Abstract:
A method and apparatus for monitoring lubricity consists of a cylindrical cell assembly ( 80 ) capable of withstanding high pressure and high temperature with a movable rotor ( 26 ) abrading a solid sample ( 28 ) while submerged in a liquid sample ( 74 ). A loading device ( 42 ) moves a bottom shaft ( 46 ) supporting the solid sample ( 28 ) as said solid sample ( 28 ) abrades and is moved upwards, and its movement is measured by a displacement sensor ( 40 ). Liquid sample ( 74 ) is drained through solid sample ( 28 ) into receiver ( 38 ) to measure filtration of solid sample ( 28 ). Heat is provided via a heater ( 64 ) and pressure is controlled via pressurization media ( 72 ).

Description:
BACKGROUND 
     1. Field of Invention 
     The present invention relates to apparatuses and methods for monitoring, measuring, or analyzing the lubricity of fluid samples in conjunction with solid samples. 
     2. Description of Prior Art 
     U.S. Pat. No. 6,105,415 describes a method and apparatus for testing the lubricity of a drilling mud. The test is accomplished by rotating a core sample so that it rubs against a metal surface (simulating a rotating pipe or drill string in a well) and then saturating the core sample and the metal surface with a drilling mud. The energy required to rotate the core sample while it is saturated with the drilling mud is determined and this measurement is used to determine the lubricity of the drilling mud. This design is specifically intended to simulate downhole conditions, and requires both a drilling fluid sample and a core sample, with the core sample being positioned at only one angle. This limits the test parameters that can be specified to a relatively narrow range. 
     U.S. Pat. No. 3,060,721 describes an apparatus for testing lubricants by measuring the change in electrical resistance provided by wear or attrition of a test specimen. The apparatus of this invention provides an eccentric rotating surface and means for supporting a strip-like test specimen so that at least a portion of the periphery of said eccentric rotating surface bears against and rubs the test specimen, and induces cyclic tensile stresses therein. The test specimen and rotating surface are enclosed in a suitable vessel which is provided with inlet and outlet means, such that a controlled corrosive environment can be caused to exist within the vessel. Means are provided for continuously applying lubricant to the contact surface between the strap-like test specimen and the rotating surface. This apparatus does not, however, provide the means to measure lubricity. The user must employ microscopic measurement to examine the specimen in order to determine the amount of wear, the results of which determination can in turn can be used to calculate the lubricity of a tested fluid. Alternatively, the user may employ an electrical resistance test on the abraded surface of the specimen, should the specimen be made of conductive metal. The test procedures required to use this invention as intended are time-consuming and onerous, and this substantially limits the scope and usefulness of the invention. 
     U.S. Pat. No. 3,913,377 describes a friction testing machine in which fluids may be tested for lubricity. A disc, rotated continuously by a variable-speed driving means, has friction members clamped against its opposite faces by means of a calibrated, adjustable mechanism which controls the “normal” force holding the members against the disc. The friction force between the members and the disc may be determined by measuring the tangential force produced on the members as the disc rotates. One edge of the disc dips into a bath of the lubricant being tested, to provide lubricant at the juxtaposed disc and member surfaces. A heating means may be provided for the bath, to enable testing at elevated temperatures. While again limiting the testing apparatus to operating only at one angle, this device limits the possible specimen types which might make up the disk to only those which are of a sufficiently solid consistency. 
     It is an object of this invention to create a device which can measure the lubricity of a fluid submerging two solid samples of various kinds. At least one of the solid samples could be a porous media, and the filtration of said fluid through said porous media could also be measured under varying and controllable conditions, including but not limited to those of temperature and pressure. 
     SUMMARY OF THE PRESENT INVENTION 
     A lubricity tester in accord with the present invention is comprised of a cylindrical pressure cell wherein a solid sample is pushed against and abraded by a rotating rotor while being saturated and infiltrated by a liquid sample, all under conditions of temperature and pressure. The device is constructed so that pressure can be applied which forces the liquid sample to filter through the solid sample and out of the pressure cell. The solid sample is attached to a displacement sensor, which measures the movement of the solid sample as it is worn away by the rotor. 
    
    
     
       DRAWING FIGURES 
       Other objects, features and advantages will be apparent from the following detailed description of the preferred embodiment taken in conjunction with accompanying drawings in which: 
         FIG. 1  is a cross-section view of lubricity tester  80  in the preferred embodiment of the invention. 
         FIG. 2  is a detailed close-up of the rotor and sample assembly in  FIG. 1 , with a circular drill bit. 
         FIG. 3  is a cross-section view of lubricity tester  80 B with a solid cone bit and a matching conical surface. 
         FIG. 4  is a detailed close-up of the rotor and sample assembly in  FIG. 3 . 
         FIG. 5  is a detailed close-up of a back pressure accumulator assembly replacing the receiver in  FIG. 1 . 
         FIG. 6  is a cross-section view of the lubricity tester  80 E with an rotating sample assembly. 
     
    
    
     REFERENCE NUMERALS IN DRAWINGS 
     
         
           8  Motor 
           8 A Motor 
           8 C Motor 
           10  Top shaft 
           10 A Top shaft 
           10 C Top shaft 
           12  Pressurization port 
           12 A Pressurization port 
           12 C Pressurization port 
           14  Bearing holder 
           14 A Bearing holder 
           14 C Bearing holder 
           16  Thread 
           16 A Thread 
           16 C Thread 
           18  O-ring 
           18 A O-ring 
           18 C O-ring 
           20  Sample cup 
           20 A Sample cup 
           20 C Sample cup 
           22  Thread 
           22 A Thread 
           22 C Thread 
           24  Hole 
           24 C Hole 
           26  Rotor 
           26 A Solid cone bit 
           26 C Ring 
           27  Abrasive circular drill bit 
           27 A Conical surface 
           28  Solid sample 
           28 A Concave solid sample 
           28 C Solid sample 
           29 A Central hole 
           34  Valve 
           34 A Valve 
           36  Tube 
           36 A Tube 
           36 B Tube 
           38  Receiver 
           38 A Receiver 
           40  Displacement sensor 
           40 A Displacement sensor 
           40 C Displacement sensor 
           42  Loading device 
           42 A Loading device 
           42 C Loading device 
           44  Tube fitting 
           44 A Tube fitting 
           46  Bottom shaft 
           46 A Bottom shaft 
           46 C Bottom shaft 
           48  Hole 
           48 A Hole 
           50  O-ring 
           50 A O-ring 
           50 C O-ring 
           54  Thread 
           54 A Thread 
           54 C Thread 
           56  Sample holder 
           56 A Sample holder 
           56 C Sample holder 
           58  Thread 
           58 A Thread 
           58 C Thread 
           60  Retainer 
           60 A Retainer 
           60 C Retainer 
           61  O-ring 
           61 A O-ring 
           62  Stirrer 
           64  Heater 
           64 A Heater 
           64 C Heater 
           66  O-ring 
           66 A O-ring 
           66 C O-ring 
           67  Snap ring 
           67 A Snap ring 
           67 C Snap ring 
           68  Bearing 
           68 A Bearing 
           68 C Bearing 
           69  Bearing spacer 
           69 A Bearing spacer 
           69 C Bearing spacer 
           70  Bearing 
           70 A Bearing 
           70 C Bearing 
           71  Snap ring 
           71 A Snap ring 
           71 C Snap ring 
           72  Pressurization media 
           72 A Pressurization media 
           72 C Pressurization media 
           74  Liquid sample 
           74 A Liquid sample 
           74 C Liquid sample 
           80  Lubricity tester 
           80 A Lubricity tester 
           80 C Lubricity tester 
           82 B Gas tube 
           84 B Piston 
           86 B Sensor 
           88 B Accumulator assembly 
       
    
     DESCRIPTION 
     FIG.  1 —Preferred Embodiment 
       FIG. 1  is a cross-section view of a lubricity tester  80  with a cylindrical sample cup  20  and a bearing holder  14 . Sample cup  20  is screwed onto bearing holder  14  via a thread  16 . A top shaft  10  passes through the center of bearing holder  14 , and is rotationally supported by a bearing  70 , a bearing  68 , a bearing spacer  69 , a snap ring  67 , and a snap ring  71 . An o-ring  66  assures against leakage through thread  16 . An o-ring  18  assures against leakage around top shaft  10 . 
     A rotor  26 , with a predominately ring shaped lower portion, is screwed onto the lower end of top shaft  10  via a thread  22 . Thus rotor  26  can co-axially rotate together with top shaft  10 . A stirrer  62  is fixed to the lower end of top shaft  10  and positioned inside rotor  26 . Sample cup  20  is partially filled with a pressurization media  72  and a liquid sample  74 . Liquid sample  74  submerges rotor  26  and is able to flow through rotor  26  through a hole  24 . Pressurization media  72  is introduced through a pressurization port  12 . 
     A solid sample  28 , which typically can be a porous rock or a solid, non-porous metal, is placed inside a sample holder  56 , which is attached to the top of a bottom shaft  46  via a thread  54 . Solid sample  28  is secured to sample holder  56  by a retainer  60 , which is screwed onto sample holder  56  via a thread  58 . An O-ring  61  assures against leakage from thread  58 . Liquid sample  74  saturates and infiltrates solid sample  28 . Bottom shaft  46  extends downward through the bottom of sample cup  20  and an O-ring  50  provides assurance against leakage. A loading device  42  pushes bottom shaft  46  upward so that solid sample  28  presses against rotor  26 , while the force applied on bottom shaft  46  is recorded, and the movement of bottom shaft  46  is recorded by a displacement sensor  40  as well. 
     A hole  48  in the center of bottom shaft  46  receives liquid sample  74  which has filtered through solid sample  28 . Hole  48  extends downward though the length of bottom shaft  46  and is connected to a tube fitting  44 . Tube fitting  44  connects to a valve  34 , which is further connected to a tube  36  which drains into a receiver  38 . Temperature control is provided by a heater  64  positioned radially outside the sample cup  20 . 
     Operation—FIG.  1 —Preferred Embodiment 
     In  FIG. 1 , to assemble lubricity tester  80 , place o-ring  18  into bearing holder  14 . Install bearing  68 , bearing spacer  69 , bearing  70 , snap ring  67  and snap ring  71  onto top shaft  10 . Insert top shaft  10  into bearing holder  14 . Install stirrer  62  onto the lower end of top shaft  10 . Screw rotor  26  onto top shaft  10  via thread  22 . Install o-ring  66  onto bearing holder  14 . 
     Install o-ring  50  onto bottom shaft  46 , then insert bottom shaft  46  into the bottom of sample cup  20 . Screw sample holder  56  onto the top of bottom shaft  46  via thread  54 . Install solid sample  28  into sample holder  56  and install o-ring  61  onto sample holder  56  to assure against leakage between solid sample  28  and sample holder  56 . Secure solid sample  28  by screwing retainer  60  into sample holder  56  via thread  58 . 
     Pour liquid sample  74  into sample cup  20 . Screw sample cup  20  onto bearing holder  14  via thread  16 . Apply upward force at bottom of bottom shaft  46  using loading device  42 , and displacement sensor  40  reads the movement of bottom shaft  46 . Loading device  42  forces solid sample  28  to press tightly against rotor  26 . 
     Connect tube fitting  44  to valve  34 , and insert tube  36  into receiver  38 . Inject pressurization media  72  through pressurization port  12 . Adjust temperature as desired by activating heater  64 . As top shaft  10  rotates, rotor  26  rotates and abrades against solid sample  28 , causing the surface of solid sample  28  to wear away. As it does so, loading device  42  will move bottom shaft  46  up, while recording the upward force applied on bottom shaft  46 . The power consumption and/or the torque value required to rotate shaft  10  is also recorded. Many means can be used to measure the torque on top shaft  10 , such as the direct reading of a strain gauge on top shaft  10 , the direct reading of torque from a motor  8  that drives top shaft  10 , or the indirect reading of the power consumption of motor  8  that drives top shaft  10 . The lubricity and/or the friction factor between solid sample  28  and rotor  26  is calculated from the torque on shaft  10  and the upward force applied to bottom shaft  46 . The displacement sensor  40  records the changes as solid sample  28  is abraded. 
     Liquid sample  74  is able to saturate and infiltrate solid sample  28  by flowing through hole  24  in rotor  26 . As liquid sample  74  is stirred by stirrer  62 , pressurization media  72  forces it to filter through solid sample  28 , whereupon it drains into hole  48 , if solid sample  28  is porous. Valve  34  can be opened to allow liquid sample  74  to drain into receiver  38 , allowing the measurement of the filtration value of solid sample  28  and liquid sample  74  under conditions of temperature and pressure. 
     Description 
     FIG.  2 —Abrasive Circular Drill Bit Embodiment 
       FIG. 2  is a cross-section view of another configuration of  FIG. 1 , in which rotor  26  is replaced with an abrasive circular drill bit  27 . Abrasive circular drill bit  27  is shaped to resemble a circular drill bit, as might be used in the petrochemical industry. This configuration would enable the simulation of real drilling processes under downhole conditions. It would also be capable of anticipating the penetration rate of a drill bit under downhole conditions. 
     Description 
     FIG.  3 —Solid Cone Bit Embodiment 
       FIG. 3  is a cross-section view of a lubricity tester  80 A with a sample cup  20 A and a bearing holder  14 A. Sample cup  20 A is screwed onto bearing holder  14 A via a thread  16 A. An o-ring  66 A assures against leakage through thread  16 A. A top shaft  10 A passes through the center of bearing holder  14 A, and is rotationally supported by a bearing  70 A, a bearing  68 A, a bearing spacer  69 A, a snap ring  67 A, and a snap ring  71 A. An o-ring  18 A assures against leakage around top shaft  10 A. 
     A solid cone bit  26 A is screwed onto the lower end of top shaft  10 A via a thread  22 A. Sample cup  20 A is partially filled with a pressurization media  72 A and a liquid sample  74 A. Liquid sample  74 A submerges solid cone bit  26 A. Pressurization media  72 A is introduced through a pressurization port  12 A. 
     A concave solid sample  28 A with a central hole  29 A and a conical surface  27 A is placed inside a sample holder  56 A, which is attached to the top of a bottom shaft  46 A via a thread  54 A. Concave solid sample  28 A is secured to sample holder  56 A by a retainer  60 A, which is screwed onto sample holder  56 A via a thread  58 A. An o-ring  61 A assures against leakage around concave solid sample  28 A. Liquid sample  74 A saturates and infiltrates concave solid sample  28 A. 
     Bottom shaft  46 A extends downward through the bottom of sample cup  20 A, and an o-ring  50 A provides assurance against leakage. Bottom shaft  46 A is connected at the bottom to a loading device  42 A and a displacement sensor  40 A. Loading device  42 A pushes bottom shaft  46 A upward so that conical surface  27 A in concave solid sample  28 A fits around and presses against solid cone bit  26 A. 
     A hole  48 A receives liquid sample  74 A which has filtered through concave solid sample  28 A. Hole  48 A extends downward through the length of bottom shaft  46 A and is connected to a tube fitting  44 A. Tube fitting  44 A connects to a valve  34 A, which is further connected to a tube  36 A which drains into a receiver  38 A. Temperature control is provided by a heater  64 A positioned radially around the outside of sample cup  20 A. 
     Operation—FIG.  3 —Solid Cone Bit Embodiment 
     In  FIG. 3 , to assemble lubricity tester  80 A, place o-ring  18 A into bearing holder  14 A. Install bearing  68 A, bearing spacer  69 A, bearing  70 A, snap ring  67 A and snap ring  71 A onto top shaft  10 A. Insert top shaft  10 A into bearing holder  14 A. Screw solid cone bit  26 A onto top shaft  10 A via thread  22 A. Install o-ring  66 A onto bearing holder  14 A. 
     Install o-ring  50 A onto bottom shaft  46 A, then insert bottom shaft  46 A into the bottom of sample cup  20 A. Screw sample holder  56 A onto the top of bottom shaft  46 A via thread  54 A. Install concave solid sample  28 A into sample holder  56 A. Install o-ring  61 A onto sample holder  56 A to assure against leakage between concave solid sample  28 A and sample holder  56 A. Secure concave solid sample  28 A by screwing retainer  60 A into sample holder  56 A via thread  58 A. Pour liquid sample  74 A into sample cup  20 A. Screw sample cup  20 A onto bearing holder  14 A via thread  16 A. Apply upward force at bottom of bottom shaft  46 A using loading device  42 A, and displacement sensor  40 A reads the movement of bottom shaft  46 A. Loading device  42 A forces concave solid sample  28 A to press tightly against solid cone bit  26 A. 
     Connect tube fitting  44 A to valve  34 A, and insert tube  36 A into receiver  38 A. Inject pressurization media  72 A through pressurization port  12 A. Adjust temperature as desired by activating heater  64 A. As a motor  8 A drives top shaft  10 A rotating, solid cone bit  26 A rotates and abrades against concave solid sample  28 A, causing conical surface  27 A of concave solid sample  28 A to wear away. As it does so, loading device  42 A will move bottom shaft  46 A up. The displacement sensor  40 A records the change. The lubricity and/or the friction factor between solid sample  28 A and rotor  26 A is calculated from the torque applied to shaft  10 A and the upward force applied to bottom shaft  46 A. 
     Liquid sample  74 A is able to saturate and infiltrate concave solid sample  28 A by submersion. Pressurization media  72 A forces liquid sample  74 A to filter through concave solid sample  28 A and fill central hole  29 A, whereupon it drains into hole  48 A. Valve  34 A can be opened to allow liquid sample  74 A to drain into receiver  38 A, allowing the measurement of the filtration value of concave solid sample  28 A and liquid sample  74 A under conditions of temperature and pressure. 
     Description 
     FIG.  4 —Detailed Close-Up of Solid Cone Bit  26 A and Conical Surface  27 A in FIG.  3   
       FIG. 4  is a detailed close-up of a solid cone bit  26 A pressed against conical surface  27 A on concave solid sample  28 A. Solid cone bit  26 A is shaped so that the angle of the cone corresponds exactly to the angle of conical surface  27 A, thus the upward force used to press the concave solid sample  28 A (F1) against the solid cone bit  26 A generates a normal force (F2) on conical surface  27 A. If the cone tip angle is α, then the relationship between (F1) and (F2) is:
 
 F 2= F 1/sin(½α)
 
When α is small, (F1) will produce a greatly-enhanced force (F2), requiring much less energy than would otherwise be necessary to produce a very high level of friction. This allows the solid cone bit  26 A and the concave solid sample  28 A to simulate down-hole conditions of pressure and friction which are much higher (and thus more analogous to realistic down-hole conditions in a well being drilled) than they actually are, eliminating the necessity of applying those actual levels of energy or friction.
 
     Description 
     FIG.  5 —Back Pressure Accumulator Assembly 
       FIG. 5  is a cross-section view of an a configuration in which the receiver  38  in  FIG. 1  is replaced with an accumulator assembly  88 B comprising a tube  36 B which connects to the bottom area of an accumulator  88 B and through which filtrate from sample  74  in  FIG. 1  is introduced into accumulator assembly  88 B. A sensor  86 B detects the movement of a piston  84 B as it rises and/or falls. A pressurization media source (in this illustration, nitrogen) is piped into the top area of accumulator assembly  88 B via a gas tube  82 B. Said nitrogen, in this figure, can provide back pressure for the operation of the lubricity tester. 
     Description 
     FIG.  6 —Inverted Rotor Assembly 
       FIG. 6  is a cross-section view of a lubricity tester  80 C with a cylindrical sample cup  20 C and a bearing holder  14 C. Sample cup  20 C is screwed onto bearing holder  14 C via a thread  16 C. A top shaft  100  passes through the center of bearing holder  14 C, and is rotationally supported by a bearing  70 C, a bearing  68 C, a bearing spacer  69 C, a snap ring  67 C, and a snap ring  71 C. An o-ring  66 C assures against leakage through thread  16 C. An o-ring  18 C assures against leakage around top shaft  100 . 
     A sample holder  56 C is screwed onto the lower end of top shaft  100  via a thread  22 C. A solid sample  28 C, which typically can be a porous rock or a solid, non-porous metal, is placed up inside sample holder  56 C and is secured to sample holder  56 C by a retainer  60 C, which is screwed onto sample holder  56 C via a thread  58 C. 
     A bottom shaft  46 C extends up through the bottom of sample cup  20 C. An o-ring  50 C assures against leakage around bottom shaft  46 C. A ring  26 C is attached at the top of bottom shaft  46 C via a thread  54 C. Sample cup  20 C is partially filled with a pressurization media  72 C and a liquid sample  74 C. Liquid sample  74 C submerges ring  26 C. Pressurization media  72 C is introduced through a pressurization port  12 C. Pressurization media  72 C is introduced through a pressurization port  12 C. 
     A loading device  42 C pushes bottom shaft  46 C upward so that ring  26 C presses against solid sample  28 C, and movement of bottom shaft  46 C is recorded by a displacement sensor  40 C. Temperature control is provided by a heater  64 C positioned radially outside sample cup  20 C. 
     Operation—FIG.  6 —Inverted Rotor Assembly 
     In  FIG. 6 , to assemble lubricity tester  80 C, place o-ring  18 C into bearing holder  14 C. Install bearing  68 C, bearing spacer  69 C, bearing  70 C, snap ring  67 C and snap ring  71 C onto top shaft  100 . Insert top shaft  10 C into bearing holder  14 C. Install o-ring  66 C onto bearing holder  14 C. Screw sample holder  56 C onto the bottom of top shaft  100  via thread  22 C. Install solid sample  28 C into sample holder  56 C and secure solid sample  28 C by screwing retainer  60 C into sample holder  56 C via thread  58 C. 
     Install o-ring  50 C onto bottom shaft  46 C, then insert bottom shaft  46 C into the bottom of sample cup  20 C. Screw ring  26 C onto bottom shaft  46 C via thread  54 C. 
     Pour liquid sample  74 C into sample cup  20 C. Screw sample cup  20 C onto bearing holder  14 C via thread  16 C. Loading device  42 C will move bottom shaft  46 C up, while recording the upward force applied on bottom shaft  46 C. This will also push ring  26 C upward against solid sample  28 C. Inject pressurization media  72 C through pressurization port  12 C. Adjust temperature as desired by activating heater  64 C. 
     As a motor  8 C top shaft  10 C rotating, sample holder  56 C and solid sample  28 C rotate and rub against ring  26 C, causing the surface of solid sample  28 C to wear away. As it does so, the power consumption and/or the torque value required to rotate shaft  10 C is also recorded. The lubricity between solid sample  28 C and ring  26 C is calculated from the torque on shaft  10 C and the upward force applied to bottom shaft  46 C. The displacement sensor  40 C records the changes as solid sample  28 C is abraded. 
     Ramifications 
     In  FIG. 1 , solid sample  28  can be cylindrical or rectangular in shape. 
     In  FIG. 1 , because torque applied on rotor  26  equals the reaction torque applied on solid sample  28  which is further transferred to bottom shaft  46 , torque measurement on bottom shaft  46  can be used to replace measurement of torque on top shaft  10 . 
     In  FIG. 1 , pressurization media  72  can be either gas or liquid as long as the pressure is controlled. 
     In  FIG. 1 , the rotor  26  might be shaped like a standard drill bit or other shaped drill bits, as would be used in an oil well drilling process. 
     In  FIG. 1 , lubricity tester  80  might be operated at any angle, providing that rotor  26  and solid sample  28  are constantly submerged in liquid sample  74 . This can be useful to simulate high-angle or horizontal drill conditions. 
     In  FIG. 1 , rotor  26  bottom can be shaped as a solid cylinder instead of a ring. 
     In  FIG. 2 , the circular drill bit  27  may be replaced by any other shaped drill bit, such as a conically threaded drill bit. 
     In  FIG. 3 , the solid cone bit  26 A might be shaped like a standard drill bit, as would be used in an oil well. 
     In  FIG. 3 , lubricity tester  80 A might be operated at any angle, providing that Solid cone bit  26 B and concave solid sample  28 A are constantly submerged in liquid sample  74 A. 
     In  FIG. 6 , because torque applied on sample holder  56 C and solid sample  28 C equals the reaction torque applied on ring  26 C which is further transferred to bottom shaft  46 C, torque measurement on bottom shaft  46 C can be used to replace measurement of torque on top shaft  100 . 
     In  FIG. 6 , lubricity tester  80 C might be operated at any angle, providing that ring  26 C and solid sample  28 C are constantly submerged in liquid sample  74 C. This can be useful to simulate high-angle or horizontal drill conditions. 
     In  FIG. 6 , a hole in top shaft  100  could be provided to collect and measure filtrate through solid sample  28 C. 
     In  FIG. 6 , ring  26 C could be replaced with a conical, circular, or other shaped drill bit. In  FIG. 6 , solid sample  28 C can be cylindrical or rectangular in shape. 
     CONCLUSION, AND SCOPE 
     Accordingly, the reader skilled in the art will see that this invention can be used to construct a high pressure vessel in which a solid and/or liquid sample can be tested under varying and controllable conditions of high pressure and high temperature conditions for lubricity and filtration capacity. In so doing, it satisfies an eminent drilling industry need. 
     Objects and Advantages 
     From the description above, a number of advantages of my lubricity tester become evident:
     a. Due to limited number of components, current invention is easy to operate and maintain.   b. The pressure rating of current invention will only be limited to the pressure rating of its pressure vessel, tubing and valves, which can be up to 60,000 psi.   c. Current invention can test both fluids and solids dynamically and statically under high pressure and high temperature.   d. Current invention can test fluids and solids for both lubricity and filtration values under high pressure and high temperature.   e. The shape of both the rotor and the solid sample may be adapted to more closely approximate the shape of specific industrial features, such as drill bits, or other abrading hardware.   

     Further objects and advantages of my invention will become apparent from a consideration of the drawings and ensuing description.