US2135167A - Swab device for wells - Google Patents

Description

Nov. l, 1938. w. J. CAMPBELL SWAB DEVICE FOR WELLS Filed May 27, 1957 INVENTOR CAMPBELL ATTORNEY WILLIAM J.

Patented Nov. l, 1938 PATENT OFFICE swan DEVICE Eon WELLS William J. CampbelLNew York, N. Y., assigner to Petroleum Machinery Corporation, New York,- N. Y., a corporation o! New York Application May 27,

3 Claims.

This invention relates to swabs, more particularly to swabs intended and adapted for use in the cleaning of wells, such as oil wells, brine wells, water wells, and the like.

In the drilling and operation of wells having casings therein, it is necessary at various times "to clean the well from accumulations of muck, dirt, sand, gummy materials, and the like. For this, purpose it has been customary to provide a. swabbing device consisting of a swab with suitable ports, said swab being connected to a cable or the like and lowered into the well. In the downward movement, a valve or the like is opened allowing the uid to rise above the swab, thereby allowing the swab to descend into the well. When the lower end of the well is reached, the -motion is reversed, the valve closes and upon the raising of the swab, the iiuid in the well is pulled out.

Various types of swab for this purpose have been used, but principally they are unsatisfactory from a number of standpoints. Especially in wells which are of considerable depth, the time consumed in lowering the swab is a substantial factor and none of the prior art swabs were capabl'e of high speed operation. Many of the'swabs were delicate in construction, had valves and springs which easily clogged or became stuck. and thus they were quite unsatisfactory. Most of the swabs were stationary, relying upon valves which were intended to open and close at certain points in the operation, but such valves corroded, became stuck, would not close and otherwise were unsatisfactory.

It is among the objects of the present invention to obviate the diculties encountered with prior swabs and to provide a device which may be lowered intothe bottom of a well at a high speed, which will offer a minimum of resistance 40 to the iiow of uid through the same, which is sturdy and simple in construction, and which is self-cleaning.

In practicing the present invention, I provide a swab consisting essentially of a mandrel, said mandrel being iiuted. Closely surrounding the mandrel is a swab element consisting of a sleeve with a rubber swab held thereon. The sleeve ts closely on the mandrel with suiiicient clearance so as to allow the same to move readily up and down. When in the lower position, the sleeve seats upon a washer or the like to prevent the ilow of fluid down through the same, and in addition, there is a substantial distance between the lower end of the swab and the point. of termination of the utes. When the swab is vin the 1937, serial No. 145.005 (ci. 10s-zas) upper position on the mandrel, the ilutes extend 'from' a substantial distance below the bottom of the swab toV a substantial distance above the top of the swab,l thereby inducing a streamline unobstructed flow of the fluid under the swab Vand through the iiutes.

The uted portion is of a substantial length, being considerably longer than the swab and usually at least 50% longer. Thereby, there is exposeda considerable surface of the ilutes so that any muck or dirt which may have become packed into the utes, wil-l become readily loosened and removed. f

In the accompanying drawing, 'constituting a part hereof and in which like reference charac# ters indicate like parts,

Fig. 1 is an elevational view of a swab madeA in accordance with the present invention, some parts being shown in section, the swab being shown in the lower position;

Fig. 2 is a fragmentary view similar to Fig. 1, showing the swab in its upper position; and

Figs. 3, 4 and 5 are cross-sectional views of the mandrel showing various forms of flutings which may be used.

With reference to the drawing, the head I of the mandrel is formed with a. reduced portion 2 constituting a shoulder and a dependent mandrel 3. The lower end of the mandrel is formed with a threaded portion 4 and a nut 5 fits thereover, said nut having a. seat for the reception of a washer 6. The mandrel .islformed with a series of flutes 1 extending from a. point 8 in the head I and terminating at a point 9 which is a substantial distance above the end of `the mandrel, and leaving a. portion Ill of circular cross-section without any utes.

The swab itself lits fairly closely to the mandrel 3 andconsists of a sleeve I I, usually of steel or the like, having both ends threaded and having nuts I2 and I3 thereon. Said nuts have reentrant portions I4 and I5, respectively for the reception of the ends of the rubber or other swab I6. A series of openings I1 in the sleeve allow for equalization of pressures on both sides of the swab.

The upper end of the head I is provided with a alanis-r tend from below the swab to a pointabove the as nbre,rubber, leather. tin, lead and the like.

The washer may be omitted and a ground .steel swab. a flow of fluid is induced between the flutes 'I in a practically straight line, parallel to the line of motion of the sw'ab and therebythe fluid, ilowsin a streamline and without obstruction or hindrance. This is of extreme importance, especially in deep wells, as it allows the quick lowering of the swab into position.`

Upon-the upward movement, the swab takes the position shown in Fig. l, with the nut 'Il in engagement with the washer I, sealing oi! the portion above the swab from that below, and insur- A ing that the column of fluid above the swab will be raised. If, however, the sealing is not perfect by reason of the accumulation ofmaterial, there is a further seal due to the uniluted portion III of the mandrel I and the vclose flttingof the sleeve to the mandrel, whereby the slection between the end l of the uted portion and the bottom of the swab acts as a secondary seal. While in the` lower position, the upper 4portion of the mandrel ,l is exposed to' the fluid so that any dirt that has accumulated within the ilutes will be cleared away. Similarly, when the swab is in the position shown in Fig. 2, the lower ends oi the flutes are exposed and are similarly automatically cleaned.

In Fig. 3 I have shown`a slight modification of the mandrel, which consists of two portions I9 between'which there is a reentrant curvature 2 0, thereby forming two flutes; of very substantial.

` cross-sectional area, allowing a relatively large stream of fluid to pass over the same. In Fig. 4

there is shown still another modification in which three extensions 2 I are formed with reentrant portions forming the desired passageways. In Fig. 5, there is shown a mandrel 22 having six such flutes for the same purpose.

Although I have described my-invention setting forth a few embodiments thereof, said embodiments are intended to illustrate the many variations which are possible in the physical construction of the device. The head of the mandrel need not be formed as shown in the drawing and the threaded portion I8 may be omitted and in place of Vthe same, other means for securing the mandrel to the operating mechanism may be provided. Various numbers and shapes of ilutes may be provided other than those herein specifically described. One of the nuts I2 and I3 may be made as a unit with the sleeve and other means than shown in the drawing may be used for securing the rubber swab to the sleeve. The swab itself may be made oi' other materials than rubber,` although the latter' material is preferred. The holes I1 in the sleeve may be omitted and the washer 8 may be made of various materials, such seat may be substituted therefor. The spacing between the mandrel and the sleeve maybe varied within wide limits.

' It is essential for operation where a small diameter tube is used, to have the swab Il in close contact with the sleeve II to take upa A and the scope of the invention is not to be limited except by the character of the claims appended hereto.

What I claim is:

l. A swab device for wells comprising a uted mandrel, an enlarged head at the upper end thereof, a swab fitted on said mandrel to allow relative movement thereof on said mandrel, said swab having an inner sleeve of substantial length fitting closely around said mandrel, a stop member to limit the downward movement of said swab, said mandrel being free from uting for a substantial length above said stop member and cooperating with the lower inner portion of said sleeve to provide a seal.

2. A swab ldevice for wells comprising a iluted mandrel, an enlarged head at the upper end thereof, 'a swab fitted on said mandrel to allow relative movement thereof on said mandrel, said swab having an inner sleeve of substantial length fitting closely around said mandrel, a stop member to limit the downward movement of said swab, said head limiting the upward movement thereof, the fluting extending into said head,'the fluting terminating short of the lower end of said mandrel so as to provide aseal between said lower end and said sleeve for a substantial height.

3. A swab device for wells comprising a iiuted mandrel, an enlarged head at the'upper end there- WILLIAM J. CAMPBELL.

Images