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United States Patent  [ii] Patent Number: 4,823,594
Gray  Date of Patent: Apr. 25, 1989
 CONTAINER FOR A FLUID TO BE TESTED UNDER PRESSURE
 Inventor: Dennis W. Gray, Comanche, Okla.
 Assignee: Halliburton Company, Duncan, Okla.
 Appl. No.: 167,830
 Filed: Mar. 14, 1988
 Int. CI.* G01N 11/10
 U.S. Q 73/54; 73/59
 Field of Search 73/59, 54; 92/93, 96,
92/98 R, 99, 100, 105
 References Cited
U.S. PATENT DOCUMENTS
2,096,222 10/1937 Bock 265/11
2,122,765 7/1938 Weiler 265/11
2,266,733 12/1941 Bays et al 265/11
2,626,786 1/1953 McGlothlin 259/8
3,027,756 4/1962 Head 73/53
3,285,057 11/1966 De Zurik 73/59
3,402,729 9/1968 Richmond et al 137/92
3,636,753 1/1972 Thiele et al 73/59
3,751,975 8/1973 Katsura 73/59
4,175,425 11/1979 Brookfield 73/59
4,175,590 11/1979 Grandclement 92/98 R
4,430,889 2/1984 Sutton 73/61.4
4,466,276 8/1984 Royak et al 73/54
4,653,313 3/1987 Sabins et al 73/61.4
4,668,911 5/1987 Mueller et al 324/208
FOREIGN PATENT DOCUMENTS
1184119 12/1964 Fed. Rep. of Germany 73/59
2920084 11/1980 Fed. Rep. of Germany .
568869 11/1977 U.S.S.R. .
594438 2/1978 U.S.S.R. .
650009 4/1979 U.S.S.R. .
670855 6/1979 U.S.S.R. .
Primary Examiner—Michael J. Tokar
Assistant Examiner—M. Simons
Attorney, Agent, or Firm—Mark E. McBurney; E.
Gilbert Harrison, III
A slurry container for use in a consistometer to test a cement slurry includes a cup and a sealed pressure communicating structure. The sealed pressure communicating structure includes a baffle plate, a thermocouple well threadedly connected to an internal surface of a neck portion of the baffle plate, and a diaphragm extending radially between an outer surface of the neck portion of the baffle plate and an inner surface of the cup and longitudinally between facing surfaces of the baffle plate and a flange of the thermocouple well. A paddle is mounted on a shaft which is pivoted between the lower end of the thermocouple well and the bottom of the cavity defined in the cup. Magnets are mounted on the paddle to provide magnetic coupling across the sealed boundary defined by the baffle plate, thermocouple well and diaphragm assembly.
16 Claims, 2 Drawing Sheets
CONTAINER FOR A FLUID TO BE TESTED
BACKGROUND OF THE INVENTION 5
This invention relates generally to a container for a fluid to be tested under pressure and more particularly, but not by way of limitation, to a positive sealed slurry cup for a consistometer.
In the oil and gas industry, different fluids are used 10 for various purposes in drilling and completing a well. For example, batches of cement slurry must be mixed and pumped into the well for cementing casing into the well bore. The cement is generally pumped through the casing and up the annulus between the casing and the 15 well bore to create the necessary bond.
Because different batches of fluids (e.g., cement slurries) can have different characteristics which affect how the fluids perform in the high temperature and high pressure environments found downhole, there is the 20 need for equipment which can test a fluid sample prior to the fluid being pumped downhole so that one can determine if that particular batch of fluid has the proper characteristics for the particular situation. Such a type of equipment, known as a consistometer or viscometer, 25 is known to the art.
To pressurize the fluid under test in a consistometer of a type known to the art, a pressurized fluid is applied to one side of a sealed boundary separating the pressurized fluid from the test fluid. Not only must a seal be 30 provided at this boundary, but also a sealed passageway through the seal must be provided to receive a paddle shaft or a tube in which a thermocouple is housed for monitoring the temperature of the test fluid. Heretofore, this passageway has been provided through one or 35 more diaphragms or plates sealing directly around the shaft or tube. These diaphragms or plates extend across the annulus between the outside of the tube or shaft and the inside of the cup in which the test fluid is held. A diaphragm and bushing construction wherein O-rings 40 carried by the bushing seal against the tube or shaft has also been used.
A shortcoming of these types of constructions is that when enough air bubbles are contained within the test fluid, the diaphragms or seal rings or plates of these 45 prior constructions tend to collapse or deform toward the test fluid when the pressurized fluid is applied. This collapsing or deforming can break the seal formed at the edge where the seal member is to engage the tube or shaft extending therethrough, thus allowing the pressur- 50 ized fluid to leak into the chamber where the test fluid is. The pressurized fluid, such as mineral oil, can contaminate the test fluid or can create a thin film on the inner surface of the cup containing the test fluid. This contamination or film can adversely affect the accuracy 55 of the pumping time or viscosity analyses which were intended to be made.
Another noted shortcoming of these constructions which attempt to seal around a rotatable shaft is that excess friction may result when the shaft is rotated, such 60 as in response to increasing viscosity of the test fluid, for example.
Therefore, there is the need for a new container for a fluid to be tested under pressure wherein the test fluid is more positively isolated from the pressure medium 65 while still being able to rotate or detect the rotation of a paddle through the test fluid and while also still being able to receive a thermocouple for monitoring the tem
perature of the test fluid. Such a container should be specifically useful for high pressure, high temperature cement slurry testing consistometers.
SUMMARY OF THE INVENTION
The present invention overcomes the above-noted and other shortcomings of the prior art by providing a novel and improved container for a fluid to be tested under pressure. In the preferred embodiment, the present invention more positively isolates a cement slurry from a pressure medium and yet detects or imparts rotation of a paddle disposed in the cement slurry and monitors the temperature of the slurry.
The container of the present invention comprises: a cup having defined therein a cavity for receiving a fluid to be tested under pressure; a first member retained within the cup near a mouth of the cavity, the first member including a neck portion extending toward a closed end of the cavity, the neck portion having an outer surface; a second member retained within the cavity so that at least a part of the second member is disposed within the neck portion of the first member, the second member including a flange adjacent the neck portion and extending beyond the outer surface of the neck portion; and seal means for providing a seal from adjacent the neck portion of the first member and the flange of the second member to the cup so that the seal means is between the first member and the closed end of the cavity to separate a pressurizing medium, communicated through the first member to the seal means, from a fluid received in the cavity to be tested under the pressure exerted by the pressurizing medium.
In the preferred embodiment the neck portion of the first member has a cylindrical, threaded inner surface defining a throat through the neck portion. The first member also includes an annular disk portion which extends radially outwardly from an end of the neck portion. The second member further includes a tube including an open end and a closed end, which open end has a threaded outer surface engaged with the threaded inner surface of the neck portion of the first member and which open end has the flange of the second member extending therefrom adjacent the threaded outer surface. The closed end of the tube is disposed in the cavity of the cup. A diaphragm included in the seal means includes a hub disposed around the outer surface of the neck portion of the first member and between the annular disk portion of the first member and the flange of the second member.
The container further comprises a paddle and a shaft. The paddle includes a paddle frame, first center support means for supporting the paddle frame and for receiving a portion of the second member, and second center support means for supporting the first center support means and the paddle frame. The shaft is retained in the second center support means so that a first end of the shaft extends therefrom into pivotal engagement with the portion of the second member received into the first center support means and further so that a second end of the shaft extends therefrom into pivotal engagement with the cup at the closed end of the cavity. In the preferred embodiment, the container still further comprises at least one magnet mounted on the paddle frame.
Using one or more magnets on the paddle along with attracting magnet(s) mounted opposite the paddle magnet(s) on a viscosity measuring device or a paddle rotating system, whereby the boundary between the test