Ultrasonic Rig

Main applications:

1. Detecting and quantifying gas hydrates in sediments by physical techniques.
2. Effect of sediment mineralogy and/or over burden pressure on the phase behaviour of gas hydrates in sediments.
3. Simulating various formation and dissociation scenarios for natural gas hydrates.
4. Simulating various gas production techniques from natural gas hydrates.
5. Investigating the effect of LDHIs on gas hydrate formation and inhibition.
6. Measuring acoustic properties of various fluid systems.
7. Measuring saturation pressure using ultrasonic techniques

Operating conditions:

Pressure: up to 6,000 psia (40 MPa)
Temperature: -20 ºC to 80 ºC

Description:

The Ultrasonic Rig consists of a stainless steel cell which is filled with real or artificial unconsolidated sediments or consolidated rock cores. The cell is surrounded by a coolant jacket with circulating fluids controlled by a programmable cryostat (253 to 353 K) and is stable to within 0.05K. The system has a maximum operating pressure of 41 MPa. Sediment overburden and pore fluid pressures can be controlled independently. Temperature and pressures are monitored by means of a PRT and Quartzdyne pressure transducers (accuracy of 0.01MPa), respectively. At the two ends of the cell, an ultrasonic transmitting transducer and a receiving transducer are mounted in each end cap. Transducers can be compressional or shear, or combinations of P-wave and S-wave at a central frequency of 1MHz. An ultrasonic pulser/receiver (P/R) is connected to the two transducers to generate and receive pulse signals. The received signal through test sediments is amplified by the P/R and the sent to a digital storage oscilloscope (DSO). The DSO acquires the series of pulse waves and sends data to a personal computer (PC) through a parallel port interface. The PC shows waveforms on its screens and saves data in both waveform and data format for further processing.