CRUDE OIL SEPARATOR DEVICE USING ULTRASONIC WAVES
The present application is a continuation of pending provisional patent application Serial No. 60/417,712, filed on October 10, 2002, entitled "Crude Oil Separator Device Using Ultrasonic Waves".
BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to a crude oil separator device and, more particularly, the invention relates to using ultrasonic waves in conjunction with a crude oil separator device for separating gas, oil, and water.
2. Description of the Prior Art The oil industry is continuously moving into deeper offshore sites to look for oil in order to meet the rising demands of the market. The availability of space is one of the major constraints while operating an offshore platform. In addition, the investments involved in constructing and maintaining the equipment are very large as compared to the investments of an onshore facility of the same magnitude. Separators are some of the key pieces of equipment present on a platform. The primary function of a separator is to separate the water and gas from the crude oil (in more cases than not, all three mentioned fractions will be present in the crude oil). Hence, there is a need to have a separator that will handle a specific flow rate of crude oil, at a specific temperature and pressure, and achieve the required separation of the three components (i.e. oil, water and gas). Currently many different kinds of separators are in use in the industry. The inventors of the present application have demonstrated that ultrasonic waves increase the efficiency of operation and hence smaller separators can be used to do the same volume of separation as a larger one that does not use the ultrasonic waves. This saves space on an offshore platform and will reduce the size and therefore the cost for onshore installations.
SUMMARY The present invention is a crude oil separator system for receiving liquids and separating gas, oil, and water. The crude oil separator system has a separator with an inner surface. The crude oil separator system comprises an ultrasonic generating device for generating ultrasonic waves. The present invention further includes a method for separating gas, oil, and water from liquids. The method comprises providing an ultrasonic generating device and generating ultrasonic waves.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view illustrating experimental setup devised to quantify the increase in gas/water/oil separation using ultrasonic waves; and FIG. 2 is a schematic view illustrating a crude oil separator device using ultrasonic waves, constructed in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As illustrated in FIGS. 1 and 2, the present invention is an ultrasonic wave generating device, indicated generally at 10, for use with a gas/oil/water separator device 12. The separation of the gas/oil/water mixture within the separator device 12 is enhanced by using ultrasonic waves. The ultrasonic waves are generated by the ultrasonic wave generating device 10 attached to the inner surface of the conventional separator or operated as a separate unit. Each oil/gas/water system is analyzed separately to determine the exact frequency of the ultrasonic wave generating device 10 at which the separation efficiency is at a maximum. The separator 12 of the present invention uses ultrasonic waves and can be used as an individual unit or the ultrasonic wave-generating device 10 can be attached inside an existing separator devices 12 to increase their efficiency. However, since the actual design of the separator device 12 varies from manufacturer to manufacturer, the ultrasonic wave generating device 10 of the present invention can be specifically designed taking into account the design of the separator device and the operating conditions in mind. During a study on the effect of ultrasonic waves on paraffin wax deposition, the inventors of the present application observed that the effect of application of
ultrasonic was two folds. Firstly, the ultrasonic waves create a wave-like pattern that was decreased the amount of wax deposited during the experiment. Secondly, the inventors of the present application also observed (visual observation) that when ultrasonic waves were applied to the oil, a significant quantity of gas bubbles (dissolved gas) evolved from the container containing the oil, whereas no gas had been visible prior to the application of ultrasonic waves. Ultrasonic waves generated by the ultrasonic wave generating device 10 have the effect of creating gas filled cavities in liquids which then collapse violently. The collapsed cavities serve as nucleation points for the release of dissolved gas. The setup of the equipment is illustrated in FIG. 1. The details of the working separator device 12 are illustrated in FIG. 2. The following dimensions of the separator device 12 were used, although other dimensions are within the scope of the present invention: Length = 18 cm (0.18 m) Diameter = 10 cm (0.1 m) Total volume = ( I/4) * L * D2 = (π/4) * 18 * (10)2 = 1413 cm3 = 1413 ml = 1.413 L
The separator device 12 is operated at about half its total volume. Representative figures are as follows: Operating volume = 700 ml or 0.7 L Residence time (t) = 15 - 20 min Volumetric flow rate (q) = (0.7/15) L/min = 0.0466 L/min = 46.66 ml/min = (0.7/20) L/min = 0.035 L/min = 35 ml/min
Hence, the Operating Volumetric flow rate = 40 ml/min.
The inlet tank 14 containing the crude oil has a Jknown gas to oil ratio (GOR 1). This ratio is obtained by dissolving a Jknown quantity of gas in the inlet tank 14. The crude oil, after being processed in the separator device 12 is stored in a separate storage or outlet tank 16. The gas to oil ratio of the storage 16 tank is measured at the end of the experiment. The rates of oil and gas coming from the storage tank 16 are
used to determine the gas oil ratio of the oil at the inlet 18 and the outlet 20 of the separator device 12 and, hence, the efficiency of separation can be determined.
Total time for the experiment, T Initial Gas to Oil ratio, Gl Final Gas to Oil ratio, G2
Hence, the amount of gas separated in the separator device 12 without the application of Ultrasonic waves = GS 1 = (Gl - G2)*q*T.
During experiments, the process was carried out multiple times first with no ultrasonic treatment being applied to the separator device 12 and secondly with the application of ultrasonic waves. The amount of gas separated in the separator device 12 with the application of ultrasonic waves based on similar calculations as shown above = GS 2
% Increase in efficiency = (GS2 - GS 1) * 100 / GS 1.
The foregoing exemplary descriptions and the illustrative preferred embodiments of the present invention have been explained in the drawings and described in detail, with varying modifications and alternative embodiments being taught. While the invention has been so shown, described and illustrated, it should be understood by those skilled in the art that equivalent changes in form and detail may be made therein without departing from the true spirit and scope of the invention, and that the scope of the present invention is to be limited only to the claims except as precluded by the prior art. Moreover, the invention as disclosed herein, may be suitably practiced in the absence of the specific elements which are disclosed herein.