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Drilling & Stimulation Properties
The Visualizing Simulation System of Proppant Transportation
The Visualizing Simulation System of Proppant Transportation (VSSPT) is designed
to evaluate the proppant transport capabilities of various fracturing fluids. This
is done by pumping a slurry of frac gel and proppant through a shear loop to condition
the fluid and simulate downhole conditions. The slurry is then pumped through a
series of pipes to measure the shear stress exhibited by the slurry at different
shear rates. Using this shear stress vs. shear rate data the rheological properties
of the slurry can be determined (n’, k’, apparent viscosity). Following the pipe
rheometer the slurry is flowed through a slot rheometer where the proppant transport
can be visualized. By comparing the rheological properties of the slurry with the
actual proppant transport observed the user can have a better understanding of the
proppant transport of fluids on location when it is impossible to visualize the
actual proppant transport. Studies can be conducted to determine the optimum fluid
properties that will maximize proppant transport but minimize formation damage.
In addition, the settling properties of the proppant in various types of frac gel
can also be investigated.
General Specifications
- Max working pressure through the slot: 30psi (0.20MPa)
- Max working pressure bypassing the slot: 35 psi (0.24MPa)
- Max working temperature through the slot: 150F (65.6C)
- Max working temperature bypassing the slot: 250F (121.1C)
- Max flow rate: 2.5 GPM (9.5 L/MIN)
- Proppant Concentration Range: batch mixed between 0.5 to 10 lbs/gal (60 to 1200 kg/m3)
- Overall Room Size: 15 meters wide by 7 meters deep by 3 meters ceiling height
(Minimum. A longer room may be needed depending on the final layout)
- Electrical: 380 VAC 50 Hz 3 Phase 60 Amps (5 outlets minimum), 220-240 VAC 50 Hz 1
phase 20 Amps (5 outlets minimum)
Main Components
Mainly consisting of the following subsystems:
- Fracturing Fluid Mixing and Pumping
- Heating and Shearing
- Pipe Rheometer
- Slot Rheometer
- Fluids Disposal
- Data Acquisition
Mixing and Pumping/Pressuring Subsystem
Applications: mixing and pumping/pressuring the fracturing fluid
- Preparing and reserving the gel with flowing ability
- Mixing pump
- Open-cap plastic tanks with blenders
- Plumbing and valves, plastic
- Variable-speed slurry pump capable of pumping a 40# guar slurry with 4 lbs/gal (479 kg/m3) of
proppant at a maximum rate of 2.5 gpm
- Cross-linking pump
- Linear flow-meter with nominal pressure of 500 psi (3.5 MPa)
Heating and Shearing Subsystem
Applications: heating and shearing the fracturing fluid
- Well bore shear simulator for shear rates of up to 1000 sec-1 at
room temperature for a period of one (1) minute. Shear rate based based
upon at flow rate of 2.5 GPM (9.5L/MIN). Wetted material: 316 Stainless Steel
- Heating System, Heating range: room temperature to 250F (121.1C); pumping speed
up to 2.5 GPM (9.5L/MIN) then shearing at 40sec-1 in the loop for 5 minutes.
Wetted material: Stainless Steel.
-
NOTE: Slot Rheometer is only rated to 150F (65.6C), and must be removed from
the system flow path if the system temperature is increased above 150F (65.6C).
- Temperature measurement at outlet of heat exchanger
- Heating oil to be specified by Core Lab, but provided by the customer
Pipe Rheometer
Applications: maintaining the fluid temperature, and measuring rheological properties
- Three (3) different sizes tubing (different diameter and different length)
- Six (6) differential pressure transducers, accuracy +/-0.1%, for measuring viscosity
utilizing custom designed connections.
- Three (3) high range and three (3) low range transducers
- Can measure the rheological properties at user-selected fluid temperature
- Connected in series
- Wetted material: 316 Stainless Steel
- Temperature measurement at outlet of the pipe rheometer
Slot Rheometer
Applications: visualizing the performance/properties of the slurry proppant transportation
- Width of the slot: 0.2” (5 mm) approximate
- Single inlet perforation
- Shear rate in the slot: 35S-1 @ 2.5 GPM (9.5L/MIN)
- Visualization system equipped
- Lighting device equipped
- Wetted material: 316 Stainless Steel and Lexan
- Temperature measurement at inlet of Slot Rheometer
- No heating in the Slot Rheometer
Fluid Disposal Subsystem
Applications:
- Cooling loop (for temperatures greater than 212 F, 100C)
- Plastic metering/collecting tank
- Visualized metering container
Data Acquisition Subsystem
Applications: test procedure control and data acquisition and processing
- Low level automation
- PC with monitor
- Monitoring pressure, flowrate, temperature, and working status of each section
- Data acquisition software under MS Windows XP, and output data can be output into
Excel for further analysis.
- User can display and process the data in real time.
- User can change the time-interval of data acquisition in real time
- PC can calculate and print the curves of "pressure, shear stress, or temperature vs time".