US1269090A - Method for cementing wells. - Google Patents

Description

S. L. KISTLERI'. Y

METHOD Foa clan/:Emme wELLs.

APPLICATION FILED APR.20. i917.

Patented June 11, 1918.

SAMUEL L. KISTLER, OF LOS ANGELES, CALIFORNIA.

METHOD FOR CEMENTING WELLS.

l Substitute for application'iiled November 15, 1915,. Serial No. 61,691. e April 20, 1917. Serial No. 163,528.

To all whom t may concern.'

Be it known that I, SAMUEL L. Kleiman,

a citizen of the United States, residing at Los Angeles, in the-county of Los Angeles and State of California, have invented a new V and useful Method for Cementing Wells, of which the following is a specification.

voil wells with a metal casing,

the fact that this water finds its way into the loil bearing strata and into the various wells which are drilled therein. Any means by which the security of the oil well against the loss of the hole, and increase of water, can be secured, is therefore of great importance in the art.

To provide this security is the present practice to use cement, this cement being forced through the casing and up around the exterior thereof, hardening in place so as to shut off the flow of the water bycementing the casing lto the rock structure through which it passes.

The principal obj ectof my invention is to guarantee the alinement of thecasing during the cementing of the well.

The method and apparatus is well illustrated vin the drawing, in which Figures 1, 2, 3 and 4 represent successive stages in thedrawing, the actual conditions in these stages being more fully set forth in the following description.

In these drawings, 11 represents an .oil well casing of indefinite length, this casing extending downwardly through the bore of. the well, being supported by a suitable.

means at the upper end. 12 represents a shell, as it is commonly called, of hard rock through which the casing passes, this shell having a formation of soft material 13 above, and a formation 14 of similar material below. The formationsl'and 1.4 may be loose sand, rock, or the l1ke. It 1s supspecication. of Letters Patent.

Patented J une 11, 1918.

posed that the formation 13 contains water, or that formations directly above it contain Water, so thatA there is a seepage of' water downwardly, (of course water can come from below upwardly, as is obvious, undery reverse conditions, if a hol'e should be drilled through sired to be saved), around the casing 1l, and through the opening in the shell 1'2, this water passing'downwardly into the formal tion 14, and through the formation 14 into the oil bearing sands or into the interior-0f the well itself. The operator of the well wishes to introduce cement between th shell 12 and the casing 11 in such a quantity and .1n such a manner that an absolutely watertlght joint will be formed between the casing 11 and the shell 12, the shell 12 being supposed to be ofsuch a nature that water will not readily pass therethrough. The lower portion of the casing 11 may be of Very considerable length, and`it would be Divided and this application led a water stratum below the point deimpractical to force the cement downwardly through the casing, and upwardly between the formation 14 and the casing into the space around the shell 12. It is therefore necessary to provide a cut 15 in the casing which is then raised, a bridge 16 being first secured approximately in the location shown in the drawings. This bridge is formed in a variety of ways by the introduction of plugs of various kinds in the casing, and in some cases by the introduction of vcement which hardens and completely closes the casing. By cutting the casing at the point 15 Vand raising it, it would be possible to force cement into the formations-.13 and 14, and

in and aroun the shell 12. As the formations .13 and 14 are supposed to be loose ones, and as the casing 11 may have considerablestresses due to a crooked hole or the like, it is very likely that when the casingI is again dropped down that the upper portion 17 and the lower portion 18, which were divided by the cut 15, might not meet exactly, or indeed it is possible thatv the upper portion 17 would be sui'liciently displaced by the side of the portion 18 so that the lower portion of the hole, or well, would be lost.` To prevent this diiliculty I provide a guide section 20. This guide 20 is provided with perforations 23. perforations are shown in the form of slots While these in the drawing, they may be round, square or location, so long or of any desired shape,

' which will now as they serve their purpose be explained.

The method of drilling the well, using the guide 20, is as follows:

The portion 16 being placed at a deslrable point in the casingll, and being secured therein with water-tight relation with the casing, the groove'l is cut in the wall of the casing, this groove however, not entirel separati'n the casing into two sections 1 and 18. `he well at this time is in the condition shown in Fig. 1. The guide 20 is then placed in position, the parts being in the relation shown in Fig. 2. The .operator then lifts, or twists, the upper section 17 of the casing, breaking the casing at the groove inside the casing 17, passing through the guide perforations 23 in'to the channels of least resistance leading from the perforated guide 20. When the upper section 17 has been lifted it is generally found desirable to circulate Water through the casing and up- -wardly around the upper portion thereof.

This lcirculation of water will commonly form a pocket 30, above the formation so` that a relatively large opening is left on the upper side of the shell 12. This space, as well as the interior of the guide 20, and a portion of the casing, is Afilled with cement. This cement may also surround the. opening in the shell 12, on either side yof the shell, and extending up and down inside the well for a considerable distance, (on either side of the shell), passing into and unitin in ,some degree with the formations 13 an 14.

Before this cement has an opportunity to set, thel upper section 17 of the casingis ed back into lts original position, and

dropp it is here that the great utility of the guide 20 is shown, as this guide positively Ainsures that the sections 17 and 18 will meet in exact alinement. While the joint formed between the casings 17 and 18 is not absolutely watertight in itself, the presence of the lcement recepeninside and outside the joint insures a practical water-tight joint as soon as this cement has an opportunit to set. The mass of cement in the cavities 30 and 31, and in -the space between the formation 12 and sections 17 and 18 of the casing 11, is then allowed to set. Drilling tools are then put into the well and the cement which is hardened inside the casing 11 and guide 20 is drilled out, the bridge 16 also being drilled out so that the bore of the well is again open and drillin operations may be resumed as indicate Themass of cement in the cavities 30 and 31 adhering tightly to the casing 11, effectually holds the casing in alinement even if the guide 20 is removed. In many cases it is possible to pull the 'de 20 from the hole by jarrin the cement is weaened.

I claim as my invention 1. The method of cementing wells which consists in placing a water-tight bridge in the casing below the point to be cemented, partially separating the casing near the point to be cemented, placing a guide in the casin on said bridge, said guide being of suficlent length to extend past the place at which the partial separation has been made, exerting force on said casing to cause it to separate, lifting the casing to enlarge the separation, pumping cement into the casing, lowering the casing to close 'the separation, allowing the cement to set, and clearing the interior of Ithe casing of obstructions.

2. The method of cementing between an oil well casing and an impervious shell which consists in separating the casing near the shell, pumping cement into the space around the shell through the separation in thecasing, lowering the casing to close the separation, and allowing the cement to set, the sections of casing on either side of the separation being held in alinement by a suitable guide.

3. The method of insuring the realinementl of casing separated in cementing an oil well which consists in supporting inside the casing during the cementing operations an' internal gui e of suliicient length to bridge the separation.

. lin testimony whereof, ll have hereur'ito yset my hand at Los Angeles, California, this 29th day of March, 1917.

SAMUEL L. KTSTLER.

it so that t e bond with

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