Ultrasound Testing System for the Detecting of the Shape and Growth of a Vapor Chamber in the VAPEX Process
Acoustic wave detection systems are designed to estimate distances based on the measurement of the time of arrival (TOA) of an ultrasonic wave. It has been used in diagnoses and treatments in areas such as medicine, dentistry, civil engineering, and many other industrial applications. It has also been applied in the oil industry for pipeline inspection and fluid velocity measurement. In this study, a comprehensive experimental program was designed and conducted to evaluate the feasibility of using acoustic waves for detection and monitoring of vapor chamber growth and pressure front movement in porous media during vapor chamber expansion in the VAPEX process. Vapor extraction is a potential nonthermal recovery process used to improve the recovery factor from heavy oil and bitumen reservoirs. In this process, a mixture of light hydrocarbon vapors close to its dew-point, such as propane or butane, is injected into the reservoir through a horizontal injection well. As the solvent vapor comes into contact with the heavy oil, it dissolves in the oil and reduces its viscosity. The mobilized oil then drains into the second horizontal production well. After the breakthrough of the vapor chamber from injection to production well, the vapor chamber begins to grow and more oil becomes mobilized by interaction with the solvent chamber. The simulated VAPEX chamber in this study was conducted by using different sized air balloons buried in a water- or oil-saturated sand pack. The ultrasound receivers were placed on the physical model to detect the acoustic signals from the transducers. A MatlabTM based program was developed to do the signal processing using wavelet signal transform technique to extract the position of the echo signal from the signal record; the size and shape of the air balloons were determined based on the TOF of the ultrasonic signal record. The results of the measurements and simulations show that ultrasound detection system is applicable to test the shape and growth of simulated VAPEX chamber in a lab scale; the image results of the simulated lab model are reliable. It is the first time that such a technique has been proposed for this purpose and it was proven effective on a laboratory scale.
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Faculty of Graduate Studies and Research, University of Regina