassembly. methods.

Ot ses. I e e m ysge hemselv It s. l e e ha he n nti ni not nec s rily confined to the, specific use. r uses thereof described e, s nce tmaY e t liz d f ny Purpo e to ich it may be suited. Nor is the invention to be necessarily limit to he. p fi s ru t ll s ra ed and. escribed, since such construction is only intended to. be illustrative ot the principles of operation and the means presently devised to carry out said principles, it being sidere t a he inve on. c mpr he ds ny minor hange in on tr c ion h t may p rm tt d t in. t e scope of the appended claim.

What is claimed is z The method of; disassembling from a string of threadedly connected; pipe, sections disp in a Wel a selected r up n ne. sec i ns. which mp is mo n a fluid seal downwardly through said. string to a selected loca tion' adjacentthe, lower end of; said, selected g oup... ntrou in and. m intaining fluid under p ssure. in s id selectedgroup above; the, seal to cause an increased frica ionalmn cti pon t e hr a onne g n ivi u l Pipesections of the selected group and to prevent rotation thereof; relative. t one; another, and, rotating the selected erc p Qtn p sec i ns-asaw it. in a. direction o. o p it rom. the s rin Refer nces-.011. in the. fil of. h s pat n UNITED. STATES. PATENTS

Images