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High Pressure Simulator
The workhorse of the WCTC is the high-pressure simulator (HPS) which is a vertical, variable-width parallel plate flow cell capable of operating at elevated temperature and pressure. The internal dimensions of the slot are 7 ft. (2.13 m) high and 9 1/3 ft (2.84) long, formed by two faced, one fixed and the other movable by servo control. The operational limits of the HPS are 1200 psi (827 kPa) internal pressure and 250 degrees F (121(C). Slot width can be adjusted dynamically over the range of 0 to 1.25 inch (3cm) by a system of 12 hydraulically actuated platens. The servo controllers on the individual platens allow the operator to maintain the parallel plate geometry I response to temperature gradients, pressure gradients, and any other factors tat would distort the slot geometry. Each platen is 28 inches by 28 inches (0.71 m x 0.71 m) square and the platens are laid out in a 3 by 4 matrix to form one face of the simulated fracture.

Each platen surface is covered with a replaceable simulated rock facing which is instrumented with the data acquisition system. The facings simulate rock surfaces and can be made with the desired permeability and texture. Therefore by changing the facings, different permeabilities and different surface properties such as texture and topology, can be investigated for their effects on the flow behavior and proppant transport. The movable face is lined with the desired facing which is one inch (2.5 cm) thick. The opposite fracture face is a 6 inch (15cm) thick solid slab of steel covered with a matching 3 by 4 matrix of one inch thick facing having the same characteristics as those on the movable side. Behind each facing is a system of collection channels which route fluid leakoff to the outside of the flow cell for measurement.

Inlet and exit manifolds are 2 3/4-inches (7cm) in diameter, each equipped with 22 perforations which are 1/2-inch (1.27 cm) in diameter and on a four inch (10 cm) spacing. Inlet manifold perforation configuration and size can be easily changed using a series of blank and sized inserts.

The dimensions of the facing are 25 1/8- inches by 25 1/8 inches and 1 inch (0.63 m x 0.63 m x 2.5 cm) thick. The different types of facing employed are resin, synthetic rock, and natural rock. The resin facings are smooth and impermeable, while the synthetic and natural rock facings have more texture and are permeable. Examples of instrumentation on the impermeable facings are fiber optics for vision system, sight glass for Laser Doppler Velocimetry (LDV), differential pressure tube, and thermocouple lead.