Cement expansion/contraction test apparatus

• US 6,817,238 B2
• Filed: 06/21/2002
• Issued: 11/16/2004
• Est. Priority Date: 06/22/2001
• Status: Expired due to Term

• Current Assignee: Western Atlas Holdings LLC (Baker Hughes Company)
• Original Assignee: BJ Services Company
• Inventors: Go Boncan, Virgilio C., Bray, W. Scott
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): Rogers, David A.
• Application Number:
  US10/177,742
• Publication Number:
  US 20030033893A1
• Time in Patent Office: 879 Days
• Field of Search: 731/49, 734/29, 738/656, 738/645--86, 738/66, 738/03, 249/66.1, 249/67, 249/82, 249/117, 249/126, 249/155, 249/158, 249/163, 249/165, 264/140.4, 264/40.5, 264/40.7, 264/288, 374/55, 374/56
• US Class Current: 73/149
• CPC Class Codes: G01N 33/383 Concrete or cement

Abstract

An apparatus for measuring volumetric changes in cement as the cement is exposed to pressures and temperatures to simulate down-hole conditions, in a high-pressure high-temperature chamber is described. The apparatus is described as a mold having a first section adjacent a base and a second section movably attached to the first section and adjacent the base in which cement may be placed. The apparatus includes a sensor to measure the movement of the first and second sections relative to one another in response to volumetric changes in the cement. Also described is a method of measuring the volumetric changes in cement as the cement is exposed to simulated down-hole pressures and temperatures in a high-pressure, high-temperature chamber.

Claims

1. An apparatus for measuring volumetric changes in cement as the cement is being exposed to a given pressure and temperature in a high-pressure high-temperature chamber, comprising:

a first section adjacent a base, the first section functionally associated with a first anchor block;

a second section functionally associated with the first section,

the second section adjacent the base,

the first section, the second section, and the base defining a mold into which a measurable amount of cement may be placed, the second section functionally associated with a second anchor block; and

a sensor adapted to measure the movement of the first and second sections relative to one another in response to volumetric changes in the cement when the cement is exposed to simulated down-hole pressures and temperatures,

wherein the first anchor block is adapted to move with respect to the first section and the second anchor block is adapted to move with respect to the second section in response to volumetric changes of the cement when the cement is exposed to simulated down-hole pressures and temperatures.

2. The apparatus of claim 1 further comprising a seal between the first section and the second section.

3. The apparatus of claim 2 in which the seal is an O-ring.

4. The apparatus of claim 2 in which the seal is thin wall tubing.

5. The apparatus of claim 1 in which the second section is movably attached to the first section by a fastening assembly.

6. The apparatus of claim 5 in which the fastening assembly further comprises:

a first bolt surrounded by a first spring and having a threaded end, the first bolt passing through a first hole in the second section and threadedly engaged with a first threaded hole in the first section; and

a second bolt surrounded by a second spring and having a threaded end, the second bolt passing through a second hole in the second section and threadedly engaged with a second threaded hole in the first section, the springs adapted to bias the second section into contact with the first section.

7. The apparatus of claim 6 in which the fastening assembly further comprises two alignment pins, each alignment pin adapted to engage in holes in the first and second sections.

8. The apparatus of claim 1 in which the first section is comprised of two substantially straight sides at a first angle, each side also having a mating surface to be associated with the second section.

9. The apparatus of claim 8 in which the second section is comprised of two substantially straight sides at a second angle, each side also having a mating surface to be associated with the mating surfaces of the first section to movably attach the first and second sections.

10. The apparatus of claim 9 in which the first and second angles are 90 degrees.

11. The apparatus of claim 9 in which the sensor contacts the second section at a contact location.

13. The apparatus of claim 1 in which the sensor is a linear displacement transducer.

14. The apparatus of claim 13 in which the linear displacement transducer is a spring loaded displacement transducer.

15. The apparatus of claim 13 in which the linear displacement transducer is an electromagnetic linear displacement transducer.

16. The apparatus of claim 13 in which the sensor is connected to a data acquisition unit connected to a device to store data from the sensor over time.

17. The apparatus of claim 16 in which the device is a chart recorder.

18. The apparatus of claim 16 in which the device is a computer.

19. The apparatus of claim 1 in which the first section, the second section, and the base each are comprised of brass.

20. The apparatus of claim 1 further comprising:

a plurality of molds,

a third section fixedly attached to a second base,

a fourth section movably attached to the third section, the fourth section resting on the second base,

the third section, the fourth section, and the second base defining a second of the plurality of molds into which a given amount of cement may be placed; and

a plurality of first sensors, each first sensor functionally associated with one given mold of the plurality of molds, one of the plurality of first sensors adapted to measure the movement between the third and fourth sections of the second mold in response to volumetric changes in the cement when the cement is exposed simulated downhole conditions.

21. The apparatus of claim 20 further comprising a basket, the basket having a bottom plate connected to a top plate by a plurality of mounting rods, the plurality of molds being located between the bottom plate and the top plate.

22. The apparatus of claim 21 further comprising a handle attached to the top plate to allow the basket to be moved.

23. The apparatus of claim 21 wherein the bottom plate is connected to the mounting rods via nuts and the top plate is connected to the mounting rods via nuts.

24. The apparatus of claim 21 wherein each mold further comprises a lid having a portion defining at least one hole to accommodate the mounting rods;

and a base having a portion defining at least one hole to accommodate the mounting rods.

25. The apparatus of claim 24 wherein at least one base is functionally associated with the mounting rods via a flange.

26. The apparatus of claim 25 wherein a first mold is adjacent the bottom plate of the basket and a second mold positioned substantially above the first mold in the basket, the second mold being functionally associated with the mounting rods via the flange to define a gap between the base of the second mold and the lid of the first mold, the gap allowing the cement within the first mold to expand vertically.

27. The apparatus of claim 26 wherein a third mold is positioned substantially above the second mold in the basket, the third mold being functionally associated with the mounting rods via the flanges to define a gap between the base of the third mold and the lid of the second mold, the gap allowing the cement within the second mold to expand vertically.

28. The apparatus of claim 27 wherein the top plate of the basket is positioned substantially above the third mold, the top plate being functionally associated with the rods to define a gap between the lid of the third mold and the top plate, the gap allowing the cement within the third mold to expand vertically.

29. The apparatus of claim 21 wherein a plurality of types of cement are placed into the plurality of molds.

30. The apparatus of claim 1 in which the first section has a first channel adapted to receive the first anchor block and the second section has a second channel adapted to receive the second anchor block.

31. The apparatus of claim 30 in which the first anchor block has a first anchor bolt and the second anchor block has a second anchor bolt, the cement attaching to each anchor bolt once the cement is set.

32. The apparatus of claim 31 comprising a seal between the first section and the second section, the seal adapted to compress when the cement contracts, the contraction of the cement moving second section toward the first section as the cement is attached to the first and second anchor bolts, to compress the seal.

33. The apparatus of claim 32 further comprising the first section having two substantially straight sides at a first angle, each side of the first section also having a mating surface to be associated with the second section, the second section having two substantially straight sides at a second angle, each side of the second section also having a mating surface to be associated with the mating surfaces of the first section, to movably attach the first and second sections.

34. The apparatus of claim 1 wherein the mold is also adapted to allow the cement to expand vertically.

35. The apparatus of claim 1 further comprising a lid being movably attached to the first and second section allowing the cement to expand vertically.

12. An apparatus for measuring volumetric changes in cement as the cement is exposed to a given pressure and temperature in a high-pressure high-temperature chamber, comprising:

a first section adjacent a base;

a second section movably attached to the first section, the second section adjacent the base, the first section, the second section, and the base defining a mold into which a measurable amount of cement may be placed, the first section having two substantially straight sides at a first angle, each side of the first section also having a mating surface to be associated with the second section, the second section having two substantially straight sides at a second angle, each side of the second section also having a mating surface to be associated with the mating surfaces of the first section, to movably attach the first and second sections;

a first channel in the first section adapted to receive a first anchor block having a first anchor bolt;

a second channel in the second section adapted to receive a second anchor block having an second anchor bolt, the cement attaching to each anchor bolt once the cement is set,

wherein the first anchor block moves with respect to the first section and the second anchor block moves with respect to the second section in response to changes in volume of the cement; and

a sensor adapted to measure the movement of the first and second sections relative to one another in response to volumetric changes in the cement when the cement is exposed to simulated down-hole pressures and temperatures.

50. The apparatus of claim 12, 36, or 45 in which the first and second angles each comprise ninety degrees.

51. The apparatus of claim 12, 36, or 45 in which the sensor is a linear displacement transducer.

36. An apparatus for measuring volumetric changes in cement as the cement is exposed to a given pressure and temperature in a high-pressure high-temperature chamber, comprising:

a first section adjacent a base;

a second section adjacent the base and movably attached to the first section,

the first section, the second section, and the base defining a mold into which a measurable amount of cement may be placed;

a sensor adapted to continuously measure the movement of the first and second sections relative to one another in response to volumetric changes in the cement when the cement is exposed to simulated down-hole pressures and temperatures; and

a lid functionally associated with the first and second sections to enclose the mold, the lid being movably attached to the first and second section allowing the cement to expand vertically.

37. The apparatus of claim 36 in which the first section, the second section, the lid, and the base each are comprised of brass.

38. The apparatus of claim 36 further comprising a seal between the lid and the first and second sections.

39. The apparatus of claim 38 further comprising a fastening assembly to movably attach the lid to the first section and second section, the fastening assembly having:

a first bolt surrounded by a first spring and having a threaded end, the first bolt passing through a first hole in the second section and threadedly engaged with a first threaded hole in the first section; and

a second bolt surrounded by a second spring and having a threaded end, the second bolt passing through a second hole in the second section and threadedly engaged with a second threaded hole in the first section, the springs adapted to bias the second section into contact with the first section.

40. The apparatus of claim 36 further comprising a second sensor contacting the lid adapted to measure the movement of the lid relative to the first and second sections.

47. The apparatus of claim 36 or 45 further comprising a seal between the first section and the second section.

48. The apparatus of claim 36 or 45 in which the second section is movably attached to the first section by a fastening assembly.

49. The apparatus of claim 36 or 45 in which the first section is comprised of two substantially straight sides at a first angle, each side of the first section also having a mating surface to be associated with the second section, and the second section being comprised of two substantially straight sides at a second angle, each side of the second section also having a mating surface to be associated with the mating surfaces of the first section to movably attach the first and second sections.

41. An apparatus for measuring volumetric changes in cement as the cement is exposed to a given pressure and temperature in a high-pressure high-temperature chamber, comprising:

a first section adjacent a base, the first section functionally associated with a first anchor block having a first bolt;

a second section functionally associated with the first section,

the first section, the second section, and the base defining a mold into which a measurable amount of cement may be placed, the second section adjacent the base and functionally associated with a second anchor block; and

a sensing means for continuously measuring the movement of the first and second sections relative to one another in response to volumetric changes in the cement as the cement is exposed to simulated downhole pressures and temperatures, wherein the first anchor block is adapted to move with respect to the first section and the second anchor block is adapted to move with respect to the section when the cement is exposed to simulated down-hole pressures and temperatures.

42. The apparatus of claim 41 further comprising:

means for sealing the first section and the second section; and

means for movably attaching the second section to the first section.

43. The apparatus of claim 41 further comprising a seal between the first section and the second section.

44. The apparatus of claim 41 in which the first section is comprised of two substantially straight sides at a first angle, each side of the first section also having a mating surface to be associated with the second section, and the second section being comprised of two substantially straight sides at a second angle, each side of the second section also having a mating surface to be associated with the mating surfaces of the first section to movably attach the first and second sections.

45. An apparatus for measuring volumetric changes in cement as the cement is exposed to a given pressure and temperature in a high-pressure high-temperature chamber, comprising:

a first section adjacent a base;

a second section adjacent the base and movably attached to the first section,

the first section, the second section, and the base defining a mold into which a measurable amount of cement may be placed;

a sensor adapted to continuously measure the movement of the first and second sections relative to one another in response to volumetric changes in the cement when the cement is exposed to simulated down-hole pressure and temperatures; and

a first channel in the first section adapted to receive a first anchor block having a first anchor bolt, the cement attaching to the first anchor bolt once the cement is set; and

a second channel in the second section adapted to receive a second anchor block having a second anchor bolt, the cement attaching to the second anchor bolt once the cement is set,

wherein the first anchor block moves with respect to the first section and the second anchor block moves with respect to the second section in response to changes in volume of the cement.

46. The method of claim 45 wherein the mold is adapted to allow the cement to expand vertically.