Pressure history

Of all the piezoelectric crystals that are available for use as shock-wave transducers, the two that have received the most attention are x-cut quartz and lithium-niobate crystals (Graham and Reed, 1978). They are the most accurately characterized stress-wave transducers available for stresses up to 4 GPa and 1.8 GPa, respectively, and they are widely used within their stress ranges. They are relatively simple, accurate gauges which require a minimum of data analysis to arrive at the observed pressure history. They are used in a thick gauge mode, in which the shock wave coming through the specimen is... 

One of the most interesting results of the zinc ferrite synthesis is the observation that the yield of the product is dependent on the early pressure history. This behavior is shown in Fig. 8.3, which plots the yield versus temperature for baratol explosive loading and for Composition B explosive loading. The difference between these loadings is that the initial pressure pulse amplitude is significantly greater with Composition B. Apparently, the early pressure history has an important conditioning effect for subsequent reactions. 

The bottom part of Figure 8.4.5 illustrates the pressure histories associated with the transition to detonation events in an unobstructed channel ... 

Apparatus. A constant rate displacement pump charged with mercury was used to displace the fluid of interest from steel cylinders to the core. A pressure transducer connected to the chart recorder provided the pressure history of each core flood. An automatic sampler with... 

Matrix acidizing treatments are more often performed, nowadays, with sensors and data acquisition systems continuously recording the surface pressure and rate histories. According to a recently proposed methodology (15), these records can be used to compute downhole rate and pressure evolutions. The bottomhole pressure history is then compared to the theoretical response of an equivalent reservoir wherein a non-reactive fluid would have been injected according to an identical rate schedule. Following this method, the difference between both theoretical and actual pressure responses originates from the evolution of the skin of the true reservoir under the influence of the acid attack. Equation 1 is then used to derive the skin decrease from this pressure difference. 

Then, 11 m3 (70 barrels) of 15 /, HC1 were pumped downhole through a coil tubing. The bottomhole pressure history is in this case precisely derived from surface data, since the latter are collected in the open annular space between the coil tubing and the casing. No computation of friction pressure drops all along the injection string is needed, which removes a major source of errors in the derivation of bottomhole data. The bottomhole pressure is just equal to the sum of the surface... 

The maximum pressure increase due to desired and undesired reactions is, in practice, often investigated in laboratory equipment such as the ARC, RSST, and VSP (see Chapter 2, and Section 3.3 below) to verify the results from the mass balance. These test show the pressure history for a set of extreme conditions and, therefore, provide an estimate for gas production which can be used in scale-up calculations. Limitations in the applications of such tests may occur because of the test size relative to the plant scale. These aspects are discussed in Section 3.3.4. Such tests must be carried out for the complete range of temperatures which may occur on the plant scale. 

The data required for the emergency vent design includes [191] (1) the thermokinetic and pressure history monitored under near adiabatic conditions, (2) the character of the type of vented system (vapor, gassy, or hybrid), (3) the phase of the vented material (vapor, liquid, or two-phase), and (4) the degree of two-phase disengagement (turbulent, bubbly, or homogeneous). To determine these characteristics, the VSP defines the system as viscous (100 cp) or nonviscous, and also whether or not it has a foaming tendency. 

Intermittent loss of control was observed in the high output cases with only marginally effective pulsed fuel injection. Figure 21.14 shows the pressure history... 

Anticholinergic properties Maprotiline should be administered with caution in patients with increased intraocular pressure, history of urinary retention, or history of narrow-angle glaucoma because of the drug s anticholinergic properties. 

The above P-T-t paths do not cover all temperature-pressure histories. For example, all deep-seated rocks may be brought up rapidly by volcanic eruptions as xenoliths and hence may cool from a high temperature to room temperature rapidly. Furthermore, through drilling it is possible to obtain samples at high temperatures and pressures. 

Figure 1-18 Schematic temperature-pressure history (volcanic, ...

Fluid Properties from Production—Pressure History... 

Figure 9-1 gives production pressure history data for a typical black oil reservoir. The reservoir in this case does not have a gas cap and is not connected to an aquifer. The conventional method of plotting these data is against time. However, the trends we want to see are more apparent when the data are plotted against cumulative production, as in Figure 9-2. 

Fig. 9-1. Production-pressure history of a black oil plotted against time.

Fig. 9-2. Production-pressure history of Figure 9-1 plotted against cumulative oil production.

Fluid Properties from Production-Pressure History 249... 

Fig 22 Typical Impact-Face Pressure Histories Measured with Quartz Gauges... 

Figure 9.31 Comparison between experimental and FEM-CVA predicted pressure history at three pressure transducer locations. [18].

Applying equation (3) to the gas in the chamber, we have dp/dt = (dp/dt)/a. By substituting this relation into the one preceding it, differentiating, and then substituting the result into the first expression, we find that the pressure history is described by... 

In Figure 2, dimensionless pressure histories of N2 and O2 at the same temperature and pressure condition were shown and they were compared with prediction results by Brandani model (Brandani, 1998). The values of D/r were obtained by nonlinear regression using the least-square method. 

Figum 2. Comparisons of axpartnenai dimensionless pressure histories and the prediced results by Brandani modal at the caes of N, and Ot adsorptions. 

Figure 1 Flowsheet of hybrid membrane-PSA process. Steps pressurization (PR = PRi + PR2). high-pressure adsorption (HPA), co- and counter-current blowdown (CD, BD), Purge (PG) A stream enriched in less adsorbed component, B-. stream enriched in strongly adsorbed component. Pressure histories of the integrated cycle at CSS.

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