Multiphase flows sensor response database

\n The application of multiphase flowmeters has started to grow significantly in recent years; one factor which has contributed to the acceptability of multiphase metering is the availability of multiphase test facilities where meters can be subjected to a realistic range of operating conditions. Such facilities are available at the National Engineering Laboratory (NEL) in the United Kingdom and at the Institut français du pétrole (IFP) in France and have been used both during development of multiphase flowmeters and for evaluation of commercially available multiphase flowmeters. The objective of the current project was to examine the performance of a simple system consisting of a venturi meter and 137Cs gamma densitometer in both test facilities in order to gain some understanding of the comparative behaviour of the facilities. The measurement system was chosen to avoid any commercial bias in the testing and also to give direct access to the sensor responses which is valuable in interpreting the measurements. The test facilities are described in the paper, together with a presentation of the results and conclusions of the venturi meter tests in the two facilities.\n

The oil and gas industry need for high performing and low cost multiphase meters is ever more justified given the rapid depletion of conventional oil reserves that has led oil companies to develop smaller and marginal fields and reservoirs in remote locations and deep offshore, thereby placing great demands for compact and more cost effective solutions of on-line continuous multiphase flow measurement for well testing, production monitoring, production optimisation, process control and automation. The pattern recognition approach for clamp-on multiphase measurement employed in this study provides one means for meeting this need. High speed caesium-137 radioisotope-based densitometers were installed vertically at the top of a 50.8mm and 101.6mm riser as well as horizontally at the riser base in the Cranfield University multiphase flow test facility. A comprehensive experimental campaign comprising flow conditions typical of operating conditions found in the Petroleum Industry was conducted. The application of a single gamma densitometer unit, in conjunction with pattern recognition techniques to determine both the phase volume fractions and velocities to yield the individual phase flow rates of horizontal and vertically upward multiphase flows was investigated. The pattern recognition systems were trained to map the temporal fluctuations in the multiphase mixture density with the individual phase flow rates using statistical features extracted from the gamma counts signals as their inputs. Initial results yielded individual phase flow rate predictions to within ±5% relative error for the two phase airwater flows and ±10% for three phase air-oil-water flows data.

In this paper the airspeed control in an open circuit wind tunnel for a velocity range from 5 m/s to 25 m/s is presented. The instrument used for the velocity measurement was a type L Pitot tube, differential pressure, absolute pressure and temperature transducers were used too. Open loop tests were developed in the wind tunnel to determine modeling it through the Toolbox for system identification of MATLAB® for the design of the reference speed control strategy. By the process of identification the PI controller that is capable of maintaining a variation of ±2% with respect to the set point was obtained.

The potential error of estimating the small pressure gradient under a directional wave field through the subtraction or comparison of relatively large total-head signals from adjacent pressure transducers in an array is avoided through the use of differential pressure transducers which measure directly the pressure gradients. A device which utilizes four differential pressure tranducers placed orthogonally about one absolute pressure transducer, (the "DPG"), was developed and field-tested at the U.S. Army Corps of Engineers Coastal Engineering Research Center Field Research Facility, Duck, North Carolina. The first five directional Fourier coefficients of the directional ocean spectra were developed from the DPG data, and although no other in_ situ directional wave monitors were available for comparison, the directional peak determined from the DPG agreed well with simultaneous High Frequency (HF) radar data. The DPG instrument is about one-half the size and less than one-sixth the weight of conventional pressure sensor arrays. The field establishment of the orientation of directional-measuring instruments is also discussed.

Application of microwave spectroscopy for the detection of water fraction and water salinity in water/oil/gas pipe flow

The application of artificial neural networks to non-intrusive multi-phase metering

Uncertainty analysis of the high pressure closed loop gas flow standard facility in NIM

Summary A critical component of natural gas in organic-rich shales is adsorbed gas within organic matter. Quantification of adsorbed gas is essential for reliable estimates of gas-in-place in shale reservoirs. However, conventional high-pressure adsorption measurements for coal using the volumetric method are prone to error when applied to characterize sorption isotherm in shale gas systems due to limited adsorption capacity and finer pores of shale matrix. Innovative laboratory apparatus and measurement procedures have been developed to accurately determine the relatively small amount of adsorbed gas in a Marcellus shale sample. The custom-built volumetric apparatus is a differential unit composed of two identical single-sided units (one blank and one adsorption side) connected with a differential pressure transducer. The scale of the differential pressure transducer is ±50 psi, a hundred-fold smaller than the absolute pressure transducer measuring to 5,000 psi, leading to a significant increase in the accuracy of adsorption measurement. Methane adsorption isotherms on Marcellus shale are measured at 303, 313, 323, and 333 K with pressure up to 3,000 psi. In addition, a fugacity-based Dubinin-Astakhov (D-A) isotherm is implemented to correct for the nonideality and to predict the temperature dependence of supercritical gas sorption. The Marcellus shale studied generally displays linear correlations between adsorption capacity and pressure over the range of temperature and pressure investigated, indicating the presence of a solute gas component. It is noted that the condensed-phase gas storage exists as the adsorbed gas on the shale surface and dissolved gas in kerogen, where the solute gas amount is proportional to the partial pressure of that gas above the solution. One of the major findings of this work is the experimental observation of the contribution of dissolved gas to total gas storage. With adsorption potential being modeled by a temperature-dependence expression, the D-A isotherm can successfully describe supercritical gas sorption for shale at multiple temperatures. Adsorption capacity significantly decreases with temperature attributed to the isosteric heat of adsorption. Lastly, the broad applicability of the proposed fugacity-based D-A model is also tested for adsorption data provided in the literature for Woodford, Barnett, and Devonian shale. Overall, the fugacity-based D-A isotherm provides precise representations of the temperature-dependent gas adsorption on shales investigated in this work. The application of the proposed adsorption model allows predicting adsorption data at multiple temperatures based on the adsorption data collected at a single temperature. This study lays the foundation for an accurate evaluation of gas storage in shale.

Energy is transferred between the flowing blood and the vessel walls during pulsatile blood flow (a normal pulse cycle) resulting in storage and dissipation of elastic energy. This allows the elastic and muscular arteries to act as an auxiliary pump to propel the blood fluid forward during systole and maintain a basal blood pressure during diastole. The pulsatile flow pattern caused by the contraction of the left ventricle sets up a state of harmonic motion in the blood vessel walls throughout the arterial vasculature. In this paper, we report on a kinetic energy analysis of pressure and flow velocity waveforms, which characterize energy transfer between the blood and the blood vessel walls at different frequencies of pulsatile flow and pressure. Porcine carotid arteries were tested under simulated physiologic pulsatile flow and pressure conditions in a model water bath system and compared to measurements in vivo on human carotid arteries. Fluid and wall pressures were monitored on the porcine vessels in situ using an absolute differential pressure transducer (fluid) and by a low-pressure volumetric balloon transducer (wall), respectively. A continuous-wave Doppler ultrasonic transducer monitored flow velocity and measurements were made both in vitro and in vivo at frequencies of 1.2 Hz (72 cycles per minute) and 2.1 Hz (125 cycles per minute) for comparison purposes. The areas under the pressure versus time and flow velocity versus time curves were used to calculate the relative change in work and kinetic energies. The calculations of the ratios of the relaxation slopes versus the impact slopes showed that the vessel wall absorbed more energy at the frequency of 1.2 Hz than at the 2.1 Hz frequency. The results of these calculations indicate that energy of the pulse pressure at rest pulse rates is absorbed and dissipated in the vessel wall and the surrounding extracellular matrix. At higher pulse rates and pressures, the vessel wall becomes increasingly elastic, and therefore, transmits or reflects most of the energy of the pressure pulse back to the blood fluid. As the vessel wall becomes less compliant with aging or disease, the energy absorbing and dissipating properties of the arterial wall at rest pulse rate diminish.

This report presents the measured data and the analyses performed to date on the full-scale high-energy qualification and flow interruption gate valve testing to develop technical insights for the United States Nuclear Regulatory Commission (USNRC) effort regarding Generic Issue 87 (GI-87). The research was sponsored by the USNRC and conducted by researchers from the Idaho National Engineering Laboratory. We tested two 6-in., 900-lb class valve assemblies, which represent a significant percentage of the reactor water cleanup isolation valves installed in plant applications. These valves were modified before testing by adding a high temperature load cell in the valve stems, which allowed the direct measurement of valve stem thrust during both opening and closing valve cycles. Instrumentation installed in the flow loop and on the valve assemblies measured the important valve system test responses. Additionally, during the test program, all of the currently popular motor operated valve diagnostic test systems monitored the performance of the valves. Initially the valves were subjected to the hydraulic and leakage qualification tests defined in ANSI B 16.41 and then to flow interruption and reopening valve tests at boiling water reactor primary system water temperature and pressure conditions with downstream line break flows. For the two valves tested, results show that (a) the disc factor used in current industry motor operator sizing equations may require an additional term to account for nonlinear performance, (b) the thrusts required to close the valves were sensitive to the fluid temperature, and (c) the results of testing at lower pressures, temperatures, and flows cannot be extrapolated to design basis pressures, temperatures, and flows for valve designs that have not exhibited linear performance behavior during design basis prototypical testing. 2 refs., 30 figs., 4 tabs.

A signal processing technique is presented for determining the composition of multiphase oil-water-gas flow in a pipe using noninvasive ultrasonic speed of sound measurements from a transmitter-receiver pair bonded to diametrically opposite sides of a pipe. A linear chirp excitation is used to send broadband ultrasonic energy that propagates in two paths from transmitter to receiver such as: 1) a wave through the pipe wall and then the multiphase mixture and 2) ultrasonic guided waves along the pipe wall in the circumferential direction. As the ultrasonic attenuation of the multiphase mixture increases, the amplitude of the signal through the fluid mixture decreases relative to that of circumferential guided waves, making it difficult to determine the time of arrival of the fluid-path signal and, hence, the speed of sound in the mixture. The proposed signal processing technique overcomes this challenge by using: 1) a guided wave subtraction approach to suppress the strength of guided wave signals relative to the fluid-path signal and 2) a Gaussian reconstruction approach for synthetic enhancement of the fluid-path signal by output signal reconstruction at frequencies corresponding to peak transmission of ultrasonic energy. The efficacy of the technique is demonstrated using experiments carried out in a field-scale flow loop with varying compositions of oil-water-gas mixtures. It is shown that the proposed approach can enhance the signal detectability by approximately 20 dB in comparison with the traditional approach that does not utilize guided wave subtraction and also improves the gas tolerance of composition measurements up to 20% in gas volume fraction.

An Integrated Health Monitoring System for Fission Surface Power

Pressure measurements and convection velocity evaluations in two-phase flow

Nickel Alloy clad tubulars are increasingly used for riser applications where concerns about carbon steel integrity and life expectancy exist. Here galvanic corrosion is one of possible problems. The objective of this paper is to investigate the performance of corrosion inhibitor on the galvanic corrosion of Nickel Alloy and Carbon steel X65. Multiphase flow loop tests were conducted to evaluate the effect of incline angles, flowing conditions, and inhibitor performance on possible detrimental influence of galvanic coupling between carbon steel and Nickel Alloy. To determine the galvanic coupling effect, a series of pipe spool pieces made of Nickel Alloy and carbon steel X65 were used into the multiphase flow loop. The sections were made such that the interior exposed surface ratio was 10:1 (Nickel Alloy to X65 carbon steel). A commercial corrosion inhibitor was evaluated. Results showed that severe galvanic corrosion was observed on carbon steel pipe sections coupled with Nickel Alloy in the absence of inhibitors. The galvanic corrosion attack was significantly decreased on the carbon steel pipe sections with the presence of corrosion inhibitor.