Boring or penetrating the earth – Bit or bit element – Rolling cutter bit or rolling cutter bit element
Reexamination Certificate
2001-04-16
2003-06-24
Will, Thomas B. (Department: 3672)
Boring or penetrating the earth
Bit or bit element
Rolling cutter bit or rolling cutter bit element
C175S339000, C175S393000
Reexamination Certificate
active
06581702
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to the field of oil field drilling equipment. More specifically, the invention relates to a three-cone rock bit using a non-plugging center jet nozzle with a plurality of side passageways that are situated in a staggered fashion to prevent balling, or packing of the drill bit.
2. Related Art
In the drilling of oil wells, drilling fluid, or mud, provides lubrication, cooling, and cleaning by high pressure jets for the drill bit and provides for removal of the cuttings from the well bore. The mud circulates down through a drill string, into the drill bit body, typically through three nozzles positioned within the drill bit, and toward the bottom of the well bore. Nozzles are particularly useful because the relatively high-pressure mud creates high velocity jet streams within the hole and stir up formation cuttings, thus facilitating their circulation and removal from the well bore. From the well bore bottom, the mud circulates back to the surface carrying formation cuttings from the well bore. The process of removing the cuttings away from the bit and the efficiency with which it is accomplished is an important factor in determining the rate of penetration of the drill bit and, thus, the efficiency of the drilling. Therefore, increasing the efficiency of the removal of the cuttings increases the drilling efficiency.
Typically, drill bits define a void between and above cutter cones. Drilling mud and formation cuttings often accumulate within the void between and above cutting surfaces, thereby forming a mud ball that becomes impacted. This process, or phenomenon, of accumulation and impacting is generally referred to as “balling” or “packing off.” Balling reduces the efficiency of the drilling process because a portion of the bit known as the dome (area above cutter cones) is packed off, causing the rotary cutter cones to become locked. This causes rotary cutter cones to skid on the bottom of the hole, therefore, slowing the rate of penetration. Thus, the drill bit and components should be designed to avoid balling.
The past benchmark for curtailing bit balling has been the installation of a fourth jet in the center of the bit (dome area). In the prior art, a single stream of drilling mud passing through the dome area of the bit provided some relief toward eroding a bit ball. However, additional improvements are needed in this area to reduce bit balling and thus improve efficiency per foot drilled. A multi-ported jet nozzle is needed to clean a larger area of dome and to reach those portions of bit domes inaccessible to the stream of a single port nozzle. Prior to the present invention, a design dilemma existed with respect to center-jet nozzles attempting a plurality of sideports (with more than one jetting stream). Namely, in a drill bit typically employing three nozzles and a fourth center jet nozzle, flow to the center jet nozzle is limited by virtue of flow to other nozzles. Therefore, multi-ported nozzle holes on a center jet are necessarily smaller so as not to unduly diminish drilling mud flow to other non-center jet nozzles. The design dilemma with such smaller holes in multi-ported center jet nozzles is that they cannot be run in a normal drilling operation because of the risk of their becoming plugged with impediments typically present in drilling mud. When plugging of these smaller holes in the central nozzle occurs, the usefulness of the center jet is compromised. The present invention solves this problem, thus enabling the use of small orifices to be run in a multi-ported nozzle without becoming plugged.
SUMMARY OF THE INVENTION
Accordingly, the objectives of the present invention are to provide an improved drill bit that:
provides greater drilling efficiency than previous drill bits;
provides greater cleaning for drill bit cutting surfaces;
provides a reduction of balling within the dome of rotary drill bits;
provides a reduction of mud and debris accumulation in the drill bit void and on cutting surfaces;
eliminates clogging of drill bit nozzles;
utilizes a nozzle with a plurality of side passageways (multi-ported);
provides an internal nozzle cavity (central passageway) shape that facilitates a constant drilling mud (fluid) velocity within the nozzle and that prevents clogging of side passageways by particles in the drilling mud;
utilizes descending tapered shapes within the nozzle to maintain velocity of drilling mud as drilling mud is injected through the nozzle, thereby preventing clogging of side passageways by particles in the drilling mud;
utilizes side passageways in the nozzle strategically situated at staggered heights on the nozzle body, and situated at varying angles, upward and downward to maximize cleaning, minimize balling, and increasing drilling efficiency;
utilizes a main exit aperture on the multi-ported nozzle of sufficient size to avoid plugging, thereby ensuring that the side passageways will remain unobstructed;
utilizes a central position of the nozzle within the drill bit;
and that uses a range of drilling mud injection velocities into the nozzle, so that clogging is reduced within the nozzle and so that the nozzle best sustains wear from injection of drilling mud, and particularly for preventing damage within the nozzle at the point where the central passageway meets the inlet orifices to the side passageways.
To achieve such improvements, the present invention generally provides a three cone rock bit, incorporating a non-plugging center jet nozzle fixed along a vertical central axis of the drill bit body and above the cutter cones. In general, the nozzle has a main inlet aperture, a main exit aperture, and a central passageway extending between the inlet and exit apertures. Side passageways intersect the central passageway and provide a bore through the nozzle sidewall through which drilling mud exits. Typically, inlet orifices to the side passageways are staggered vertically at different heights along the nozzle sidewall defined by the descending central passageway. Each of the side passageways also has an exit orifice occurring at an exterior surface of the nozzle.
The nozzle of the present invention includes a top, a bottom, a central passageway, sidewall, and central vertical axis. A central passageway extends from the top to the bottom of the nozzle in an axial direction so that the cavity formed by the central passageway also defines a sidewall of the nozzle that preferably varies in thickness depending on the width of the central passageway. The central passageway defines an inlet aperture at the top of the nozzle, and a main exit aperture at the bottom of the nozzle. The nozzle also defines a plurality of side passageways extending through the sidewall intermediate the top and bottom of the body and with the side passageways in fluid communication with and intersecting the central passageway which has conical or other tapering shape descending to the main exit aperture.
In the preferred embodiment, a non-plugging nozzle is centrally positioned along a vertical central axis within a rotary drill bit. The drill bit has a first end comprised of a bit body adapted for connection to a drill string and a second end of the bit delimiting a cutting surface formed by a plurality of rotary cutter cones. The drill bit defines at least one void formed between and the rotary cutting devices (cutter cones). The nozzle of the present invention extends into the void, or drill dome, above the cutter cones. This center nozzle includes means for functionally connecting to and remaining in fluid communication with the drill string. The nozzle directs drilling mud from the drill string through the bit and toward target voids and cutter cones. The rotary cone drill bit has a connecting means, or pin, at the upper end of the drill bit body that connects the rotary cone rock bit to a drill string. Preferably, the connecting means, or pin,
Dickey Winton B.
Hudson III James E.
Keeling Kenneth A.
Petravick Meredith
LandOfFree
Three-cone rock bit with multi-ported non-plugging center... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Three-cone rock bit with multi-ported non-plugging center..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Three-cone rock bit with multi-ported non-plugging center... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3107988