System for directional drilling and related method of use

• US 4,854,397 A
• Filed: 09/15/1988
• Issued: 08/08/1989
• Est. Priority Date: 09/15/1988
• Status: Expired due to Fees

• Current Assignee: Amoco Corporation (BP PLC)
• Original Assignee: Amoco Corporation (BP PLC)
• Inventors: Warren, Tommy M., Winters, Warren J.
• Primary Examiner(s): NOVOSAD, STEPHEN
• Application Number:
  US07/244,770
• Time in Patent Office: 327 Days
• Field of Search: 175/24, 175/26, 175/27, 175/45, 175/40, 73/151, 364/420
• US Class Current: 175/26
• CPC Class Codes: E21B 4/20 combined with surface drive E21B4/10 takes precedence
• CPC Class Codes: E21B 44/00 Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions
• CPC Class Codes: E21B 44/005 Below-ground automatic control systems
• CPC Class Codes: E21B 47/022 of the borehole, e.g. using geomagnetism
• CPC Class Codes: E21B 7/068 drilled by a down-hole drilling motor down-hole drives per se E21B4/00, E21B7/067 takes precedence

Abstract

A system for directional drilling and related method of use is described herein which utilizes a drillstring suspended within a wellbore with an MWD and downhole turbine or motor connected adjacent a drill bit on a lower end of the drillstring, and with a top drive and/or rotary table connected adjacent an upper end of the drillstring. Within the method, desired limits of drilling associated parameters are inputted into a memory associated with a programmable digital computer. While drilling the wellbore, transmitted values of the drilling associated parameters are inputted into the memory. If the transmitted values are outsude of the desired limits, necessary adjustments are calculated and then made to weight-on-bit (WOB), RPM and/or drillstring azimuthal orientation to bring the transmitted values within the desired limits.

Claims

1. A method of controlling the path of a drillstring during directional drilling operations that utilizes downhole data collection and transmission means and drill bit rotation means connected adjacent a drill bit on a lower end of the drillstring, and with drillstring rotation means connected adjacent an upper end of the drillstring, the method comprises:

(a) inputting permitted limits of variance from a preselected drillstring azimuthal direction into memory means associated with a programmable digital computer;

(b) controlling the drillstring rotation means to maintain a fixed desired drillstring azimuthal orientation, and while drilling the wellbore utilizing the drill bit rotation means, transmitting a value of the downhole drillstring azimuthal direction to memory means associated with the programmable digital computer;

(c) if the transmitted value of step (b) is outside of the permitted limits, calculating within the programmable digital computer the required direction and degrees of rotation of the drillstring required to bring the transmitted value within the permitted limits; and

(d) utilizing the programmable digital computer to momentarily activate the drillstring rotation means to incrementally rotate the drillstring in accordance with step (c).

2. An automatic directional drilling system for use in drilling operations that utilizes downhole data collection and transmission means and drill bit rotation means connected adjacent a drill bit on a lower end of the drillstring, and with drillstring rotation means connected adjacent an upper end of the drillstring, the system comprises:

means associated with a programmable digital computer for storing permitted limits of variance from a selected drillstring azimuthal direction and comparing received value of the downhole drillstring azimuthal direction;

means associated with the programmable digital computer for calculating any required quantity and direction of rotation of the drillstring required to bring the received value within the desired limits; and

means associated with the programmable digital computer for controlling the drillstring rotation means to effectuate the calculated quantity and direction of rotation of the drillstring.

3. An automatic directional drilling system for use in drilling operations utilizing a downhole data collection and transmission means and drill bit rotation means connected adjacent a drill bit on a lower end of a drillstring, and with hydraulic drillstring rotation means connected adjacent the upper end of the drillstring, the system comprises:

means associated with a programmable digital computer for storing permitted limits of variance from a selected drillstring azimuthal direction and comparing received values of the downhole drillstring azimuthal direction;

means associated with the programmable digital computer for calculating any required direction and degrees of rotation of the drillstring required to bring the received values within the permitted limits; and

means associated with the programmable digital computer for controlling hydraulic servocontrol valve means associated with the drillstring rotation means to effectuate the calculated direction and incremental degrees of rotation of the drillstring.

4. A directional drilling system for use in drilling a wellbore having a desired inclination and azimuthal direction and utilizing a drillstring suspended within a wellbore with downhole data collection and transmission means and drill bit rotation means connected adjacent a drill bit on the lower end of the drillstring, and with hydraulic drillstring rotation means connected adjacent an upper end of the drillstring, the system comprises:

means associated with a programmable digital computer for storing a desired inclination and final azimuthal direction of the wellbore, physical characteristics of the drillstring, and transmitted values of drilling associated parameters;

means associated with the programmable digital computer for calculating desired changes to weight-on-bit (WOB), RPM and/or drillstring azimuthal orientation necessary for the wellbore to achieve the desired inclination and final azimuthal direction; and

means associated with the programmable digital computer for controlling hydraulic servocontrol valve means associated with the drillstring rotation means for incrementally adjusting the drillstring azimuthal orientation and/or drill bit rotation means to effectuate the calculated drilling changes.