Motor Integrated Reamer
In one aspect, an apparatus for use in a wellbore is disclosed that in one non-limiting embodiment may include a drive system coupled to a drill bit by a drive sub for drilling a wellbore, wherein the drive system has an associated bend for directional drilling of the wellbore, and a reamer driven by the drive sub, wherein the reamer reams a ledge formed at a transition from a larger diameter wellbore to a smaller diameter of the wellbore during directional drilling of the wellbore.
Latest BAKER HUGHES INCORPORATED Patents:
1. Field of the Disclosure
This disclosure relates generally to drilling assemblies for drilling directional wellbore.
2. Background of the Art
To obtain hydrocarbons, such as oil and gas, boreholes or wellbores are drilled by rotating a drill bit attached to a drill string end. A large proportion of the current drilling activity involves drilling deviated and horizontal wellbores (directional wellbores) for hydrocarbon production. Drilling systems include a drill string that has a drilling assembly (commonly referred to as bottomhole assembly or “BHA”) that includes a drill bit attached to an end thereof. The BHA includes a number of sensors, such as pressure, temperature, vibration and azimuthal sensors (commonly referred to a measurement-while-drilling (MWD) sensors) and tools for determining various properties of the earth formation (commonly referred to as logging-while-drilling “LWD” tool). BHA often includes a directional drilling device, which may be a bent sub or force application devices, such as ribs. For directional drilling, the BHA typically includes a motor, such as a positive displacement motor, driven by a drilling fluid (also referred to herein as the “mud motor” or “drilling motor”) to rotate the drill bit. Typically a bent sub is integrated in the motor. There are two operating modes for directional drilling with bent motors. The first is mode is the slide mode. In the slide mode, the drill string is not rotated. The motor drills a curved section (in-gauge hole). The bend generates a side force at the drill bit, deflecting the drill string. The second mode is the tangent mode. In the tangent mode, the drill string is rotated. The bend and the side force do not have a deflecting impact on the drill string. The motor drills straight ahead, but due to the bend, the hole is slightly oversized. If the next section is drilled in the slide mode, a ledge may be generated at the transition from the oversized hole to the in-gauge hole, which may cause a stabilizer commonly used on a bearing housing to hang up. This phenomenon has led to the use of slick motors, which however, provide less directional control.
The disclosure herein provides apparatus and methods that reduce or eliminates the ledge and, thus, the potential hanging of the bearing housing stabilizer.
SUMMARY OF THE DISCLOSUREIn one aspect, an apparatus for use in a wellbore is disclosed that in one non-limiting embodiment may include a motor coupled to a drill bit by a drive sub for drilling a wellbore, wherein the motor has an associated bend for directional drilling of the wellbore, and a reamer driven by the drive sub, wherein the reamer reams a ledge formed at a transition from a larger diameter wellbore to a smaller diameter of the wellbore during directional drilling of the wellbore.
In another aspect, a method of drilling a wellbore is disclosed that in one non-limiting embodiment may include: conveying a drilling assembly by a rotatable conveying member into a wellbore, the drilling assembly including a motor coupled to a drill bit, wherein the motor has an associated bend, a stabilizer, and a reamer downhole of the stabilizer; drilling the wellbore by rotating the drill bit by the rotatable conveying member and the motor to form a first section having a first size; and drilling the wellbore by rotating the drill bit by the motor only to form a second section of the wellbore, wherein transition from the first section to the second section includes a ledge; and utilizing the reamer to reduce the ledge to form the wellbore.
Examples of certain features of the apparatus and method disclosed herein are summarized rather broadly in order that the detailed description thereof that follows may be better understood. There are, of course, additional features of the apparatus and method disclosed hereinafter that will form the subject of the claims appended hereto.
The disclosure herein is best understood with reference to the accompanying figures in which like numerals have generally been assigned to like elements and in which:
In one aspect, the drill bit 150 is rotated by rotating the drill pipe 122. In another aspect, a drive system, such as downhole motor 160 (mud motor) disposed in the drilling assembly 190 is utilized to rotate the drill bit 150 alone or in addition to the drill string rotation. The drilling motor 160 includes a rotor that rotates a drive sub connected to the drill bit 150 (described later in reference to
In one aspect, a suitable drilling fluid 131 (also referred to as the “mud”) from a source 132 thereof, such as a mud pit, is circulated under pressure through the drill string 120 by a mud pump 134. The drilling fluid 131 passes from the mud pump 134 into the drill string 120 via a desurger 136 and a fluid line 138. The drilling fluid 131a from the drilling tubular 122 discharges at the borehole bottom 151 through openings in the drill bit 150. The returning drilling fluid 131b circulates uphole through the annular space or annulus 127 between the drill string 120 and the borehole 126 and returns to the mud pit 132 via a return line 135 and a screen 185 that removes the drill cuttings from the returning drilling fluid 131b. A sensor S1 in line 138 provides information about the flow rate of the fluid 131. Surface torque sensor S2 and a sensor S3 associated with the drill string 120 provide information about the torque and the rotational speed of the drill string 120. Rate of penetration of the drill string 120 may be determined from sensor S5, while the sensor S6 may provide the hook load of the drill string 120. Other sensors may be utilized to provide information about other parameters of interest.
Still referring to
Still referring to
Still referring to
Thus, in one aspect, a motor integrated reamer 185 is disclosed that in one non-limiting embodiment may be disposed on or integrated in a bearing assembly 329 below a stabilizer 182. The reamer 185 also herein is referred to as the motor integrated reamer. In one aspect, the reamer 185 is rotated by the power section 155 via a first gear wheel 310 on the drive sub 225, which rotates a second gear wheel 330 engaged to an inner teeth on the reamer 185. The second gear wheel 330 sits inside a housing 342, but has mud ports 350 integrated in the gear wheel housing 342 to allow passage of a coolant through the bearing assembly. The cutters 240 on the downhole side of the reamer 185 ream the ledge formed at the transition of the over-gauge wellbore (wellbore formed when the drill string is rotating) to the in-gauge wellbore (wellbore formed when the drill string is not rotating). Once the reamer 185 and the stabilizer 182 have passed the ledge, the contact to the borehole is on the stabilizer 182 and the reamer rotates idle, because the reamer outside diameter is less than the diameter of the stabilizer.
While the foregoing disclosure is directed to the certain non-limiting exemplary embodiments of the disclosure, various modifications will be apparent to those skilled in the art. It is intended that all variations within the scope and spirit of the appended claims be embraced by the foregoing disclosure.
Claims
1. An apparatus for use in a wellbore, comprising:
- a drive system coupled to a drill bit by a drive sub for drilling a wellbore, wherein the apparatus includes an associated bend for directional drilling of the wellbore; and
- a reamer driven by the drive sub, wherein the reamer reams a ledge formed at a transition from a larger diameter wellbore to a smaller diameter of the wellbore during directional drilling of the wellbore.
2. The apparatus of claim 1 further comprising a reamer drive coupled to the drive sub that rotates the reamer as the drive sub rotates.
3. The apparatus of claim 2 further comprising a bearing section on the drive sub and wherein the reamer drive is placed on the bearing section.
4. The apparatus of claim 2, wherein the reamer drive comprises:
- a first gear wheel coupled to the drive sub, wherein the first gear wheel rotates when the drive sub rotates; and
- a second gear wheel coupled to the first gear wheel and the reamer, wherein the second gear wheel rotates when the first gear wheel rotates to cause the reamer to rotate.
5. The apparatus of claim 4, wherein rotational speed of the reamer is defined at least in part by sizes of the first gear wheel and the second gear wheel.
6. The apparatus of claim 1 further comprising:
- a stabilizing device uphole of the reamer; and
- wherein outside diameter of the reamer is equal to or less than outside diameter of the stabilizing device and less than outside diameter of the drill bit.
7. The apparatus of claim 4, wherein the reamer drive contains seals separating the pressure level inside the bearing assembly from the pressure level inside the annulus between the reamer and the wellbore.
8. The apparatus of claim 4, wherein the second gear is in a sealed housing with a lubricant therein.
9. The apparatus of claim 1, wherein the drive system includes one of: a drilling motor and a turbine.
10. The apparatus of claim 4, wherein the second gear wheel is placed inside a housing that is sealed to the inside of the bearing assembly and includes at least one mud port to allow passage of a coolant through the bearing assembly.
11. The apparatus of claim 10 further comprising additional seals to generate an encapsulated cavity for the gear wheels to contain a lubricant to provide lubrication to the reamer drive.
12. A drilling system for directional drilling of a wellbore, comprising;
- a drilling assembly conveyable by a rotatable conveying member, wherein the drilling assembly includes:
- a drive system coupled to a drill bit by a drive sub for drilling a wellbore, wherein the drilling assembly has an associated bend for directional drilling of the wellbore; and
- a reamer driven by the drive sub, wherein the reamer reams a ledge formed at a transition from a larger diameter wellbore to a smaller diameter of the wellbore during directional drilling of the wellbore.
13. The drilling system of claim 12 further comprising a reamer drive coupled to the drive sub that rotates the reamer as the drive sub rotates.
14. The drilling system of claim 13, wherein the reamer drive comprises:
- a first gear wheel coupled to a drive sub, wherein the first gear wheel rotates when the drive shaft rotates; and
- a second gear wheel coupled to the first gear wheel and the reamer, wherein the second gear wheel rotates when the first gear wheel rotates to cause the reamer to rotate.
15. The drilling system of claim 12 further comprising a sensor for providing measurements relating to a property of interest during drilling of the wellbore.
16. The drilling system of claim 12, wherein the drive system includes one of a motor and a turbine.
17. A method of drilling a wellbore, the method comprising:
- conveying a drilling assembly by a rotatable conveying member into a wellbore, the drilling assembly including a drive system coupled to a drill bit, an associated bend, and a reamer downhole of the stabilizing device;
- drilling the wellbore by rotating the drill bit with the rotatable conveying member and the drive system to form a first section having a first size; and
- drilling the wellbore by rotating the drill bit by only the drive system to form a second section of the wellbore, wherein transition from the first section to the second section includes a ledge; and
- utilizing the reamer to reduce the ledge to form the wellbore.
18. The method of claim 17 further comprising determining one or more downhole parameters of interest during drilling of the wellbore and utilizing the determined one or more parameters of interest to form a deviated wellbore.
19. The method of claim 17, wherein the drilling assembly includes a stabilizing device and the outside diameter of the reamer is equal to or less than the outside diameter of the stabilizing device and less than the outside diameter of the drill bit.
20. The method of claim 17, wherein the reamer is driven by a reamer drive that includes:
- a first gear wheel coupled to the drive sub, wherein the first gear wheel rotates when the drive sub rotates; and
- a second gear wheel coupled to the first gear wheel and the reamer, wherein the second gear wheel rotates when the first gear wheel rotates to cause the reamer to rotate.
Type: Application
Filed: Nov 11, 2013
Publication Date: May 14, 2015
Applicant: BAKER HUGHES INCORPORATED (HOUSTON, TX)
Inventors: Thorsten Regener (Wienhausen), Jan Lukas Herlitzius (Hannover)
Application Number: 14/076,698
International Classification: E21B 4/00 (20060101); E21B 7/04 (20060101); E21B 7/00 (20060101); E21B 3/00 (20060101);