Patent Description:
When drilling oil and/or gas wells, oil-based drilling fluids are often used to cool the drill bit, remove rock chips, and control subsurface fluids. Various properties of this fluid can be measured to compute useful results. For example, the electrical stability of drilling fluid is a property that is typically measured using an electrical stability (ES) test. The ES test is typically a manual test that is performed by a mud engineer or an equivalent technician. Conventionally, when performing an ES test, a probe that includes circular flat electrodes of diameter <NUM>/<NUM> inch, spaced <NUM>/<NUM> inch between faces, is inserted into the drilling fluid. Drilling fluid, which contains nonaqueous fluid, water (or other polar liquid), clays, and other materials, fills the gap between the two electrodes of the test probe. Wires run from the probe to a signal generator and measurement meter, which ramps the voltage between the electrodes until components of the fluid align to form a short-circuiting bridge. When the short circuit occurs, the current between the electrodes immediately spikes. Specifically, an AC voltage of <NUM> is ramped at <NUM> V s-<NUM> until a peak current (approximately <NUM>µA) occurs. At this stage, the peak voltage, known as the breakdown voltage (VBD) is captured by the meter. <NUM>µA is the current at which the breakdown voltage occurs for the above-described geometry of the probe. The breakdown voltage is the voltage at which the drilling fluid's electrical properties become electric field-dependent and is the voltage at which the electrical conductivity of the drilling fluid becomes non-ohmic. Thus, the breakdown voltage is related to the emulsion stability and is then used to compute the emulsion stability and other properties of the drilling fluid.

Typically, to measure the electrical stability of drilling fluid using the above manual probe method, the drilling fluid and associated fluid is kept static, as movement and shifts in the fluids of the drilling fluid may cause the measurements taken by the electrodes and recorded by the meter to be skewed. In addition, when using the manual probe method described above, the electrodes and the gap between electrodes of the probe are manually cleaned after each measurement sampling.

In addition to measuring electrical stability, drilling rig operators may perform tests to determine viscosity. Typically, such measurements were performed with instruments such as a Marsh funnel viscometer. Marsh funnels are manually operated measurement devices that provide a drilling operator a general idea as to the viscosity of a particular fluid. In use, the funnel is held vertically and the end tube closed by covering the outlet with a finger. Fluid to be measured is then poured into the funnel until the fluid reaches a line indicating about <NUM> liters. To take the measurement, the finger is removed from the outlet and a stopclock is started. The fluid exits the funnel and the time to remove one quart of fluid from the funnel is recorded. With a known volume and a discharge time, the viscosity may be calculated.

While such measurement techniques give operators a general idea as to the viscosity, due to the manual implementation, the results may not always be accurate. Additionally, the viscosity of the fluid downhole is not truly known, because the fluid cannot be heated or measured under pressure.

In addition to electrical stability and viscosity, the gel strength of the fluid can also be determined. Gel strength is the measure of a fluid's ability to hold particles in suspension, and the gel strength is measure using a concentric cylinder viscometer. Gel strength is also measured manually and the results analyzed when adjusting the properties of the drilling fluid.

Accordingly, there exists a need for an automated method for measuring the electrical stability, viscosity, and/or gel strength of drilling fluid. Additionally, there exists a need for improved methods for sampling drilling fluid for appropriate measurements and cleaning of the electrodes of the probe used to measure the breakdown voltage of the drilling fluid. <CIT> describes a fluid testing apparatus. Similar viscosity measurement apparatuses can also be found in <CIT>, <CIT> and <CIT>.

The present invention resides in an automated electrical stability meter and a computer-assisted method for controlling an automatic drilling fluid property analyzer as defined in the appended claims.

Other aspects and advantages of the invention will be apparent from the following description and the appended claims.

In one aspect, embodiments disclosed herein relate to an automated meter to measure emulsion stability and rheological properties of drilling and completion fluids. More specifically, embodiments disclosed herein relate to autonomous analysis of drilling and completion fluids that may be performed or analyzed remote from the rig or testing site.

Embodiments disclosed herein relate to a method and apparatus for automating the measurement of properties of invert emulsion oil-based or synthetic-based fluids (i.e., drilling fluids and/or completion fluids) and water based fluids. Although the disclosure herein may reference drilling fluid, one of ordinary skill in the art will appreciate that other types of fluids (e.g., completion fluids) may also be tested with the method and apparatus disclosed herein.

Referring to <FIG>, a general schematic of an automated fluid property analyzer <NUM> in accordance with embodiments disclosed herein is shown. The automated fluid property analyzer <NUM> is placed in line with an active fluid system and configured to obtain a sample of fluid from the system for analyzing. As shown, the automated fluid property analyzer <NUM> includes a sample cell <NUM>, a valve block <NUM>, and a pump <NUM>. Although the valve block <NUM> is illustrated as a single unit, one of ordinary skill in the art will appreciate that valve block <NUM> may include one or more valves arranged as necessary to provide fluid flow in and out of the sample cell <NUM>. An electronic control module <NUM> is operatively connected to the sample cell <NUM>, valve block <NUM>, and pump <NUM>, as designated by the phantom lines. Generally, a fluid is pumped by pump <NUM> through inlet <NUM> of valve block <NUM> into sample cell <NUM>. The pump <NUM> may be, for example, a pneumatic pump or a positive displacement pump. The fluid may be tested in sample cell <NUM> and/or cycled through the sample cell and out through outlet <NUM> in valve block <NUM>. The valve block <NUM> may also include a cleaning fluid inlet <NUM> through which a cleaning fluid may be pumped into the sample cell <NUM> for cleaning the sample cell <NUM> between tests of the fluid. One of ordinary skill in the art will appreciate that various fluids may be used for cleaning the sample cell <NUM>. For example, the cleaning fluid may be mineral oil, diesel, or water and may include various chemical additives, such as surfactants and/or acid.

As discussed in greater detail below, the sample cell <NUM> may include a housing (not shown) configured to contain a desired volume of fluid for sampling and analyzing. One of ordinary skill in the art will appreciate that the volume of the housing may vary based on the type of fluid to be sampled, size constraints of the location at which the sampling is to be performed, and the types of analysis to be performed. In some embodiments, the volume of the sample cell housing may be in a range between <NUM> and <NUM>. In some embodiments, the volume of the sample cell is <NUM>. The sample cell <NUM> may include devices or components configured to determine at least one of an electrical stability, a gel strength, and a viscosity of the fluid sampled, as discussed below. For example, in one embodiment, the sample cell may include an automated electrical stability meter, an automated viscometer, or a combination of both.

The electronic control module <NUM> includes electronics configured to send and/or receive signals between the components of the sample cell <NUM>, the valve block <NUM>, and pump <NUM> to automate the sampling and analysis process. The electronic control module <NUM> may send periodic signals to the valve block <NUM> and a component for determining an electrical stability of a sample fluid in the sample cell <NUM>, thereby initializing a measurement reading. The electronic control module <NUM> may be configured to control the timing between measurement readings/data acquisition. Those skilled in the art will appreciate that the frequency of measurement readings may be determined by factors other than timing. For example, drilling fluid may be sampled and measured based on the quantity of drilling fluid that is driven through the sample cell <NUM>. Alternatively, drilling fluid may be sampled and measured on-demand and/or in real-time.

In one or more embodiments, configuration files stored on a USB flash drive (not shown), or other type of computer readable medium or storage device, are provided to the electronic control module <NUM> via a USB connector (not shown). Those skilled in the art will appreciate that other types of connectors and storage devices may also be employed. For example, an SD card and corresponding SD connector may be used to store and load configuration files. Alternatively, a hard drive, floppy disk drive, internal memory, or a CD may also be used. The configuration files may include probe waveform definitions, calibration data, and automated and manual process definitions for the electronic control module <NUM>.

Referring now to <FIG>, an automated electrical stability meter <NUM> for measuring electrical stability of a sample of fluid is shown in accordance with embodiments disclosed herein. The automated electrical stability meter <NUM> includes a housing (not shown) configured to contain a volume of fluid to be analyzed. The sample fluid enters the housing through an inlet <NUM> and exits the housing through an outlet <NUM>. A pump (not shown) is configured to pump the sample fluid in and out of the housing when signaled from the electronic control module (not shown).

A probe assembly <NUM> is disposed in the housing (not shown) and operatively coupled to the electronic control module (not shown). The probe assembly <NUM> includes an electrode probe <NUM> for measuring the electrical stability and other properties of the drilling fluid. The electrode probe <NUM> is a fork-shaped probe with two electrodes <NUM> on each tong-like piece. Between the two electrodes <NUM> is a probe gap <NUM>. When fluid fills the volume of the housing, the fluid is directed through the probe gap <NUM> of the probe assembly <NUM>. A voltage is applied across the probe gap to determine an electric stability of the drilling fluid based at least in part on the applied voltage. A series of measurements, i.e., a testing sequence, may be taken with the same fluid sample in the housing.

the electrical stability meter <NUM> includes a cleaning mechanism <NUM> configured to clean the probe gap <NUM> between the two electrodes <NUM>. The cleaning mechanism <NUM> is configured to remove any residue from the surface of the electrodes <NUM> or stuck in the probe gap <NUM> to ensure proper test results of subsequent fluid samples. As shown in <FIG>, cleaning mechanism <NUM> may include a rotating disc <NUM> coupled to a shaft <NUM>. The shaft <NUM> is coupled to a motor <NUM>. Motor <NUM> is coupled to an outer surface of the housing (not shown), and the shaft <NUM> extends into the housing proximate the probe assembly <NUM>. When the motor <NUM> receives a signal from the electronic control module (not shown), the motor <NUM> rotates the shaft <NUM> and, therefore, the disc <NUM>. The width of the disc <NUM> is approximately equal to the width of the probe gap <NUM> (i.e., the distance between the two electrodes <NUM>). Therefore, as the disc <NUM> is rotated between the electrodes <NUM>, the disc <NUM> removes any remaining residue from the probe gap <NUM> and the electrodes <NUM>. The electronic control module (not shown) may operate the cleaning mechanism <NUM> between sampling and testing sequences. Cleaning of the probe assembly <NUM> may be performed at predetermined time intervals or may be individually initiated by the electronic control module (not shown).

The disc <NUM> may be formed from any material known in the art capable of cleaning a surface. In one embodiment, the disc <NUM> is formed from a flexible material so as to prevent damage to the electrodes <NUM>. Disc <NUM> may be formed from polyethylene, for example ultra high molecular weight polyethylene (UHMW), or polytetrafluoroethylene (PTFE). As shown, the disc <NUM> includes a cutout or opening <NUM> extending through the width of the disc <NUM>. Once cleaning of the probe assembly <NUM> is completed, rotation of the disc <NUM> is stopped such that the opening <NUM> is in alignment with the probe gap <NUM>. Thus, analysis of a sample of fluid is to be performed, the opening <NUM> of the disc <NUM> is positioned between the electrodes <NUM> in the probe gap <NUM> so as to provide a maximum volume of sample fluid between the electrodes <NUM> for measurement of the electrical properties of the fluid.

A position indicator (not shown) may be coupled to the motor <NUM> or the rotating disc <NUM>. The position indicator (not shown) is operatively coupled to the electronic control module (not shown) and configured to send a signal representative of the location of the rotating disc <NUM> and the opening <NUM>. The signal representative of the location of the rotating disc <NUM> may be compared to predetermined values for locations of the disc <NUM> with respect to the probe assembly <NUM> for sampling and testing sequences or cleaning sequences to ensure that the opening <NUM> is properly aligned with the probe assembly <NUM>. While the cleaning mechanism <NUM> as described may include a rotating disc <NUM>, one of ordinary skill in the art will appreciate that other cleaning mechanisms may be used without departing from the scope of embodiments disclosed herein. For example, a wiper blade may be rotated into and out of the probe gap <NUM>, an actuated squeegee may wipe the surfaces of the electrodes <NUM>, or jets may be installed proximate the electrodes to blast residue off of the electrodes <NUM> with fluid, such as water, base oil, or air.

The automated electrical stability meter <NUM> includes an agitator (not shown). In one embodiment, the agitator may include a one or more turbine blades coupled to the cleaning mechanism <NUM>. For example, one or more turbine blades may be coupled to the shaft <NUM> and/or the rotating disc <NUM>. Thus, as the rotating disc <NUM> is operated, the turbine blades (not shown) of the agitator (not shown) also rotate and mix the fluid contained within the housing. Rotation of the agitator (not shown) stirs or mixes the fluid contained in the housing and reduces or prevents settling of particulates or separation of liquids in the fluid. The electronic control module (not shown) may operate the agitator (not shown) between sampling and testing sequences. Agitation of the fluid in the housing may be performed at predetermined time intervals or may be individually initiated by the electronic control module (not shown).

A thermal jacket (not shown) is disposed around the housing (not shown) of the automated electrical stability meter <NUM>. The thermal jacket is configured to heat the sampled fluid contained within the housing (not shown). In one embodiment, the thermal jacket includes an electrical circuit configured to supply an alternating current to heat the fluid contained in the housing (not shown). In another embodiment, the thermal jacked includes an electrical circuit configured to supply a direct current to heat the fluid contained in the housing (not shown). The electronic control module (not shown) may be used to control the electrical circuit in the thermal jacket and, therefore, heating of the sample fluid.

To cool the fluid contained in the housing, a water jacket may be disposed around the housing (not shown) of the automated electrical stability meter <NUM>. For example, cooling loop <NUM> (<FIG>) may be run along a portion of the housing or around the circumference of the housing (not shown). In this embodiment, a water supply line <NUM> (<FIG>) may be connected to a loop of tubing encircling or placed adjacent the housing (not shown) of the automated electrical stability meter <NUM>. A valve may be actuated by, for example, the electronic control module to provide a flow of fluid having a temperature less than the sample fluid to the cooling loop. Heat from the sample fluid is transferred to fluid flowing through the cooling loop <NUM> (<FIG>), thereby cooling the sample fluid. The cooling fluid may be, for example, water, sea water, or any other fluid known in the art. The cooling loop <NUM> may allow for a more rapid cooling of the sample fluid, thereby decreasing the time between tests. As the time between tests may be decreased, more frequent samples of the fluid may be obtained, thereby informing a drilling engineer as to changes in electrical stability and gel strength.

In other embodiments, a Peltier device (not shown) may be coupled to the housing and used to cool and/or heat the fluid contained in the housing. A Peltier device uses the Peltier effect to create heat flux across the device. The Peltier device may be coupled to a DC voltage generator. The resultant temperature of the sample fluid may be determined by the amount of current provided to the Peltier device.

A temperature sensor (not shown) may be disposed in the housing of the automated electrical stability meter <NUM>. The temperature sensor is operatively coupled to the electronic control module (not shown) and is configured to sense and transmit data representative of the temperature of the sample fluid. The electronic control module may be configured to continuously monitor the temperature of the sample fluid, to monitor the temperature of the sample fluid at timed intervals, to monitor the temperature of the sample fluid before and/or after each testing sequence, or to monitor the temperature of the sample fluid at manually initiated times. Based on readings of the temperature sensor (not shown) and a predetermined desired temperature input value, the electronic control module (not shown) may initiate heating or cooling of the sample fluid, as discussed above.

Referring to <FIG>, a top view of the electrical stability meter <NUM> of <FIG>, according to embodiments of the present disclosure is shown. In this embodiment, electrical stability meter <NUM> includes a probe assembly <NUM> disposed in a housing <NUM>. An electrode probe <NUM> is configured to measure the electrical stability, as well as other properties of a sample drilling fluid. Between electrodes (not shown) of electrode probe <NUM>, a probe gap <NUM> is formed. During operation, a sample drilling fluid is provided in the probe gap <NUM>, a voltage is applied across the probe gap <NUM> such that an electrical stability of the sample drilling fluid may be determined. A cleaning mechanism <NUM>, such as a wiper blade, is configured to rotate into probe gap <NUM>, thereby allowing the probe gap <NUM> to be cleaned between testing cycles.

Electrical stability meter <NUM> also includes an agitator <NUM> that is configured to rotate. Agitator <NUM> includes one or more blades <NUM> that may be rotated in order to mix fluid within the housing <NUM>. The mixing of fluid within housing <NUM> prevent solids particles from settling out or otherwise separating from the mixing during and between testing cycles. In certain embodiments, housing <NUM> may also includes a heating/cooling jacket <NUM>. The heating/cooling jacket <NUM> may thereby heat and subsequently cool sample drilling fluids, thereby allowing the fluid to be tested according to downhole conditions. Additionally, the jacket <NUM> may allow the sample drilling fluid to be cooled more rapidly between test cycles, thereby decreasing the time between tests.

Referring now to <FIG>, a process and instrumentation diagram of the closed system automated electrical stability meter <NUM> is shown. As shown, an automated electrical stability meter <NUM> is placed in line with an active fluid system <NUM>. A plurality of valves <NUM> control flow of fluids in and out of the automated electrical stability meter <NUM>. In one embodiment, at least one valve <NUM> is a solenoid valve, while in other embodiments, valve <NUM> may include check valves or combinations of solenoid and check valves. In certain embodiments, rather than a solenoid valve, other types of actuated valves may be used. In certain embodiments, solenoid valves having large passageways are coupled to the inlet <NUM> and outlet <NUM> of the automated electrical stability meter <NUM>. Such solenoid valves may be used to prevent a build up of residue, particles, or debris from settling out of the fluid transported therethrough and blocking the valve. Such valves are commercially available from ASCO® (Florham Park, NJ). The solenoid valves may be also be positioned so as to prevent material from settling into areas of the valve that may prevent proper actuation of the valve.

Referring briefly to <FIG>, a specific type of valve <NUM> according to embodiments of the present disclosure is shown. In <FIG>, a check valve <NUM> is shown. The check valve <NUM> includes a plunger <NUM>, a valve body <NUM>, and a plunger assembly <NUM> including an elastomer material <NUM>. During a fill stage of the testing (<FIG>), during low pressure conditions, the fluid is flowing along path A, thereby moving the plunger <NUM> into an open position and allowing fluid to flow into the electrical stability meter. During a high pressure condition, such as during a back flow, the fluid is flowing in direction B (of <FIG>), causing the plunger <NUM> to close and seal check valve <NUM>. Such a one-way check valve may be less prone to failure from liquids or slurries that are highly viscous or contain particulate matter. Referring briefly to <FIG>, an exploded view of check valve <NUM> is shown. As illustrated, check valve <NUM> includes a valve body <NUM>, a plunder assembly <NUM> having an elastomer material <NUM>, and a plunger guide <NUM>. The elastomer material <NUM> is configured to seal against sealing surface <NUM> of valve body <NUM>, and is configured to remain constrained within plunger guide <NUM>. Those of ordinary skill in the art will appreciate that in certain embodiments, a check valve <NUM> may be used along or in combination with other types of valves, such as the solenoid valves described above.

Referring back to <FIG>, s shown, a valve <NUM> is actuated on a fluid inlet line <NUM> to sample fluid from the active fluid system <NUM>. The electronic control module <NUM> includes, for example, a programmable logic controller <NUM> or a micro processor and a voltage generator <NUM>. The electronic control module <NUM> is configured to send a signal to at least one of the valves <NUM> to open or close. The sample fluid is directed through the inlet <NUM> of the automated electrical stability meter <NUM>. A temperature sensor <NUM> operatively coupled to the electronic control module <NUM> is disposed in the housing <NUM> of the automated electrical stability meter <NUM>. If the temperature sensed by the temperature sensor <NUM> is above or below a predetermined temperature value, the electronic control module <NUM> sends a signal to the thermal jacket <NUM> or the cooling loop <NUM> to heat or cool, respectively, the sample fluid.

Specifically, if the temperature of the sample fluid needs to be raised, the electronic control module <NUM> sends a signal to generate a current in the thermal jacket <NUM>. The electrical current in the thermal jacket heats the sample fluid until the predetermined temperature is reached. Similarly, if the temperature of the sample fluid needs to be lowered, the electronic control module <NUM> sends a signal to a valve <NUM> disposed on the cooling loop line <NUM> to circulate water (or other fluids) from the water supply line <NUM> around the housing <NUM> of the automated electrical stability meter <NUM>, thereby cooling the sample fluid. The temperature sensor <NUM> may continuously monitor the temperature of the fluid during heating or cooling periods of the sample fluid.

A pressure sensor <NUM> may be operatively coupled to the housing <NUM> and to the electronic control module <NUM>. If the pressure sensed by the pressure sensor <NUM> in the closed system automated electrical stability meter <NUM> is below or above a predetermined pressure value, the electronic control module <NUM> signals the valve <NUM> on an air supply line <NUM> to open or close to increase or decrease, respectively, the pressure inside the housing <NUM>.

The probe assembly <NUM> disposed in the automated electrical stability meter <NUM> is actuated by the electronic control module <NUM> and a voltage is supplied by the voltage generator <NUM> to the probe electrodes (not independently illustrated). The voltage generator may supply a ramped voltage to the probe assembly <NUM>, as set by control circuitry in the electronic control module <NUM>. In one embodiment, the voltage generator may supply <NUM> to <NUM>,<NUM> volts to the probe assembly <NUM>.

The standard API electrical stability test specifies a <NUM> sinusoidal AC signal that ramps from <NUM>-<NUM> volts at <NUM> volts per second. The procedure (i.e., software) stored in a configuration file is used to determine when to drive a particular waveform signal to the probe assembly <NUM>. In one or more embodiments, the waveform(s) are stored as separate files and may not be part of the configuration file. The API standard ES reading is the peak voltage at which the current reaches <NUM>µA. However, the configuration file may also provide the ECM with signals that are based on a non-linear voltage ramp and/or other types of ramp rates. Those skilled in the art will appreciate that the specifications of the electrical stability test may be changed by programming different waveforms onto the configured file that is fed to the electronic control module. Thus, the threshold current may be a value higher or lower than <NUM>µA.

The electronic control module <NUM> controls actuation of the cleaning mechanism <NUM>. At predetermined intervals or as needed, the motor <NUM> is actuated by the electronic control module <NUM>, thereby rotating the wiper or rotating disc (not shown) into the probe gap (not shown) of the probe assembly <NUM>. The position indicator (not shown) sends signals back to the electronic control module <NUM> indicating the rotational position of the disc or the relative position of the cleaning mechanism <NUM> with respect to the probe gap. The motor <NUM> may also be signaled by the electronic control module <NUM> to actuate the agitator (not shown). The agitator may be run to ensure thorough mixing of the fluid and reduce and/or prevent settling of material within the housing.

After the testing sequence is completed, the electronic control module <NUM> signals the outlet <NUM> to open and initiate the pump <NUM> to pull the sample fluid from the housing <NUM> of the automated electrical stability meter <NUM> and return the sample fluid to the active fluid system <NUM>. An additional sampling and testing sequence may then be initiated or a cleaning sequence may be initiated. To implement a cleaning sequence, electronic control module <NUM> sends a signal to the cleaning mechanism <NUM>, as discussed above, and sends a signal to a valve <NUM> on a cleaning fluid line <NUM> to open the valve <NUM> and transfer cleaning fluid to the housing <NUM>. The cleaning mechanism <NUM> is operated within the housing <NUM> while the cleaning fluid is flushed through the housing. The agitator (not shown) may also be run to enhance cleaning of the housing <NUM> and probe assembly <NUM>. Cleaning fluid may be drained through the outlet <NUM> and discarded.

Referring to <FIG> and <FIG> together, the automated electrical stability meter <NUM>, including the housing <NUM>, electronic control module <NUM>, valves <NUM>, and various supply lines and drain lines may be disposed within in a shell housing <NUM>. The shell housing <NUM> encloses all of the main components of the automated electrical stability meter <NUM>. The shell housing <NUM> may include a plurality of ports or connections for connecting fluid lines, for example, the active fluid system line, water lines, drain lines, etc. to the housing <NUM> of the automated electrical stability meter <NUM>. A display <NUM> mounted to the shell housing <NUM> is configured to display information representative of the results of signals sent and received by the electronic control module <NUM>. For example, the display <NUM> may display electrical stability of the sample fluid, temperature of the sample fluid, pressure within the housing <NUM>, etc..

Referring now to <FIG>, an automated viscometer <NUM> for measuring gel strength and/or viscosity of a sample of fluid is shown in accordance with embodiments disclosed herein. The automated electrical stability meter <NUM> includes a housing (not shown) configured to contain a volume of fluid to be analyzed. Similar to the automated electrical stability meter discussed above, the sample fluid enters the housing through an inlet (not shown) and exits the housing through an outlet (not shown). A pump (not shown) is configured to pump the sample fluid in and out of the housing when signaled from an electronic control module (not shown).

The automated viscometer <NUM> includes a viscometer sleeve <NUM> disposed in the housing (not shown), a bob <NUM> disposed in the sleeve <NUM>, a motor <NUM> operatively coupled to at least one of the viscometer sleeve <NUM> and the bob <NUM>, and a torque measuring device <NUM> operatively coupled to the viscometer sleeve <NUM> and/or the bob <NUM>. In the embodiment shown, the bob <NUM> is suspended by a torsion wire <NUM> (<FIG>) from the torque measuring device <NUM> and the sleeve <NUM> is rotated by the motor <NUM>. An annulus <NUM> is formed between the viscometer sleeve <NUM> and the bob <NUM>. After a sample fluid is transferred from the active drilling fluid system into the housing, the fluid is directed to the annulus <NUM> between the viscometer sleeve <NUM> and the bob <NUM>. Depending on the configuration of the automated viscometer <NUM>, either the viscometer sleeve <NUM> or bob <NUM> is rotated at a specific speed by the motor <NUM>. The specific speed determines the shear rate of the fluid inside the annulus <NUM>. The torque exerted on bob <NUM> or viscometer sleeve <NUM>, as determined by the torque measuring device <NUM>, is recorded, and the data is either stored or sent to a remote computer system for processing, as described below. For example, the torque measuring device <NUM> may measure the amount of twist of the torsion wire <NUM> caused by the drag rotation of the bob <NUM>. Said another way, torque measuring device <NUM> may measure the torque caused by movement of the torsion wire <NUM>. Based on the torque detected, the viscosity and gel strength of the fluid may be determined.

As described in detail above with respect to the automated electrical stability meter <NUM> (<FIG>), the electronic control module <NUM> (<FIG>) may similarly control the automated viscometer <NUM>. The electronic control module <NUM> (<FIG>) may send signals to solenoid valves (not shown) to open and close flow lines for directing a sample fluid from an active fluid system into the housing (not shown) of the automated viscometer <NUM>. Once the housing is filled with a sample fluid, the electronic control module <NUM> (<FIG>) may send a signal to the motor <NUM> to run/spin the bob <NUM> of sleeve <NUM>. The torque measuring device <NUM> may determine an applied torque based on specified speed of rotation and the drag rotation the sample fluid in the annulus <NUM> creates on the non-rotating bob <NUM> or sleeve <NUM>. The data collected by the torque measuring device <NUM> may be sent to the electronic control module <NUM> (<FIG>) for further processing. Once the sample fluid has completed the testing sequence, the electronic control module <NUM> sends a signal to a valve (not shown) and a pump (not shown) to transfer the sample fluid back to the active fluid system (not shown).

In one embodiment, a magnetic coupling (not shown) may be disposed between the bob <NUM> and the torque measuring device <NUM>. Because the torque measured by the torque measuring device <NUM> is typically very low, seal drag between the bob <NUM> and the torque measuring device <NUM> should be reduced or eliminated. The magnetic coupling (not shown) reduces or eliminates seal drag between the bob <NUM> and the torque measuring device <NUM> for more accurate measurement of the torque on the bob <NUM>.

Similar to the automated electrical stability meter <NUM> (<FIG>), temperature and pressure sensors (not shown) may be disposed within the housing of the automated viscometer <NUM> to determine and monitor the temperature and pressure of the sample fluid contained therein. Additionally, the electronic control module <NUM> (<FIG>) may actuate a thermal jacket, a cooling loop, or initiating pressurization or depressurization of the housing based on a comparison of the determined temperature and pressure and predetermined temperature and pressure values. The closed system automated viscometer <NUM> provides maintenance of the temperature and pressure of the fluid within the housing, which may improve the accuracy of the rheological properties of the fluid measured.

Referring now to <FIG> and <FIG>, an automatic drilling fluid property analyzer <NUM> in accordance with embodiments disclosed herein is shown. The automatic drilling fluid property analyzer <NUM> includes an automated electrical stability meter <NUM> and an automated viscometer <NUM>. As shown, the automatic drilling fluid analyzer <NUM> includes a housing <NUM> having an inlet <NUM> and an outlet <NUM>. At least one solenoid valve (not shown) is disposed proximate at least one of the inlet <NUM> and the outlet <NUM> and configured to open and close to provide a sample of fluid from an active fluid system into the housing <NUM>.

A temperature sensor (not shown) may be disposed inside the housing <NUM> and configured to determine a temperature of the fluid contained therein. A thermal jacket <NUM> encases at least a portion of the housing <NUM> and is configured to heat the sample fluid if the temperature sensor senses a temperature below a predetermined value or it otherwise actuated by the electronic control module <NUM> (<FIG>). A cooling loop (not shown) or a water jacket (not shown) may also enclose at least a portion of the housing <NUM>. The cooling loop is configured to cool the sample fluid in the housing <NUM> if the temperature sensor senses a temperature above a predetermined value.

A pressure sensor (not shown) may be operatively coupled to the housing <NUM> and configured to determine a pressure inside the housing. If the pressure sensor senses a pressure below a predetermined pressure value, air or fluid may be added to the housing <NUM> through a valve-controlled flow line (not shown) to increase the pressure. If the pressure sensor senses a pressure above the predetermined pressure value, a valve may be opened to relieve the pressure within the housing <NUM>.

A probe assembly <NUM> is coupled to the housing <NUM> for measuring electrical stability of the sample fluid in the housing <NUM>. The probe assembly <NUM> includes an electrode probe <NUM> having two electrodes (not shown) extending into a volume of the housing <NUM>. A cleaning mechanism <NUM> is disposed in the housing <NUM> and configured to move into engagement with a probe gap (not shown) between the electrodes of the electrode probe <NUM>. In the embodiment shown, the cleaning mechanism <NUM> includes a rotating disc <NUM> coupled to a shaft <NUM> rotated by a motor <NUM>. Motor <NUM> is coupled to an outer surface of housing <NUM> and is configured to rotate the cleaning mechanism <NUM> and/or an agitator (not shown). A position indicator (not shown) may be coupled to the motor <NUM> or the cleaning mechanism <NUM> and configured to detect a relative position of the cleaning mechanism <NUM> with respect to the probe assembly <NUM>.

The viscometer sleeve <NUM> and bob <NUM> of the automated viscometer <NUM> are disposed in the housing <NUM>. As discussed above with respect to the automated viscometer <NUM>, a motor <NUM> is operatively coupled to at least one of the viscometer sleeve <NUM> and the bob <NUM>, and a torque measuring device <NUM> is operatively coupled to the viscometer sleeve <NUM> and/or the bob <NUM>. In the embodiment shown, the bob <NUM> is suspended by a torsion wire <NUM> from the torque measuring device <NUM> and the sleeve <NUM> is rotated by the motor <NUM>. An annulus <NUM> is formed between the viscometer sleeve <NUM> and the bob <NUM>. Depending on the configuration, either the viscometer sleeve <NUM> or bob <NUM> is rotated at a specific speed by the motor <NUM>. The specific speed determines the shear rate of the fluid inside the annulus <NUM>. The torque exerted on bob <NUM> or viscometer sleeve <NUM>, as determined by the torque measuring device <NUM>, is recorded, and the data is either stored or sent to a remote computer system for processing, as described below. For example, the torque measuring device <NUM> may measure the amount of twist of the torsion wire <NUM> caused by the drag rotation of the bob <NUM>. Based on the torque detected, the viscosity and gel strength of the fluid may be determined.

The automatic drilling fluid property analyzer <NUM> may be disposed in a shell housing <NUM>, as shown in <FIG> and <FIG>. The shell housing <NUM> may be divided into two segments, a first area <NUM> in which the sample housing, automated electrical stability meter <NUM>, and automated viscometer <NUM> components are housed, and a second area <NUM> in which an electronic control module <NUM> is housed. As shown, a housing <NUM> may be fitted over the motor <NUM> and torque sensing device <NUM>. Details of the electronics of the electronic control module <NUM> are discussed in more detail below. Electrical conduits and wiring <NUM> may be run between the first area <NUM> and the second area <NUM> for electrically connecting various components of the analyzer <NUM>, for example, motor <NUM>, motor <NUM>, torque measuring device <NUM>, valves <NUM>, etc., to the electronic control module <NUM>. Shell housing <NUM> may include one or more vents and/or fans <NUM> configured to prevent the analyzer components and electronics from overheating. The valves, <NUM> may include check valves, as discussed above, which may be disposed in a manifold <NUM>. The manifold <NUM> may thus include various valves <NUM>, inlets and outlets, thereby controlling the flow of fluid into and out of the analyzer <NUM>.

As shown, the automatic drilling fluid property analyzer <NUM> also includes a pump <NUM> for pumping sample fluid into and out of the housing <NUM> of the analyzer <NUM> from an active fluid system. One or more solenoid valves <NUM> are disposed within the shell housing <NUM> and fluidly connected to the housing <NUM>. The solenoid valves <NUM> are actuated to allow a sample fluid to fill housing <NUM> for testing.

<FIG> shows a rear view of the shell housing <NUM> of the automatic drilling fluid property analyzer <NUM> having a plurality of plumbing connections for connecting outside fluid lines to various components of the analyzer <NUM>. As shown, the shell housing <NUM> may include connections for a water line in <NUM>, an air line in <NUM>, a mud line in <NUM>, and a cleaning fluid line in <NUM>. Additionally, connections for waste return <NUM> and water return <NUM> may also be provided.

Referring generally to <FIG>, in some embodiments, automatic drilling fluid property analyzer <NUM> may also include an alarm system configured to send a signal when an alarm event has occurred. The alarm system may include a plurality of sensors disposed in or proximate various components of the automatic drilling fluid property analyzer <NUM> and an alarm. For example, a temperature sensor may be disposed in the shell housing <NUM> and send a signal to the electronic control module <NUM> when a temperature inside the shell housing exceeds a predetermined maximum value. The electronic control module will then actuate the alarm. The alarm may be a bell, buzzer, electronic sound, or any other alarm known in the art. Additionally, the display <NUM> of the analyzer may display a message or indicate an alarm event has occurred. The display <NUM> may specify the type of alarm event. The display may, for example, note that the analyzer has overheated. Examples of alarm events may include a plugged valve, an open door to the shell housing, a low fluid level in the housing, disconnection of a flow line. The alarm system may include various types of sensors, for example, contact sensors, pressure sensors, temperature sensors, position sensors, etc..

In other embodiments of the drilling fluid analyzer, an x-ray spectrometer may be used to determine the content of a sample drilling fluid. For example, a sample may be excited by high energy x-rays or gamma rays, thereby causing the emission of secondary, fluorescent, x-rays. The secondary x-rays may then be analyzed to determine the chemical composition of the sample drilling fluid. The results of the testing may then be transferred to local storage or to a remote facility for processing. Those of ordinary skill in the art will appreciate that other meters may also be used to further analyze drilling fluid samples.

Referring to <FIG>, a schematic representation of a fluid analyzer having an x-ray spectrometer ("XRF") <NUM> according to embodiments of the present disclosure is shown. In this embodiment, a flow of fluid is directed from an active drilling system flow line <NUM> through one or more valves <NUM> and into a test chamber <NUM>. Inside test chamber <NUM>, a slide (<NUM> of <FIG>) is disposed and configured to move in one or more directions, thereby allowing a sample of drilling fluid to be procured from the active fluid system. One or more motors <NUM>, <NUM>, and <NUM> may be used to control the orientation of the slide or test chamber <NUM>. As illustrated, motor <NUM> is configured to move slide laterally in test chamber <NUM>. However, in other embodiments, motor <NUM> may be used to move slide in more than one direction. The fluid analyzer also includes a helium tank <NUM> in fluid communication with XRF <NUM>, thereby allowing helium to be used during the analysis. In order to control the flow of helium from helium tank <NUM> to XRF <NUM>, a solenoid valve <NUM> may be operatively controlled by a micro processor <NUM> or PLC.

The fluid analyzer may also include a cleaning fluid tank <NUM> in fluid communication with test chamber <NUM>. During a cleaning cycle, a fluid, such as a base oil, water, or other fluid containing chemicals such as surfactants may be transferred from the cleaning fluid tank <NUM> to the test chamber <NUM>. The flow of the cleaning fluid may be controlled by a valve, such as solenoid valve <NUM>. In addition to cleaning fluid, fluid analyzer may include an air system <NUM> configured to supply air to test chamber <NUM> or another component of the fluid analyzer. The flow of air may also be controlled with a valve, such as a solenoid valve <NUM>. After a test is complete, the sample fluid may be drained from test chamber <NUM> through waste drain <NUM> and back into the active drilling system flow line <NUM>. The sample fluid evacuation may be facilitated though use of a pump <NUM>, air from air system <NUM>, or pushed out of test chamber <NUM> as new fluid is drawn into test chamber <NUM>. The fluid analyzer may also include various sensors, such as pressure sensor <NUM>, temperature sensors (not shown), or other various sensors for determining the position of the slide within test chamber <NUM> or a property of the fluid. In certain embodiments, the fluid analyzer may also include various check valves, such as those discussed above, as well are various temperature control apparatuses, such as heating/cooking jackets.

To control fluid analyzer, the system includes micro processor <NUM> and a local memory storage <NUM>, such as a hard disc drive, flash, or other type of memory known in the art. Data may be displayed and the fluid analyzer may be controlled through local display <NUM>. Additionally, a device for allowing a connection to a network, such as a modem <NUM>, may be used to allow the fluid analyzer to communicate data as well as receive control signals remotely. The remote control aspect of the present disclosure will be explained in detail below.

Referring now to <FIG>, cross-sectional views of the test chamber and XRF <NUM> during fill, intermediate, and test positions, respectively, according to embodiments of the present disclosure are shown. In the fill position (<FIG>), the slide <NUM> is in a position to allow fluid to be injected through an injection port <NUM> into a sample cavity <NUM>. In this embodiment, sample cavity includes approximately a <NUM> opening that allows fluid to flow into the cavity <NUM>. Those of ordinary skill in the art will appreciate that in other embodiments, sample cavity <NUM> may include openings of different size and/or geometry. One or more of motors (<NUM>, <NUM>, or <NUM> of <FIG>) may be used to control the orientation of slide <NUM> within test chamber <NUM>. For example, a motor may move slide <NUM> laterally in test chamber <NUM>. In the intermediate position (<FIG>), slide <NUM> moves sample cavity <NUM> including a test fluid out of fluid communication with injection port <NUM>. My moving sample cavity <NUM> out of fluid communication with injection port <NUM>, fluid is prevented from spilling out of test chamber <NUM>. Thus, the intermediate position may allow the sample size in sample cavity <NUM> to be controlled. In the test position (<FIG>), sample cavity <NUM> is aligned with test port <NUM>. As sample cavity <NUM> is not enclosed (enclosing test cavity would prevent accurate XRF analysis), slide <NUM> should be moved into testing orientation so as to prevent the test fluid from spilling out of sample cavity <NUM>. In the test position, the XRF <NUM> may be used to analyze the drilling fluid. The sequence of a filling position, an intermediate position, and a test position allows the volume of the sample in sample cavity <NUM> to be maintained. The sequence also prevents fluid from overflowing from sample cavity <NUM> as the intermediate position is closed from the rest of the system, thereby preventing the injection side and the testing side of the system to be open at the same time.

Because XRF testing is sensitive to the location of the sample being tested, the motors (<NUM>, <NUM>, and <NUM> of <FIG>) may be used to ensure that the orientation of sample cavity <NUM> to XRF <NUM> is within a specific tolerance. By using an XYZ orientation analysis, the fluid analyzer can ensure that fluid sample tests are not distorted by blockage of the sample, as well as ensure that the sample does not overflow sample cavity <NUM>. Referring briefly back to <FIG>, in an embodiment wherein motor <NUM> controls slide <NUM>, slide <NUM> may be moved laterally within test chamber <NUM> to move a sample fluid from fluid communication with injection port <NUM> into orientation with test port <NUM>. During testing, motors <NUM> and <NUM> may be configured to change the orientation of either test chamber <NUM> or XRF <NUM>, thereby allow multiple tests from a single sample to be procured. Because the focal length between the XRF and the sample is important to maintain consistent and comparable results, the motors <NUM>, <NUM>, and <NUM> may work in concert to ensure that the distance between the sample fluid and test port <NUM> remains relatively constant. In certain embodiments, the gap between the XRF and the sample may be between <NUM> and <NUM>. Depending on the specifications of the XRF, this gap may be increased or decreased, thereby allowing the system to be customized to analyze particular fluids. In certain embodiments, the motors may be used to adjust the position of the XRF, thereby allowing multiple samples to be procured. In such an embodiment, the XRF may move in a substantially circular path, thereby allowing various portions of the sample to be tested. Specifically, the XRF may move laterally across the surface of the sample, while maintaining the same height above the sample, thereby allowing various readings to be taken across the surface of the sample. Additionally, because multiple readings of each sample may be procured, false readings may be avoided. For example, in certain embodiments, multiples readings are procured and a statistical average is performed or account for anomalies in the various readings.

Additionally, the temperature of the test chamber <NUM> and the sample may be controlled, thereby maintaining a constant volume of fluid and allowing the distance between the sample and XRF <NUM> to be the same among various tests. The temperature may be controlled by disposing a fluid conduit (not shown) in test chamber <NUM> proximate sample cavity <NUM>. A fluid, such as water, having a known and controlled temperature may be run through the fluid conduit thereby allowing the temperature of the sample fluid to be controlled. Controlling the sample fluid may help ensure that the XRF test is accurate between multiple samples. By controlling the location of the sample relative to XRF <NUM> and controlling the temperature, the results of the tests may be more accurate and provide better comparability between the results of multiple tests.

Referring to <FIG>, a cross-sectional view of the test chamber in fill and test positions, respectively, according to embodiments of the present disclosure are shown. During a testing process, slide <NUM> begins in a fill position (<FIG>), and a fluid solenoid (not shown) and an air solenoid (not shown) are opened, thereby allowing a sample of fluid to be injected from the active drilling fluid system into sample cavity <NUM>. When sample cavity <NUM> has the desired volume of fluid, the air and fluid solenoids are closed, thereby stopping the flow of fluid into test chamber <NUM>. Slide <NUM> is then moved into test position (<FIG>), such that sample cavity <NUM> is aligned with test port <NUM> and is configured to allow the XRF (not shown) to run a test sequence. After the test sequence, a pump (not shown) is actuated along with opening of the air solenoid, thereby purging sample cavity <NUM> of the sample fluid. When sample cavity <NUM> is purged, the pump is stopped and slide <NUM> is moved back into the fill position. Between the fill position and the test position, the sample may be held in an intermediate position (<FIG>). In the intermediate position, the sample may be temporarily held to allow the fluid to stabilize, thereby preventing an overflow. Depending on the properties of the fluid, the hold time may vary, for example, in certain embodiments, the sample is in an intermediate position between <NUM> seconds and <NUM> minutes, and in specific embodiments, the sample is in the test position for approximately <NUM> seconds.

Once in the fill position (<FIG>), a base oil cleaner may be injected into test chamber <NUM> and into sample cavity <NUM> by opening a base solenoid (not shown). The pump is then re-actuated, thereby purging any residual fluid or particulate matter from test chamber <NUM>. Slide <NUM> may then be moved back into the test position (<FIG>), and the pump actuated via opening of the air solenoid to further remove residual fluid and/or particulate matter from test chamber <NUM>. At this point, a subsequent fluid test may be performed. Those of ordinary skill in the art will appreciate that depending on the type of fluid being tested, the sequence of fill and test positions may vary. For example, in certain operations, only a single purge cycle may be required, while in other operations, three or more purge cycles may be required to adequately purge residual fluid and particulate matter from test chamber <NUM>.

Additional components may be included, such as a valve (not shown) on sample cavity <NUM>, which may be closed when the fluid is being tested. When such a valve is in a closed position, fluid would not be allowed to evacuate sample cavity <NUM>, thereby ensuring the sample volume remains constant. Opening of the valve may allow the fluid to be removed from sample cavity <NUM>, such as during a cleaning cycle. Other components may include cleaning devices. An example of a cleaning device that may be used with embodiments of the present disclosure is a wiper (not shown) disposed on or proximate test chamber <NUM>. The wiper may be used to clean injection port <NUM>, sample cavity <NUM>, or other portions of the system. In certain embodiments, the wiper may be disposed on slide <NUM>, thereby allowing both internal and external components of test chamber <NUM> to be cleaned. Additionally, a pump (not shown), such as a pneumatic pump may be in fluid communication with sample cavity <NUM>. The pump may be used to draw fluid into or out of sample cavity <NUM> during filling and cleaning cycles.

During XRF testing, a single sample may be tested multiple times. For example, once in the test position, the XRF <NUM> may be moved relative to test chamber <NUM> by actuation of one or more motors, thereby allowing the focus of the XRF to shift relative to sample cavity <NUM>. Because the portion of the sample fluid being tested is small relative to the total surface area of the sample exposed through sample cavity <NUM>, multiple tests not including an overlapping sample portion may be performed. In other embodiments, XRF <NUM> may be held in a constant position and test chamber <NUM> may be moved relative to XRF <NUM>, thereby providing another way for multiple tests to be performed. In still another embodiment one or more motors may be used move slide <NUM> relative to test chamber <NUM> and/or XRF <NUM>. In such an embodiment, the test chamber <NUM> and XRF may be held stable, and only slide <NUM> would be movable.

The XRF analyzer may be combined with the various other testing apparatuses described above, thereby allowing a single fluid analyzer to have a viscometer, electrical stability monitor, and XRF monitor. In such a configuration, the XRF may be disposed either before or after the viscometer or electrical stability monitor, as well as in a configuration to allow the separate tests to occur simultaneously.

As explained above, in order to conduct a stability test, fluid is drawn into a closed chamber having an electrical stability probe and a wiper that can be rotated into the gap in the probe to clean residue therefrom. In order to draw the fluid into the chamber, a series of solenoid valves work in conjunction with a pump, thereby allowing the volume of fluid in the chamber to be controlled. Once an acceptable temperature is reached, a test sequence is initiated. After the test is complete, the test fluid is withdrawn from the chamber and replaced with a cleaning fluid. To clean the device, a wiper is actuated with cleaning fluid present to remove residue that may have settled on the probe. In order to control the testing and cleaning, a programmable logic controller ("PLC") or micro processor is operatively coupled to the device, as will be explained in detail below.

To further explain the operation of a combined electrical stability, viscometer, and XRF analyzer, <FIG>, which is a process and instrumentation diagram for such a system is discussed below. As illustrated, an automated electrical stability meter <NUM>, a viscometer <NUM>, and an XRF analyzer <NUM> are placed in line with an active fluid system <NUM>. A plurality of valves <NUM> control the flow of fluids in and out of the automated electrical stability meter <NUM>, a viscometer <NUM>, and an XRF analyzer <NUM>. In certain embodiments, valves <NUM> may be solenoid valves, while in other embodiments, valves <NUM> may include check valves <NUM>, as discussed in detail above. Depending on the operational requirements of the system, a combination of solenoid <NUM> and check valves <NUM> may be used in certain systems. For example, as illustrated, fluid inlet line <NUM> and base fluid inlet line <NUM> are configured to provide a flow of fluid through solenoid valves <NUM> and then through check valves <NUM>. Thus, fluids that may include particulate matter that may clog valves <NUM> may flow through check valves <NUM>. However, water inlet <NUM> flows though valves <NUM> not including check valves <NUM>. Those of ordinary skill in the art will appreciate that in alternate embodiments, water inlet <NUM> may also flow through check valves <NUM>.

During operation fluid may flow through fluid inlet line <NUM> and into one or more of the automated electrical stability meter <NUM>, a viscometer <NUM>, and an XRF analyzer <NUM>. Those of ordinary skill in the art will appreciate that depending on the type of test required, fluid may flow into one, two, or all three of the analyzers, thereby allowing multiple tests to be performed simultaneously. In certain embodiments, it may be desirable for fluid to be tested by all three analyzers, while in other embodiments, only one or two of the tests may be run. Additionally, while <FIG> illustrates the analyzers being disposed in serial fashion, in alternate embodiments, multiple inlet lines may be used such that fluid may flow substantially simultaneously into each of the meters, or at least two of the meters.

As explained above, the system also includes a cleaning fluid tank <NUM> that is configured to provide a flow of base fluid to the automated electrical stability meter <NUM>, a viscometer <NUM>, and an XRF analyzer <NUM>, thereby allowing the analyzers to be cleaned between tests. The system also includes a pump <NUM> that is configured to remove tested fluids and cleaning fluids from the automated electrical stability meter <NUM>, a viscometer <NUM>, and an XRF analyzer <NUM>. The pump <NUM> may be used to pump fluids to waste drain and, in certain embodiments, back into active fluid system <NUM>. The system may further include an air supply <NUM> connected to an air inlet <NUM>, thereby allowing air to be injected into one or more of the automated electrical stability meter <NUM>, a viscometer <NUM>, and an XRF analyzer <NUM>.

The automated electrical stability meter <NUM>, a viscometer <NUM>, and an XRF analyzer <NUM> are also operatively connected to a micro-processor control <NUM>, thereby allowing the analyzers to collect and process data. The micro-processor control <NUM> is operative connected to a local storage memory <NUM> and a display <NUM>, thereby allowing collected and processed data to be stored and/or displayed. In certain embodiments, micro-processor control <NUM> may also be operatively connected to a remote connection <NUM>, such as an Ethernet connection, thereby allow collected and/or processed data to be sent or received remotely.

Those of ordinary skill will appreciate that, in view of the present disclosure, various combinations of analyzers may exist. For example, in certain embodiments, a system having all three of the automated electrical stability meter <NUM>, a viscometer <NUM>, and an XRF analyzer <NUM> may be used. In alternate embodiments, a system may include only the automated electrical stability meter <NUM> and the viscometer <NUM>, the automated electrical stability meter <NUM> and the XRF analyzer <NUM>, or the viscometer <NUM> and the XRF analyzer <NUM>.

Generally, the present disclosure is directed to a computer-assisted method for automated drilling fluid property analysis. The drilling fluid properties that may be analyzed/determined include viscosity, gel strength, and electric stability. Multiple configurations of drilling fluid analyzers are within the scope of the present disclosure. For example, in certain embodiments, the drilling fluid analyzer may be configured to determine electric stability, while in other embodiments the drilling fluid analyzer may be configured to determine gel strength, viscosity, or combinations thereof. Regardless of whether the drilling fluid analyzer is configured to determine one or more combinations of electric stability, gel strength, and/or viscosity, the system for determining the properties will be operatively connected to a computer for the determination of the specific property or properties. The computer, whether local or remote, includes a software application executing on a processor.

The software application includes instructions for causing a drilling fluid to be transferred from an active fluid system to a sample cell. The amount of drilling fluid transferred may vary depending on the requirements of a particular operation; however, generally, a <NUM> liter sample will be transferred from the active drilling fluid system to a sample cell of the fluid analyzer. After the sample cell is filled with a desired amount of fluid, the fluid may be directed into contact with electrodes of an electric probe. As a voltage is applied across the electrodes of the electric probe, the fluid analyzer determines when the fluid conducts a charge across the electrodes, the data is recorded, and an electric stability may be determined based on the applied voltage. Those of ordinary skill in the art will appreciate that the above method will allow for the determination of the electric stability, and thus the emulsion stability of oil-based or synthetic-based drilling fluids.

In certain embodiments, the recorded data may be stored locally until testing is complete, while in other embodiments, the data may be transferred to a remote data store for either storage or remote processing. Depending on the amount of data, number of tests, etc., the data maybe be transferred after each test or in batches.

The length of the test may vary based on the properties of the drilling fluid. For example, a single test may last <NUM> minutes or longer in certain embodiments, while in other embodiments, a new test may be performed every couple of minutes. In order to increase the accuracy of the determined drilling fluid property, a single sample fluid may be tested multiple times. For example, a single fluid may be tested five times, and if any outlier results are detected, the outlier results may be excluded from the sample results used in determining the final fluid property.

After the test is performed, the fluid analyzer may perform a cleaning cycle, by discharging the fluid sample and injecting a cleaning fluid into the sample cell. The cleaning fluid may include a base oil, such as diesel, mineral oil, or other bases to the particular fluid in the active drilling fluid system, or may include other additives, such as surfactants or water to further clean the sample cell. During the cleaning cycle, the wiper may be rotated through the probe, thereby cleaning the surfaces of the probe, as well as agitating the cleaning fluid in the sample cell to remove particulate matter that may have settled on other surfaces of the sample cell.

The time the cleaning fluid remains in the sample cell may be modulated based on particular properties of the fluid. For example, a fluid with high viscosity may require a longer cleaning cycle, or fluids with high levels of low gravity solids or weighting agents that may adhere to the surfaces of the sample cell may require longer cleaning cycles to thoroughly remove. The cleaning cycle may includes multiple rotations of the wiper, as well as one or more additions of cleaning fluid to the sample cell. In certain embodiments, the cleaning cycle may also include additions of water or air to further remove a tested fluid sample from the sample cell prior to sampling of a subsequent fluid sample.

After the sample cell is clean, the fluid analyzer may be instructed to discharge the cleaning fluid and transferred a second sample from the active drilling fluid system into the sample cell. Depending on the specifics of the operation, a specified volume of drilling fluid may be cycled from the active drilling system through the fluid analyzer prior to filling the sample cell, thereby ensuring that the second sample does not contain residual fluid remaining in the line from the original test. For example, in certain embodiments, fluid may be allowed to run through the fluid analyzer from the active drilling system for a set period of time or until a specific volume of fluid has passed through the system. When it is determined that the fluid passing through the system is acceptable for sampling, the sample cell is filled, and a second test cycle may begin.

In other embodiments, the fluid analyzer may also include a viscometer configured to allow the fluid analyzer to collect data for determining the gel strength and/or viscosity of a sample drilling fluid. Similar to the test described above, after a sample fluid is transferred from the active drilling fluid system into the sample cell, the fluid is directed to an area between a sleeve and bob of a viscometer. Depending on the configuration of the viscometer, either the sleeve or bob is rotated at a specific speed. The response of the fluid to the rotational speed of the sleeve or bob is recorded, and the data is either stored or sent to a remote computer system for processing, as described above with respect to the electric stability test.

The rotational speed of the sleeve or bob may also be varied in order to more accurately determine the gel strength of the fluid. For example, the sleeve or bob may be rotated at <NUM>, <NUM>, <NUM>, and/or <NUM> revolutions per minute ("RPM"). Those of ordinary skill in the art will appreciate that the rotational speed may vary based on the specifics of the drilling operation or the requirements of the analysis.

In certain embodiments, both electric stability tests and viscosity and/or gel strength tests may occur substantially simultaneously. Thus, the length of time required for the test may be decreased. Additionally, other steps may occur before, after, or during a specific test. For example, a temperature of the sample fluid may be adjusted, and/or the sample cell may be pressurized. The test may also be adjusted via a remote computer during the test if an operator determines that the fluid analyzer is not performing as desired.

The progression of the test, including the specific parameters of the test, may be pre-programmed, such that the tests may be fully automated. For example, a drilling operator may adjust specific fluid analyzer parameters including the number of tests to be performed on a single sample, the number of samples to be tested, the frequency of the tests, the sample size to be tested, the temperature of sample fluid, the voltage applied, the rotational speed of the viscometer, the pressure applied to the sample cell, number of cleaning cycles, type of cleaning cycle, etc. The specific parameters may then be input as a test package, either locally or remotely, and the fluid analyzer may automatically being testing. Should a condition occur that requires manual adjustment, a local operator or remote operator may override the programming, adjusting one or more of the analyzer parameters, thereby allowing for optimization of the testing.

As explained above, the fluid testing may include a series of tests that are preprogrammed either from a remote location or from a local control. In order to control and/or monitor the testing, a drilling operator may also have one or more control panels showing multiple displays. The graphical user interface ("GUI") that is displayed to an operator may change based on the particulars of the operation; however, exemplary GUIs are described below as an indication as to the type of displays that may be used.

Referring initially to <FIG>, a local display according to embodiments of the present disclosure is shown. In this embodiment, the local display includes a menu for selecting specific types of tests, calibration modes, etc. As illustrated, local display may include an auto test selector <NUM>, a 500V selector <NUM>, a 1900V selector <NUM>, an air test selector <NUM>, a water test selector <NUM>, a setup selector <NUM>, a data display selector <NUM>, a diagnostic selector <NUM>, and a utilities selector <NUM>.

Prior to operation, one or more test cycles may be programmed, thereby allowing for automation of the entire testing process. In addition to test cycles, calibration tests may also be performed. For example, in one embodiment, the device includes a 500V test that allows the operator to verify the calibration of the probe against an internal resistor network. The device may also include a 1900V test that allows the operator to verify the calibration of the probe against an internal resister network. The results of the tests may be displayed on a data display page such as that displayed in <FIG>.

Other embodiments may include an air test and/or a water test. As air is a relatively good insulator, the test should result in a high voltage reading of approximately 1900V and fall within about <NUM>% of the 1900V requirement. As water is a conductor, the test should result in a high voltage reading of approximately 500V and fall within about <NUM>% of the 500V requirement. If the tests do not fall within an acceptable range, the operator may be notified that the device is not in condition to perform automated testing.

During calibration of the device, a cleaning cycle is initially performed. In the cleaning cycle, existing fluid in the chamber is discharged, cleaning fluid fills the chamber, and the probe is automatically cleaned. After the cleaning cycle, an electronics test is performed, in which the probe is internally disconnected and the voltage is ramped up to a maximum. After the electronics test, an air test is performed, in which cleaning fluid is discharged from the chamber, air is allowed to fill the vessel, and the probe is reconnected and voltage is ramped up to maximum. After the air test is performed, a water test is performed, in which the test vessel is filled with water, the voltage is ramped up, and the electrical stability threshold of 3V is compared to the test voltage. The last step in calibration is determining meter accuracy. In this step, the probe is disconnected and internal resisters and Zener diodes are used to check the accuracy of the meter running at 500VAC and 1900VAC.

In order to setup a test, a number of different options may be selected by the operator. Referring to <FIG>, example setup test displays according to embodiments of the present disclosure are shown. Initially, an operator may determine a number of profiles correspond to the number of tests that will be performed. The user may also select a number of ramps, number of wipes, mud transfer in duration, cool down duration, temperature hold times, delay between ramps, cycle delays, pressure set points, base fluid in duration, base soak durations, and various temperature set points. Each selection may be adjusted based on the requirements of the drilling operation and/or the requirements of a particular test.

Referring to <FIG>, the local display may be selected so a viewing may observe current testing data. Other displays that an operator may select to view include a system status page, such as that displayed in <FIG>. The systems status page may allow an operator to view the condition of the wiper, motor, structure of the unit, condition of one or more valves, the condition of the relays, a voltage reading, current reading, temperature reading, and/or pressure reading.

Navigating between the different displays may be achieved via multiple types of interfaces such as, for example, peripheral devices, keyboard, and/or touch screens. Those of ordinary skill in the art will appreciate that all of the discussed displays as well as additional displays may be present in a particular device, depending on the requirements of a drilling operation.

As explained above, the device may have a local display, as well as a remote display. The remote display allows the device to be controlled and the testing monitored remotely. Different methods of establishing a connection between the device and a remote control facility may be used. In one embodiment, the device may be connected to an Ethernet network, thereby allowing device to be accessed remotely over the Internet. In other embodiments, the device may be connected through a virtual private network ("VPN"), thereby allowing connection between the device and any personal computer logged into the network. In still another embodiment, the device may be accessed remotely by connecting the device to a network router.

While operating in remote mode, an operator may monitor and/or control the testing, including, for example, initiating calibration tests, inputting testing parameters, loading new testing profiles, and viewing the results of the test. Examples of remote displays are illustrated in <FIG>. <FIG> is a display of an automatic results page, <FIG> are displays of calibration modes, <FIG> is a display of the setup screen, <FIG> is a display of the test data screen, and <FIG> is a display of a diagnostics screen.

Those of ordinary skill in the art will appreciate that the specific displays may vary according to the specific components of the device. While the displays discussed above are specific for a device for testing electrical stability of a fluid the same and additional options may be available for a device capable of determining gel strength and/or viscosity.

Referring to <FIG>, a flow chart of an exemplary operations sequence according to methods of the present disclosure is shown. During a typical testing cycle an operation may select a start option <NUM> to initiate a testing sequence. Before actual testing begins, the probe may be cleaned by instituting a cleaning cycle <NUM>, ensuring that any residual fluid that may have adhered to the probe is removed. After the device is cleaned, drilling fluid is transferred <NUM> from an active drilling fluid system through the inlet as cleaning fluid is removed from the device. The sample fluid is then heated <NUM> to a particular temperature, for example between <NUM> and <NUM>. When the desired temperature has been achieved, the voltage is ramped up <NUM> at a rate of about 150V/s at <NUM>. The current is then monitored <NUM> until <NUM> microamps are detected or 2000V are provided. The results are stored <NUM> for later transference to a remote facility for processing <NUM> or other use for local processing <NUM>. The steps of ramping the voltage <NUM>, monitoring <NUM>, and storing the results <NUM> are subsequently repeated <NUM> until the desired number of tests have been completed.

Various additional steps may be added in specific applications, thereby allowing the device to collect additional data. For example, in certain operations, the chamber of the device may be pressurized, thereby decreasing the amount of heat required to increase the temperature. In certain operations, the pressure may be increased within a range of <NUM>-<NUM> bar.

During testing, a single fluid sample may be tested multiple times, at different temperatures. The multiple tests may be used to remove outliers that may otherwise skew the results. Additionally, in gel strength tests, a single fluid may be tested at various temperatures and at different rotational speeds. For example, the sleeve or cup of the viscometer may be rotated at <NUM>, <NUM>, <NUM>, and <NUM> RPMs, thereby allowing the gel strength to be determined.

After the data is collected and stored <NUM>, one or more drilling fluid properties, such as viscosity, gel strength, and/or electric stability are determined <NUM>. The determined results may then be displayed directly on the device or otherwise displayed through a web server. In certain embodiments, the results may also be provided <NUM> to the Wellsite Information Transfer specification ("WITS") as a specific user-defined record. After all tests on a specific fluid are performed, a subsequent cleaning cycle may be initiated <NUM>. In the subsequent cleaning cycle, the discharge valve is opened <NUM>, the cleaning fluid pump actuated <NUM>, and cleaning fluid is transferred <NUM> into the device. The wiper motor is then started <NUM>, thereby cleaning the surfaces of the device, probe, viscometer, etc. The device is then in condition to test a subsequent fluid sample.

Embodiments of the present disclosure may be implemented on virtually any type of computer regardless of the platform being used. For example, as shown in <FIG>, a computer system <NUM> includes one or more processor(s) <NUM>, associated memory <NUM> (e.g., random access memory (RAM), cache memory, flash memory, etc.), a storage device <NUM> (e.g., a hard disk, an optical drive such as a compact disk drive or digital video disk (DVD) drive, a flash memory stick, etc.), and numerous other elements and functionalities typical of today's computers (not shown). In one or more embodiments of the present disclosure, the processor <NUM> is hardware. For example, the processor may be an integrated circuit. The computer system <NUM> may also include input means, such as a keyboard <NUM>, a mouse <NUM>, or a microphone (not shown). Further, the computer system <NUM> may include output means, such as a monitor <NUM> (e.g., a liquid crystal display (LCD), a plasma display, or cathode ray tube (CRT) monitor). The computer system <NUM> may be connected to a network <NUM> (e.g., a local area network (LAN), a wide area network (WAN) such as the Internet, or any other type of network) via a network interface connection (not shown). Those skilled in the art will appreciate that many different types of computer systems exist, and the aforementioned input and output means may take other forms. Generally speaking, the computer system <NUM> includes at least the minimal processing, input, and/or output means necessary to practice embodiments of the present disclosure.

Further, those skilled in the art will appreciate that one or more elements of the aforementioned computer system <NUM> may be located at a remote location and connected to the other elements over a network. Further, embodiments of the present disclosure may be implemented on a distributed system having a plurality of nodes, where each portion of the present disclosure (e.g., the local unit at the rig location or a remote control facility) may be located on a different node within the distributed system. In one embodiment of the invention, the node corresponds to a computer system. Alternatively, the node may correspond to a processor with associated physical memory. The node may alternatively correspond to a processor or micro-core of a processor with shared memory and/or resources. Further, software instructions in the form of computer readable program code to perform embodiments of the invention may be stored, temporarily or permanently, on a computer readable medium, such as a compact disc (CD), a diskette, a tape, memory, or any other computer readable storage device.

The computing device includes a processor <NUM> for executing applications and software instructions configured to perform various functionalities, and memory <NUM> for storing software instructions and application data. Software instructions to perform embodiments of the invention may be stored on any tangible computer readable medium such as a compact disc (CD), a diskette, a tape, a memory stick such as a jump drive or a flash memory drive, or any other computer or machine readable storage device that can be read and executed by the processor <NUM> of the computing device. The memory <NUM> may be flash memory, a hard disk drive (HDD), persistent storage, random access memory (RAM), read-only memory (ROM), any other type of suitable storage space, or any combination thereof.

The computer system <NUM> is typically associated with a user/operator using the computer system <NUM>. For example, the user may be an individual, a company, an organization, a group of individuals, or another computing device. In one or more embodiments of the invention, the user is a drill engineer that uses the computer system <NUM> to remotely access a fluid analyzer located at a drilling rig.

Advantageously, embodiments disclosed herein may provide an automated system for determining an electric stability, viscosity, and/or gel strength of a fluid, such as a drilling or completion fluid. The automated system may be capable of being controlled from a remote location, as well as executing various sampling and testing protocols, so as to allow the system to run without significant manual oversight. The system may also provide for more robust and accurate analysis, as a single sample of fluid may be tested multiple times thereby allowing the system or operator to remove outliers and/or false readings.

Also advantageously, the system may be a closed system, thereby allowing the pressure to be controlled. Control of the pressure may thereby also the boiling point of a sample to be adjusted, so that the temperature required during the testing may be decreased. The closed system may also provide for more accurate measurements, and the pressure can be readily controlled, modulated, and monitored. Accordingly, pressure or temperature sensitive measuring devices or components may be less likely to be affected during routine operation.

Advantageously, embodiments of the present disclosure having a magnetic coupling may provide more accurate results due to reduced seal drag. Also, as the viscosity, electrical stability, and gel strength tests may be performed simultaneously, the time required to determine the respective drilling fluid properties may be reduced. Because the data may be transmitted and properties determined in real-time, the drilling fluids at the rig may be adjusted as required, thereby decreasing the overall cost of drilling, as well as potentially decreasing the likelihood of rig damaging events, such as blowouts.

Claim 1:
An automated electrical stability meter for measuring electrical stability of a sample of fluid, the meter comprising:
a housing having an inlet (<NUM>) and an outlet (<NUM>);
at least one actuated valve (<NUM>) disposed proximate the inlet (<NUM>) and configured to open and close to provide a sample of fluid into the housing;
an electronic control module (<NUM>) configured to send a signal to the at least one valve; and a probe assembly (<NUM>) operatively coupled to the electronic control module (<NUM>), the probe assembly (<NUM>) comprising:
an electrode probe (<NUM>) having two electrodes (<NUM>) and a probe gap (<NUM>) therebetween; and characterized by
a cleaning mechanism (<NUM>) configured to periodically clean the probe gap, and
an agitator (<NUM>) coupled to the cleaning mechanism (<NUM>) and configured to agitate the sample of fluid in the housing.