US975065A - Process for drilling and cementing wells. - Google Patents

Description

W. W. PEDDBR.

PROCESS FOR DRILLING AND GEMBNTING WELLS.

APPLIOATION FILED DBO.6,1909.

975,065. Patented Nov. 8, 1910.

U TE STTS CALIFORNIA.

.PROCESS FOR DRILLING AND CEMENTING WELLS.

Specification of Letters Patent.

Patented Nov. 8, 1910.

Application'led December 6, 1909. Serial'No. 531,508.

To all whom it may concern:

Be it known that I, WILMER W. PEDDER, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented new and useful Improvements in Processes for Drilling and Cementing Vells.

This invention relates to the drilling of Wells and is particularly applicable in the drilling of deep wells such as oil wells or gas Wells. In drilling wells of this kind it is customary to sink an outer casing to as great V a depth as possible and then to sink successive inner casingswhich are .concentric with the outer casing and enveloped thereb These inner casings extend successive y to greater depths, that is, the innermost casing will extend to the greatest depth, and intermediate casings to intermediate'depths. In sinking the casings it frequently happens that the earth on the outer sides of the casino-s will adhere or freeze at certain pomts andthis exerts a great resistance to the lowering or removal of the casings.

In accordancel with the present invention, I transform the outer casing into a jacket as soon as it is in place upon the introduction of the first inner casing, and seal the upper end of the annular space between this outer casing and the inner casing which is being sunk. Water is then circulated down the inner casing and. up the outer side of the inner casing. lVhen thi's Water arrives at the lower end of the outer casing, on account of the fact that the annular space is sealed above, it must pass up the outer side of the outer casing. In this way I maintain the entire lengt-h of the inner and outer casings free from earth adhesions on their outer *k side, and I proceed inthe same manner to ice of the inner casing.

.The invention consists in the process to be described more fully hereinafter and'particularly set forth in the claims.`

In the annexed drawing which fully illustrates my invention, Figure 1 is a vertical section showing the manner in which the apparatus is employed to keep the outer wall of the strings ofpipe clear to prevent its becoming frozen as the well is drilled.

Fig. 2 is a plan and partial section showing thedetails of the stutling box which constitutes a feature of the-apparatus. Fig. 3 is a diagrammatic view illustrating the manner in which the apparatus is employed-to cement around the pipe so as to seal or cut off a water stratum. Fig. 4 is a view similar to,Fig. 3 and showing the manner in which the apparatus is employed toiclear or scour a frozen part at an intermediate point or level of the string of pipe.

Referring more particularly to the parts and particularly to Fi 1 1 represents a string of pipe which is eing sunk in formlng a well. My apparatus comprises a'string 4 or shell 2 ofpipe formed in sections connected by screw couplings 3 and forming( a @i ljacket around the inner string 1. Th'isjac -is of sutciently large diameter to form an annular jacket space 4 as indicated, surrounding the casing 1. At thev upper end of the jacket 2 a stuing box 5 is attached by means of a suitable coupling 6. Thev bore ortion of this stuffing" box iameter as the bore of the 7 at the lower 1s of the same jacket 2, but the upper portion of the stuiling box is provided with a counter bore 8 of larger diameter, so that an annular shoulder 9 is formed on the inner side of the stuffing box. O11 this shoulder 9 rests a packing ring 10 which ring is formedin two sections 11 and 12 connected by a pivot pin 13. Diametrically opposite to the pivot pin these sections 11 and 1 12 present abutting faces 14 as shown in Fig. 2. Above the packing ring 10 a space is formed in which I place a soft vegetable packin is held in place by a g and 16 in the form of a. bushing which vis received in the mouth of the stuiiing boxy as indicated. This gland is held in place by a nut ring 17 which is screwed on to the upper end of the stuffing box, and this nut ring presents an inwardly projecting flange 18 which extends over the Lipper face of the land and retains the same', as will be readlly understood. vIn order to enable cement or waterto be introduced'into the space 4 between the jacket and the pipe string 1, I provide pipe connections 19 and 20 at each side of the stuifing box and either or both of these connections may be provided with valves' such as the valve 21. The jacket 2 is formed like an ordinary casing, that is, the sections are 15 and this packing` xdded one by one as the we11 is sunk. Re-

vabut against each other at diametrically opposite points as at 24. At these points openings are provided for lifting the gland out of the stuffing box by means of hooks. To thefupper end of the pipe string 1 a circulating head 27 of any suitable construction is attached. v

I shall now describe how to maintain the strings of pipe free from 'earth adhesion on the outer side in sinking a well in accordance with my process.

In forming a well an outer casing is sunk to a suitable depth by employing a circulating head in the usual manner. This outer casing forms the jacket 2 of my apparatus. After this outer casing is sunk by means of a circulating head .1n the usual manner the inner casing 1 is sunk to a de.-

' sired depth so that its lower end extends to Y any depth -below the lower end of the outer casing. In ractice it is customary to add sections to t e outer casing until the limitI of tensile strength of the casing is reached, then the inner casing is sunk and sections are added in a similar manner to the limit of the tensile strengthy of the inner casing, in this way the inner casing may' extend several thousand feet below the outer casing. After the outer casing has been sunk as far as possible and securely suspended, the stuifing box 5 is attached to itssupper end as indicated in Fig. '1, and the inner casing or vstring 1 of the pipe is sealed at the mouth of the outer casing by means of the stuiing box as shown in Fig. l. When a new section of the pipe string l is to be added, circulating head 27 is removed and, by means of a coupling'similar to the coupling 30, another pipe section is added. The pipe is then sunk -farther into the well and in order to enable the coupling (which is similar to the coupling 30) to pass the stuiiin box, I remove the ring* nut 17, the gland 6 and the packlng 15 together with the packing ring- 10. The shoulder 9 will of course permit the coupling to pass so that with these parts removed there is/no obstruction which would tend to prevent 'the assing of the coupling into the interior of t e jacket at the stuffing box. As soon as the coupling passes the shoulder 9 the parts of the stuffing box can be replaced so as to permit the drilling process to continue In orderl to keep the y p ipe string clear from the earth 31 at each side, water' is circulated down froml the circulating head throughthe pipe string 1, and issues, as indicated by the arrows, from the mouth 32 at the lower end of the string.

During this operation no watr.,or any other substance is circulated in the jacket space 4, the valve 21 and other valves if necessary,

the jacket canJ be removed at any time:

After the well has been sunk to the desired depth, my apparatus may be utilized to cut o a water stratum by means of cement. In'

Fig. 3 I have illustrated the manner in which the apparatus accomplishes this purpose. Referring to this View, 35 represents a lwater stratum. In order to seal this stratum at the well 36, the jacket 2 is raised so that its lower end or mouth is disposed near the upper level of the stratum and I then'introduce the cement into the space 4 through the pipe connections 19 and 20 in the stuiiing box. This cement will gravitate down at the sides of the well and form an annular wall 37 surrounding the inner casing or string 1. In order to assist this movement ofthe cement, the water within the casing or string l is withdrawn by baling devices or by connecting the same with the suction side of the pump. .This will have the effect,

lnot only of drawing the-cement down at low the point of cementing. Before the cement sets the jacket is drawn up and kept ree by water circulation or rotation, as beore. According to some methods for sinking wells of this class an outer casingA is sunk without resorting to a water circulation on the outer side, and when this water circulation is omitted, this outer casing will t tightly in the earth bore, that is, it will `be frozen on its outer side in the earth. In the operation of sinking an inner casing within such an outer frozen casing my invention is applicable in order to free the inner casing, if earth adhesion orfrozen points should occur in the inner casingbelow the lower orifice of the outer casing. I have illustrated the manner in which the apparatus is used for this purpose in Fig. 4. Referring to this View, 38 indicates the frozen earth which is supposed to be at an intermediate point on the outer side of the inner `casing sooas to carry this earth downwardly to the lower orifice of the inner casing. This water will force the earth downwardly in jthis way and if it should eXert a tendency to lfrise around the outer side of the outer casing it will encounter a great resistance. The

earth and water should pass downwardly to the lower orifice of the ,inner casing, then passes into the interior ofthe inner 'casing f' and is raised in any suitable manner in the l interior of the inner caslng.

Having described vmy invention, what I claim as new and desire to secure by Letters Patent is:

l.' The process of drilling wells, which consists in sinkin an outer casino into the earth to a suitab e depth, then slnking an innercasing within said outer casing to a keep the sides of said casings free from earth adhesions thus permitting the withdrawal of the outer casing, owingcement down said annular space from above to seal off a water stratum at any point between the ground level and the lower orifice of vsaid inner casing and withdrawing said outerl casing before the cement sets. v

2. The process of drilling wells which consistsin sinking an outer casing into the earth toa suitable depth, then sinking an inner casing within said outer casing to a reater depth whereby an annular space is ormed between said innerl casing and said outer casing, circulating a fluid downwardly on the interior, and up the outer side of said outer casing to keep the side of said outer casing free from earth adhesions, owing cement down said annular space from above to shut off a water stratum at any point between the ground level andthe lower orifice of said inner casing, and withdrawing said outer casing before the cement sets.

-In witness that I claim the foregoing I have hereunto subscribed my name this 24th day of November, 1909.

'I v WILMER W. PEDDER.

Witnesses;

F. D. AMMEN, EDMUND A. STRAUSE.

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