Patent ID: 12209459

DETAILED DESCRIPTION

FIG.1shows an oblique view of an example embodiment of a reaming tool10according to the present disclosure. The reaming tool10may comprise a reaming tool body12. The reaming tool body12may be made from any material known in the art to be used for connection within a drill string or assembly of drilling tools, including for example and without limitation, steel, monel, and an alloy sold under the trademark INCONEL, which is a registered trademark of Huntington Alloys Corporation, Huntington, W. Va. The reaming tool body12may comprise threaded connections (not shown) at its longitudinal ends to enable connection within a drill string or drilling tool assembly (not shown). The reaming tool body12may be assembled to such a drill string or drilling tool assembly (not shown) at a selected longitudinal position apart from (above when disposed in a well) a drill bit (not shown) to enable simultaneous drilling and reaming of a subsurface wellbore by rotating the drill string or drilling tool assembly and axially urging the drill string or drilling tool assembly to lengthen the wellbore and contemporaneously enlarge its diameter beyond that of the diameter drilled by the drill bit (not shown). In the present example embodiment, the direction of rotation of the reaming tool body12during such use is indicated by an arrow at11.

The reaming tool body12may comprise a plurality of reaming blocks14disposed about the circumference of the reaming tool body12. In the present example embodiment, there may be three such reaming blocks14(seeFIG.3), disposed at 120 degrees angular circumferential separation from each other. In other embodiments, more of fewer reaming blocks14may be provided while remaining within the scope of this disclosure. It is contemplated that a minimum of two reaming blocks14separated circumferentially by 180 degrees may be used in some embodiments. In other embodiments, the circumferential separation between reaming blocks14may be 360 degrees divided by the number or reaming blocks. In some embodiments, a circumferential surface dimension (distance about the circumference transverse to the longitudinal axis of the reaming tool body12) of each of the reaming blocks14may be inversely related to the number of reaming blocks.

The reaming blocks14may be made from, for example and without limitation, steel, monel or the INCONEL alloy set forth above. The reaming blocks14may have a wear resistant exterior layer such as may be made from metallic carbide, e.g., tungsten carbide or other wear resistant material. In the present example embodiment, gouging cutters18arranged in first rows20, and gouging cutters16arranged in second rows22may be affixed to at least one or each of the reaming blocks14. Each such first row20and second row22may be arranged to extend generally along the longitudinal dimension of the reaming tool body12; in some embodiments, one or each such first row20, and second row22of cutters may include some rotational (circumferential) offset or displacement with respect to position along the longitudinal dimension of the reaming tool body12, e.g., so as to traverse a helical pattern. In the present example embodiment, the second row22of gouging cutters16on any one or more reaming blocks may be disposed rotationally behind the first row20of gouging cutters18, “behind” meaning with reference to the direction of rotation11of the reaming tool body12during operation of the reaming tool10in a well.

In some embodiments, the first row20and the second22row of cutters18,16may be separated by a junk slot24or similar structure formed in the face of the reaming block14to provide a path to enable reaming tool cuttings to be readily moved away from the reaming block14during reaming operations. The reaming tool cuttings may be moved by the flow of drilling fluid or other wellbore fluid circulated through the drill string during drilling and/or reaming operations and consequently lifted out of the well (not shown) to the surface.

As stated above, in the present example embodiment, the first row20of gouging cutters18may be located rotationally ahead of the second row22on any one or more reaming blocks14. Thus, the gouging cutters18in the first row20contact and thus cut (ream) the formation before the gouging cutters16in the second row22. The gouging cutters18in the first row20may each be disposed directly rotationally in front of a corresponding gouging cutter16in the second row22, or, as shown inFIG.1, may be longitudinally alternated with the cutters16in the second row22. Longitudinally alternating means that at any longitudinal position, substantially only one first row cutter or one second row cutter is present, it being within the scope of such definition that some longitudinal overlap may exist between first row cutter and second row cutters depending on the longitudinal spacing between adjacent cutters in any individual row and the diameter of the cutters.

The reaming blocks14may define a cutting profile surface28such that the diameter subtended by the gouging cutters18,16increases with respect to longitudinal position along the direction of reaming of the reaming tool10, that is, the subtended diameter increases with increasing distance away from the drill bit (not shown) coupled ahead of the reaming tool10.

The profile surface28may be better observed inFIG.2. Any profile surface known to be used for fixed cutter reaming blocks may be used in various embodiments; some such embodiments will be further explained below with reference toFIGS.3and4. The reaming blocks14may each define a gage surface26proximate a longitudinal upper end (farthest away from the drill bit) of the reaming block14. The gage surface26may serve to stabilize motion of the reaming tool10in a wellbore to produce a relatively smooth wellbore interior surface as a result of reaming. At an upper end of one or more of the reaming blocks14, a backreaming cutter assembly21may be provided above the upper longitudinal end of the gage surface26. The backreaming cutter assembly21may comprise at least gouging cutters30arranged rotationally and longitudinally as in the rows20,22of gouging cutters in the profile28part of the reaming block14.

The gouging cutters18,16may be configured to be mounted directly to the reaming block14in corresponding pockets (not shown separately) such as by brazing. The gouging cutters in some embodiments may be mounted to the reaming block14so as to be rotatable within the respective mounting pocket, e.g., using snap rings or similar retaining devices. The gouging cutters18,16in some embodiments may be mounted so that the respective longitudinal axis (CL inFIG.4) of each of the gouging cutters is within 30 degrees of perpendicular to the face (F inFIG.3) of the respective reaming block14. In the embodiment shown inFIG.1, the mounting and arrangement of the gouging cutters18,16may enable increased cutting coverage, that is, having cutters disposed at more diameter positions between the gage diameter of the drill bit (not shown) and the gage diameter, defined by the gage surface26, of the reaming tool10than would be possible using other mounting and arrangement of gouging cutters18,16on any or each reaming block14. The gouging cutters18,16are mounted to the reaming blocks14so that the respective position with reference to the reaming tool body12is fixed, that is, the gouging cutter longitudinal position does not change during reaming operation. Such mounting is thus distinguishable from mounting of cutters on a roller reaming tool, wherein cutters mounted on one or more rollers move position with reference to the tool body during operation. The foregoing explanation, made in terms of reaming operation of a roller reaming tool, is intended to exclude reaming tools which have reaming blocks movably mounted to the reaming tool body, in which the cutters may move laterally with the reaming blocks but not longitudinally other than incidental longitudinal motion in some types of radial expansion mechanisms.

The gouging cutters18may be substantially ballistically shaped, i.e., conically shaped or dome (hemispherically) shaped. In any event, the shape of the gouging cutters18,16may be such that the cutting surface is non-planar, as contrasted with shear cutters known in the art which have essentially planar cutting surfaces. The gouging cutters18,16may be made from steel covered with a wear resistant material such as metal carbide. Such carbide may be, e.g., tungsten carbide, or the gouging cutters18,16may be made entirely from metal carbide, e.g., tungsten carbide. In some embodiments, some or all of the gouging cutters18,16may be made from or may be covered by a layer of “ultra hard” material such as polycrystalline diamond (PCD) or cubic boron nitride (CBN). In some embodiments, some or all of the gouging cutters18,16may be made in the form of a diamond monolith. In some embodiments, some or all of the gouging cutters18,16may comprise impregnated diamond in the body of the gouging cutter(s)18,16, which may be made from a different material such as tungsten carbide.

FIG.2shows a side view of an example embodiment of the reaming tool10, wherein a view of some of the possible features of the reaming blocks14are more clearly observable. A possible cutting profile28may be readily observed in the side view of the reaming block14in the upper part ofFIG.2, as well as a profile subtended by a backreaming cutter assembly21located above the top of the gage surface26. “Above” in the present context means in a direction toward the surface end of a subterranean well in which the reaming tool10may be deployed. One example of a shape of the junk slot24may be observed in the lower reaming block14shown inFIG.2. The relative rotational and longitudinal positions of the gouging cutters18in the first row20and the gouging cutters16in the second row22that may be present in some embodiments may be better observed in the lower part ofFIG.2. In the embodiment shown inFIG.2, the first row20and the second row22may both be on the same side of the junk slot24. In embodiments such as inFIG.2, a further first row20and second row22may be located on the opposite side of the junk slot24. The longitudinal positions of the gouging cutters18in the first row20may be longitudinally staggered with respect to the longitudinal positions of the gouging cutters16in the second row22. Such longitudinal arrangement of the gouging cutters18,16may enable more diameter coverage of the reaming tool10.

For purposes of defining the scope of the present disclosure, it is only necessary that at least one reaming block14to have more than one row of cutters, wherein a “row” is defined as longitudinally substantially contiguously arranged gouging cutters along the longitudinal dimension of the reaming block14, for the first row20of gouging cutters18to be disposed rotationally ahead of the second row22of gouging cutters16on the same reaming block14. Rotationally ahead may be defined as forward along the direction of rotation11.

FIG.3shows a cross section of the reaming tool10along line3-3′ inFIG.1. The gage surface26of each reaming block14is arranged to be disposed at a selected radius R from the center or rotation C of the reaming tool body12. A radius of curvature RC of each gage surface26may be selected to match the selected radius R defined by each gage surface26. The present example embodiment comprises three reaming blocks14. As explained above with reference toFIG.1, more or fewer reaming blocks14may be used in other embodiments to equal effect. The direction of rotation is indicated inFIG.2at11. The surface F of the reaming blocks may be observed in order to better understand mounting of the gouging cutters18,16.

FIG.3also shows various possible embodiments of arrangements of gouging cutters18,16on each reaming block14. The uppermost reaming block14inFIG.3may comprise four rows of gouging cutters, arranged in two, first rows20wherein each such first row20is rotationally ahead of a corresponding second row22. One first row20and one second row22may be disposed on the rotationally leading side of the junk slot24. The other first row20and second row22may be disposed on the rotationally trailing side of the junk slot24. On either or both of the other reaming blocks14, only one first row20and one second row22of cutters may be disposed, each on opposed sides of the respective junk slot24as shown. The first rows20and second rows22may be arranged longitudinally so that the cutters18,16in each row20,22longitudinally alternate, as explained with reference toFIGS.1and2. Such arrangement may provide increased diametric reaming coverage between the gage diameter of the drill bit (not shown) and the gage diameter of the reaming tool. As explained previously, it is only necessary to have a first row20and a second row22of gouging cutters on at least one reaming block14; presence of absence of cutters and their arrangement on any of the other reaming blocks is a matter of discretion.

FIG.4shows another possible arrangement of the gouging cutters that may be used in some embodiments. The view inFIG.4is known as a profile view, wherein a cross-section of the reaming tool is rotated into a single plane to better observe the cutting pattern defined by the gouging cutters16,18. The gouging cutters18in the first row or first rows (e.g.,20inFIG.1orFIG.3) may define a first profile P1. The gouging cutters16in the second or rows (e.g.,22inFIG.1orFIG.3) may define a second profile P2. The first and second profiles P1, P2may each be understood as a curve that connects the outermost point on each cutter in each profile. In the example embodiment inFIG.4, the first profile P1may define a curve in which for any longitudinal position along the reaming block (14inFIG.2), a cutter located on the first profile P1defines a larger cutting diameter than a cutter located in the same corresponding longitudinal position on the reaming block on the second profile P2. As may be understood with reference toFIG.2in particular, and along the direction of arrow A along the centerline CL inFIG.4, cutters located at corresponding longitudinal positions, meaning a same distance from one longitudinal end of the reaming tool along each reaming block (14inFIG.2) define essentially the same (reaming) diameter at any circumferential position around any reaming block (14inFIG.1). In some embodiments, a diameter offset of the first profile P1with reference to the second profile P2may be constant. In some embodiments, and as shown inFIG.4, a diameter offset of the first profile P1with respect to the second profile P2may vary with respect to distance from the center of rotation (C inFIG.3) of the reaming tool. The example embodiment shown inFIG.1has a first offset X at diametric distance D1that is larger than a second offset Y at diametric distance D2. The offset in the example embodiment ofFIG.4decreases monotonically to zero at the gage diameter of the reaming tool. In other embodiments, a variable offset may change in any other way between largest and smallest offsets with respect to diameter.

A reaming tool according to the present disclosure may provide increase reaming performance and have increased longevity over reaming tools known in the art prior to the present disclosure.

Although only a few examples have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the examples. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.