Boring or penetrating the earth – Automatic control – Of fluid pressure below ground
Reexamination Certificate
1999-01-07
2001-09-18
Will, Thomas B. (Department: 3671)
Boring or penetrating the earth
Automatic control
Of fluid pressure below ground
C175S107000
Reexamination Certificate
active
06289998
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to drilling wellbores and more particularly to a drilling system utilizing a downhole pressure intensifier for jet-assisted drilling.
2. Background of the Art
To obtain hydrocarbons such as oil and gas, boreholes are drilled by rotating a drill bit attached to a drill string. A large proportion of the current drilling activity involves directional drilling, i.e., drilling deviated and horizontal boreholes, to increase the hydrocarbon production and/or to withdraw additional hydrocarbons from the earth's formations.
Modern directional drilling systems generally employ a drill string having a drill bit at the bottom that is rotated by a drill motor (commonly referred to as the “mud motor”). A plurality of downhole devices are placed in close proximity to the drill bit to measure certain downhole operating parameters associated with the drill string and to navigate the drill bit along a desired drill path.
Positive displacement motors are commonly used as mud motors. U.S. Pat. No. 5,135,059, assigned to the assignee hereof and which is incorporated herein by reference, discloses a downhole drill motor that includes a power section having a housing, a stator having a helically-lobed inner elastomeric surface secured within the housing and a rotor having a helically-lobed exterior metallic surface disposed within the stator. Pressurized drilling fluid (commonly known as the “mud” or “drilling mud”) is pumped into a progressive cavity formed between the rotor and stator. The force of the pressurized fluid pumped into the cavity causes the rotor to turn in a planetary-type motion. A suitable shaft connected to the rotor via a flexible coupling compensates for eccentric movement of the rotor. The shaft is coupled to a bearing assembly having a drive shaft (commonly referred as the “drive sub”) which in turn rotates the drill bit attached thereto. Radial and axial bearings in the bearing assembly provide support to the radial and axial movements of the drill bit. For convenience, the power section and bearing assembly are collectively referred to herein as the “motor assembly.” Other examples of the drill motors are disclosed in U.S. Pat. Nos. 4,729,675, 4,982,801 and 5,074,681, the disclosures of which are incorporated herein by reference.
For drilling in rock, the assistance of a jet of high pressure fluid facilitates the drilling operation. Some of the current operations supply the high pressure directly from the surface by either generating the high pressure for the entire fluid flow or operating a smaller amount of high pressure fluid via additional conduits inside the drill pipe. These prior art high pressure systems utilize high pressure pumps or pressure intensifiers at the surface. These systems are relatively expensive and unreliable and thus have not gained commercial acceptance.
The present invention addresses the above-described problems with the prior art methods for jet-assisted drilling and provides novel apparatus and methods for generating high pressure fluid flow downhole.
SUMMARY OF THE INVENTION
The present invention provides apparatus and methods for generating high pressure fluid jet downhole during drilling of the boreholes. The high pressure jet is discharged at the drill bit bottom to aid drilling of the boreholes. A preferred embodiment of the system includes a pressure intensifier disposed between a drilling motor and the drill bit. The drilling motor produces a rotary force as the drilling fluid passes through the drilling motor. The pressure intensifier includes a rotatable sleeve having at least one port for admitting drilling fluid. The rotary force of the drilling motor rotates the rotating sleeve causing the drilling fluid to enter a chamber. A reciprocating differential piston in the rotating sleeve discharges the fluid from the chamber at a high pressure to the drill bit bottom. The preferred embodiment utilizes a dual acting piston that reciprocates between two chambers. During each rotation of the rotating sleeve, the piston discharges at high pressure the fluid from each such chamber.
The pressure intensifier generates pulses of a defined frequency, which act as a carrier of signals and data transmitted uphole (to the surface). A pulse frequency control device or valve coupled to the drilling motor acts as the frequency modulator. A controller or processor in the downhole assembly operates the pulse control frequency device at at least two (at two or more) frequencies, each such frequency representing a binary bit of a digital signal.
Examples of the more important features of the invention have been summarized rather broadly in order that the detailed description thereof that follows may be better understood, and in order that the contributions to the art may be appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject of the claims appended hereto.
REFERENCES:
patent: 3112800 (1963-12-01), Bobo
patent: 3897836 (1975-08-01), Hall et al.
patent: 3927723 (1975-12-01), Hall et al.
patent: 4047581 (1977-09-01), Erickson
patent: 4462469 (1984-07-01), Brown
patent: 4534427 (1985-08-01), Wang et al.
patent: 4729675 (1988-03-01), Trzeciak et al.
patent: 4819745 (1989-04-01), Walter
patent: 4936397 (1990-06-01), McDonald et al.
patent: 4982801 (1991-01-01), Zitka et al.
patent: 5073877 (1991-12-01), Jeter
patent: 5074681 (1991-12-01), Turner et al.
patent: 5079750 (1992-01-01), Scherbatskoy
patent: 5135059 (1992-08-01), Turner et al.
patent: 5246080 (1993-09-01), Horvei et al.
patent: 5361857 (1994-11-01), Horvei
patent: 5375671 (1994-12-01), Horvei
patent: 5455804 (1995-10-01), Holmes et al.
patent: 5632604 (1997-05-01), Poothodiyil
patent: 5817937 (1998-10-01), Beshoory et al.
patent: 5890547 (1999-04-01), Nilsen
patent: 6016288 (2000-01-01), Frith
patent: 0.661.459.A1 (1995-07-01), None
patent: 2.281.424 (1995-03-01), None
patent: WO 97/06336 (1996-08-01), None
patent: WO 96/30618 (1996-10-01), None
patent: WO 96/30619 (1996-10-01), None
Krueger Volker
Kruspe Thomas
Baker Hughes Incorporated
Madan Mossman & Sriram P.C.
Petravick Meredith C
Will Thomas B.
LandOfFree
Downhole tool including pressure intensifier for drilling... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Downhole tool including pressure intensifier for drilling..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Downhole tool including pressure intensifier for drilling... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2438490