Drilling systems with sensors for determining properties of drilling fluid downhole

• US 6,176,323 B1
• Filed: 06/26/1998
• Issued: 01/23/2001
• Est. Priority Date: 06/27/1997
• Status: Expired due to Term

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Weirich, John B., Smith, William W. Jr., Nasr, Hatem N., Krueger, Volker, Bland, Ronald G., Harrell, John W., Papanyan, Valeri
• Primary Examiner(s): PEZZUTO, ROBERT ERIC
• Application Number:
  US09/111,368
• Time in Patent Office: 942 Days
• Field of Search: 175/39, 175/40, 175/41, 175/42, 175/50, 175/45, 175/46, 175/44, 166/250, 731/520.3, 731/520.1, 731/525.2, 731/51, 731/52
• US Class Current: 175/40
• CPC Class Codes: E21B 21/08 Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure valve arrangements therefor E21B21/10
• 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 47/00 Survey of boreholes or wells monitoring pressure or flow of drilling fluid E21B21/08
• CPC Class Codes: E21B 47/002 by visual inspection
• CPC Class Codes: E21B 47/06 Measuring temperature or pressure
• CPC Class Codes: E21B 47/07 Temperature
• CPC Class Codes: E21B 47/085 using radiant means, e.g. acoustic, radioactive or electromagnetic
• CPC Class Codes: E21B 47/11 using tracers; using radioactivity
• CPC Class Codes: E21B 47/113 using electrical indications; using light radiations
• CPC Class Codes: E21B 47/114 using light radiation
• CPC Class Codes: E21B 49/005 Testing the nature of borehole walls or the formation by using drilling mud or cutting data

Abstract

The present invention provides a drilling system for drilling oilfield boreholes or wellbores utilizing a drill string having a drilling assembly conveyed downhole by a tubing (usually a drill pipe or coiled tubing). The drilling assembly includes a bottom hole assembly (BHA) and a drill bit. The bottom hole assembly preferably contains commonly used measurement-while-drilling sensors. The drill string also contains a variety of sensors for determining downhole various properties of the drilling fluid. Sensors are provided to determine density, viscosity, flow rate, clarity, compressibility, pressure and temperature of the drilling fluid at one or more downhole locations. Chemical detection sensors for detecting the presence of gas (methane) and H₂S are disposed in the drilling assembly. Sensors for determining fluid density, viscosity, pH, solid content, fluid clarity, fluid compressibility, and a spectroscopy sensor are also disposed in the BHA. Data from such sensors may is processed downhole and/or at the surface. Corrective actions are taken based upon the downhole measurements at the surface which may require altering the drilling fluid composition, altering the drilling fluid pump rate or shutting down the operation to clean wellbore. The drilling system contains one or more models, which may be stored in memory downhole or at the surface. These models are utilized by the downhole processor and the surface computer to determine desired fluid parameters for continued drilling. The drilling system is dynamic, in that the downhole fluid sensor data is utilized to update models and algorithms during drilling of the wellbore and the updated models are then utilized for continued drilling operations.

Claims

1. A drilling system for use in drilling a wellbore, said drilling system having a source supplying drilling fluid under pressure to the wellbore, comprising:

(a) a drill string having;

(i) a tubing adapted to extend from the surface into the wellbore;

(ii) a drilling assembly coupled to the tubing, said drilling assembly having a drill bit at an end thereof for drilling the wellbore; and

(b) a plurality of pressure sensors disposed spaced apart alone a selected segment of the drill string for providing pressure measurements along the wellbore segment during the drilling of the wellbore

(c) processor determining from the measurements of the plurality of the sensors pressure gradient over the segment, said processor further determining from the pressure gradient presence one of (i) of a kick in the wellbore and (ii) condition of a reservoir adjacent the wellbore, during drilling of the wellbore.

2. The drilling system according to claim 1, wherein the processor determines the presence of the kick from a sudden change in pressure between adjacent pressure sensors along the wellbore segment and by correlating said pressure measurements with at least one geological parameter.

3. The drilling system of claim 2 wherein the selected segment is one of (a) a section extending along the wellbore, (b) a section circumferentially disposed along the drill string.

4. The drilling system of claim 1 further comprising a plurality of temperature sensors carried by the drill string providing a temperature gradient of the wellbore fluid during drilling of the wellbore.

5. The drilling system of claim 4 wherein the processor determines condition of a reservoir surrounding the wellbore by utilizing measurements from said pressure and temperature sensors.

6. A drill string for use in drilling of a wellbore, said wellbore filled with a drilling fluid during drilling of the wellbore, comprising:

(a) a tubing adapted to extend from the surface into the wellbore;

(b) a drilling assembly coupled to the tubing, said drilling assembly having a drill bit at an end thereof for drilling the wellbore; and

(c) a sensor carried by the drill string for determining a property of the drilling fluid downhole during the drilling of the wellbore, said sensor selected from a group of sensors consisting of (i) a sensor for determining density of a fluid sample;

(ii) an acoustic sensor for determining density of the drilling fluid flowing through an annulus;

(iii) an acoustic sensor for determining characteristics of cuttings in the drilling fluid;

(iv) a sensor for determining viscosity of the drilling fluid;

(v) a sensor for determining lubricity;

(vi) a sensor for determining compressibility;

(vii) a sensor for determining clarity of the drilling fluid;

(viii) a sol-gel device for determining chemical composition of the drilling fluid;

(ix) a fiber-optic sensor for determining a chemical property of the drilling fluid;

(x) a spectrometer for determining a selected parameter of the drilling fluid;

(xi) a sensor adapted to measure force required by a member to move over said drilling fluid; and

(xii) a sensor for determining influx of the formation fluid into the wellbore.

7. A method of determining at a downhole location the relative amount of a selected component material included in a drilling fluid supplied from a surface source to a wellbore during the drilling of said wellbore, comprising:

(a) tagging a known quantity of the selected component material into the drilling fluid;

(b) adding the tagged component material to the drilling fluid and thereafter supplying said drilling fluid with the tagged component material to the wellbore during the drilling of the wellbore; and

(c) taking measurements downhole of a parameter representative of the relative amount of the tagged component material in the drilling fluid by a sensor disposed in the wellbore.

8. The method of claim 7, wherein the chemical structure of the component material includes a hydrogen atom.

9. The method of claim 7 further comprising processing said measurements to determine the relative amount of the tagged material in the wellbore.

10. The method of claim 9 wherein said processing is done at least in part downhole.

11. The method of claim 9 further comprising determining the difference between the relative amount of the tagged component material determined from the downhole measurements and the relative amount of the tagged material added at the surface and adjusting the amount of such component material added to the drilling fluid if said difference is greater than a predetermined value.

12. A system for monitoring a parameter of interest of a drilling fluid in a wellbore during drilling of the wellbore, comprising:

(a) a downhole tool for use in the drilling of the wellbore; and

(a) a spectrometric device carried by the downhole tool, said spectrometric device comprising;

an energy source supplying a selected form of energy;

at least one sensing element exposed to the drilling fluid, said sensing element providing signals responsive to the supplied energy representative of the parameter of interest; and

a spectrometer for processing the signals from the sensing element to determine the parameter of interest.

13. The method of claim 12 wherein the spectrometric device includes:

(i) a light source;

(ii) an acousto-optical tunable filter-based monochromator; and

(iii) an optical detector to detect reflected radiations.

14. The downhole tool of claim 13 wherein the spectrometric device is tuned to detect presence of a particular chemical in the drilling fluid.

15. The system of claim 12 wherein the parameter of interest is one of (a) presence of a hydrocarbon of interest in the drilling fluid, (b) presence of water in the drilling fluid, (c) amount of solids in the drilling fluid, (d) density of the drilling fluid, (e) composition of the drilling fluid downhole, (f) pH of the drilling fluid, and (g) presence of H₂S in the drilling fluid.

16. The system of claim 12 wherein the selected energy is one of visible light, infrared, near infrared, ultraviolet, radio frequency, electromagnetic energy, and nuclear energy.

17. The system of claim 12 wherein the at least one sensing element includes at least two sensing elements for determining the parameter of interest of the drilling fluid in the downhole tool and in an annulus between the downhole tool and the wellbore.

18. The downhole tool of claim 12 wherein the processing is done at least in part downhole during drilling of the wellbore.

19. A downhole tool for use in drilling of a wellbore utilizing drilling fluid during said wellbore, said downhole tool comprising at least one fiber optic sensor providing measurements for an operating parameter of the drilling fluid during the drilling of the wellbore, said sensor being one of (i) a chemical sensor, and (ii) a radiation spectrometer.

20. A downhole tool for use in drilling a wellbore wherein a drilling fluid supplied from a surface location passes through the downhole tool and circulates through an annulus between the downhole tool and the wellbore during drilling of said wellbore, comprising said viscosity measuring device providing signals representative of the viscosity of the drilling fluid at a selected downhole location in the wellbore during drilling of the wellbore.

21. The downhole tool of claim 20 wherein the viscosity measuring device includes a pair of plates that receive a sample of the drilling fluid therebetween and provide signals corresponding to friction between the pair of the plates when said plates are moved relative to each other, the signals representing a measure of the viscosity of the drilling fluid at the selected downhole location.

22. The downhole tool of claim 20 further comprising a processor that processes signals from the viscosity measuring device at least in part downhole to determine the viscosity of the drilling fluid during drilling of the wellbore.

23. The downhole tool of claim 20 wherein the viscosity measuring device further includes a control valve for controlling supply of the drilling fluid to the viscosity measuring device.

24. The drilling system claim 23 wherein a processor controls the control valve for controlling the supply of the drilling fluid of the viscosity measuring device.

25. The downhole tool of claim 21 further comprising:

(i) a temperature sensor for providing temperature measurements of the drilling fluid in the wellbore;

(ii) a pressure sensor for providing pressure measurement of the drilling fluid in the wellbore; and

wherein the processor in response to the temperature and pressure measurements determines the viscosity of the drilling fluid at the measured temperature and the pressure.

26. The downhole tool of claim 20 wherein the viscosity measuring device is selected from a group consisting of (i) a device measuring friction produced between two plates moving relative to each other and having the drilling fluid therebetween;

and (ii) a rotating viscometer.

27. The drilling system of claim 26 wherein the processor processes the signals from the viscosity measuring device (i) at least in part downhole;

or (ii) at the surface.

28. The drilling system of claim 26 further comprising:

(i) a temperature sensor for providing temperature measurement of the drilling fluid in the wellbore;

(ii) a pressure sensor for providing pressure of the drilling fluid in the wellbore; and

wherein the processor in response to the temperature and pressure measurements determines the viscosity of the drilling fluid at the measured temperature and the pressure.

29. A drilling system for use in drilling of a wellbore, comprising:

(a) a tubing extending from a surface location into the wellbore;

(b) a source of drilling fluid supplying the drilling fluid under pressure into the tubing, said drilling fluid circulating to the surface via an annulus between the tubing and the wellbore;

(c) a drilling assembly at a bottom end of the tubing, said drilling assembly including;

(i) a drill bit for disintegrating rock formations surrounding the wellbore into cuttings, said cuttings flowing to the surface with the drilling fluid circulating through the annulus;

(ii) a viscosity measuring device providing signals representative of the viscosity of the drilling fluid at a selected downhole location; and

(iii) a processors for processing signals from the viscosity measuring sensor to determine the viscosity of the drilling fluid at the selected downhole location during drilling of the wellbore.

30. The drilling system of claim 29 wherein the viscosity measuring device includes a pair of members wherein at least one member is moved relative to the other member by one of (i) a hydraulic device;

and (ii) an electric device.

31. A method of drilling a wellbore with a drill string extending from a surface location into the wellbore, the drill string including tubing extending from the surface and into the wellbore, a drilling assembly carrying a drill bit attached to the tubing, said drill bit disintegration earth formation into cuttings during drilling of the wellbore, said method comprising:

(a) supplying a drilling fluid under pressure into toe tubing, said drilling fluid collecting cuttings and circulating to the surface via an annulus between the drill string and the wellbore;

(b) providing a density measuring device in the drilling assembly for providing signals representative of the viscosity of the drilling fluid at a selected downhole location in the wellbore; and

(c) processing signals from the viscosity measuring device to determine the density of the drilling fluid at the selected downhole location.

32. The method of claim 31 wherein the processing is done at least in part downhole by a processor carried by the drilling assembly.

33. The method of claim 31 further comprising comparing the viscosity of the drilling fluid determined from the viscosity measuring device signals with a desired drilling fluid viscosity at the selected downhole location.

34. The method of claim 33 further comprising altering the viscosity of the drilling fluid supplied under pressure from the surface in response to the comparison of the drilling fluid viscosity.

35. A downhole tool for use in drilling of a wellbore wherein a drilling fluid supplied from a surface source passes through the tool, circulates through the wellbore and returns to the surface during drilling of the wellbore, said downhole tool including a density measuring device for providing signals representative of the density of the drilling fluid at a selected downhole location in the wellbore during drilling of the wellbore.

36. The downhole tool of claim 35 further comprising a processor for processing, at least in part downhole, the signals from the density measuring device to determine the density of the drilling fluid at the selected downhole location in the wellbore during the drilling of the wellbore.

37. The downhole tool of claim 35 wherein the density measuring device includes (i) a chamber for holding a column of the drilling fluid;

and (ii) a sensor that provides differential pressure of the column of the drilling fluid.

38. The downhole tool of claim 35 wherein the density measuring device further includes a fluid control valve that controls flow of the drilling fluid into the chamber.

39. The downhole tool of claim 37 wherein the drilling fluid in the chamber is one of (i) drilling fluid with drilling cutting;

and (ii) drilling fluid substantially free of the drill cuttings.

40. The downhole tool of claim 35 wherein the density measuring device comprises a sonic sensor for determining the density of the drilling fluid downhole.

41. The downhole tool of claim 36 further comprising:

(i) a temperature sensor for providing temperature measurements of the drilling fluid in the wellbore;

(ii) a pressure sensor for providing pressure of the drilling fluid in the wellbore; and

wherein the processor in response to the temperature and pressure measurements determines the density of the drilling fluid at the measured temperature and the pressure.

42. A drilling system for use in drilling of a wellbore, comprising:

(a) a tubing extending from a surface location into the wellbore;

(b) a source of drilling fluid supplying the drilling fluid under pressure into the tubing, said drilling fluid circulating to the surface via annulus between the tubing and the wellbore;

(c) a drilling assembly at a bottom end of the tubing, said drilling assembly including;

(i) a drill bit for disintegrating rock formations surrounding the wellbore into cuttings, said cuttings flowing to the surface with the drilling fluid circulating through the annulus;

(ii) a density measuring device providing signals representative of the density of the drilling fluid at a selected downhole location; and

(iii) a processors for processing signals from the density measuring sensor to determine the density of the drilling fluid at the selected downhole location during drilling of the wellbore.

43. The drilling system of claim 42 wherein the density measuring device is selected from a group consisting of:

(i) a device that determines differential pressure of a column of the drilling fluid in the wellbore during drilling of the wellbore; and

(ii) an acoustic sensor.

44. The drilling system of claim 42 wherein the processor processes the density sensor signals at least in part downhole to determine the density of the drilling fluid.

45. The drilling system of claim 42 wherein the processor is located at the surface and comprises a computer.

46. A method of drilling a wellbore with a drill string extending from a surface location into the wellbore, the drill string including a tubing extending from the surface to the wellbore, and a drilling assembly carrying a drill bit attached to the tubing, said drill bit disintegration earth formation surrounding the wellbore into cuttings during drilling of the wellbore, said method comprising:

(a) supplying a drilling fluid under pressure to the tubing, said drilling fluid collecting cuttings and circulating said cuttings to the surface via an annulus between the drill string and the wellbore;

(b) providing a density measuring device in the drilling assembly for providing signals representative of the density of the drilling fluid at a selected downhole location in the wellbore; and

(c) processing signals from the density measuring device to determine the density of the drilling fluid at the selected downhole location.

47. The method of claim 46 wherein the processing is done at least in part downhole by a processor carried by the drilling assembly.

48. The method of claim 46 further comprising comparing the density of the drilling fluid determined from the density measuring device signals with a desired drilling fluid density at the selected downhole location.

49. The method of claim 48 further comprising altering the density of the drilling fluid supplied under pressure from the surface in response to the comparison of the drilling fluid density.

50. The method of claim 46 further comprising determining from the measurement of the density of the drilling fluid at the selected downhole location at least one of (i) gas contamination in the drilling fluid;

(ii) solids contamination in the drilling fluid;

(iii) barite sag in the drilling fluid; and

(iv) a measure of the effectiveness of transportation of the drill cuttings by the drilling fluid.

51. The method of claim 46 further comprising:

(i) determining temperature of the drilling fluid downhole;

(ii) determining pressure of the drilling fluid downhole; and

(iii) processing signals from the density measuring device to determine the density of the drilling fluid at the downhole measured temperature and pressure.

52. A downhole tool for use in drilling of a wellbore wherein a drilling fluid supplied from a surface source passes through the tool, circulates through the wellbore and returns to the surface during drilling of the wellbore, said downhole tool including a compressibility measuring device for providing signals representative of the compressibility of the drilling fluid at a selected downhole location in the wellbore during drilling of the wellbore.

53. The downhole tool of claim 52 wherein the compressibility measuring device includes a chamber for receiving the drilling fluid and a piston for compressing the fluid in the chamber, said compressibility measuring device providing signals representative of the movement of the piston.

54. The downhole tool of claim 52 further comprising a processor for determining compressibility of the drilling fluid from the signals provided by the compressibility measuring device.

55. The downhole tool of claim 54 further comprising a telemetry system for transmitting signals representative of the compressibility of the drilling fluid to a surface location.

56. The method of claim 54 further comprising determining from the compressibility of the drilling fluid presence of gas in the drilling fluid and thereby kick in the wellbore.

57. The method of claim 56 further comprising taking a corrective action upon determination of the kick in the wellbore.

58. A method of determining compressibility of drilling fluid downhole during drilling of a wellbore, comprising:

(a) drilling the wellbore with a drilling assembly by circulating through the wellbore a drilling fluid supplied under pressure from a surface location;

(b) providing a compressibility measuring device for providing signals representative of the compressibility of the drilling fluid downhole; and

(c) processing the compressibility device signals to determine the compressibility of the drilling fluid.

59. The method of claim 58 wherein said processing includes processing the signals by a processor, at least in part downhole, during drilling of the wellbore.

60. The downhole tool of claim 59 further comprising a processor for processing, at least in part downhole, the signals from the clarity measuring device to determine the clarity of the drilling fluid at the selected downhole location in the wellbore during the drilling of the wellbore.

61. The downhole tool of claim 60 wherein the processor determines the clarity substantially continuously.

62. A downhole tool for use in drilling a wellbore wherein a drilling fluid supplied from a surface source passes through the tool and circulates through the wellbore and returns to the surface during drilling of the wellbore, said downhole tool including a clarity measuring device for providing signals representative of the clarity of the drilling fluid at selected downhole location in the wellbore during drilling of the wellbore.

63. The downhole tool of claim 62 wherein the clarity measuring device is an optical device.

64. The downhole tool of claim 63 wherein the clarity measuring device includes a light source transmitting light through a body of the drilling fluid in the wellbore to provide measurements representative of the clarity of the drilling fluid during drilling of the wellbore.