Flow tests

Some additives have the ability to lower the pour point without lowering the cloud point. A number of laboratory scale flow tests have been developed to provide a better prediction of cold temperature operability. They include the cold filter plugging point (CFPP), used primarily in Europe, and the low temperature flow test (LTFT), used primarily in the United States. Both tests measure flow through filter materials under controlled conditions of temperature, pressure, etc, and are better predictors of cold temperature performance than either cloud or pour point for addithed fuels. 

As of this writing, it has not been possible to use the seismic data which defines the volume of the reservoir to also determine the joint stmcture. Extended flow testing is the most direct measure of the efficiency and sustainabiUty of energy recovery from the reservoir. The use of chemical tracers in the circulating fluid can also provide valuable supporting data with regard to the multiplicity of flow paths and the transit time of fluid within the reservoir (37). 

Fig. 12. HDR reservoir flow test at Fenton Hill, New Mexico (1992) (39). (a) Injection pressure profile ( ) and a sismic limit (-------) (b) injection ( )...

N. E. V. Rodrigues, B. A. Robinson, and E. Counce, "Tracer Experiment Results During the Long-Term Flow Test of the Fenton Hill Reservoir", Proceedings of the Eighteenth Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, Calif., 1994, in press. 

D. W. Brown and R. DuTeau, "Progress Report on the Long-Term Flow Testing of the HDR Reservoir at Fenton Hill, New Mexico", in Ref. 37. 

Existing facihties present daily bulk soflds flow problems soflds flow testing and analysis saves many hours of expensive downtime and thousands of dollars, thus moving from the complication of quick-fix solutions that are not satisfactory, to proven engineering solutions that work every time. 

The so-called flow temperature cannot be considered to be either the processing temperature or the maximum service temperature. It is obtained using the highly arbitrary Rossi-Peakes flow test (BS 1524) and is the temperature at which the compound is forced down a capillary of fixed dimensions by a fixed load at a specified rate. It is thus of use only for comparison and for quality control purposes. Since the rates of shear and temperatures used in processing are vastly different from those used in this test, extreme caution should be taken when assessing the result of flow temperature tests. 

There is no entirely satisfactory way of measuring flow. In the BS 2782 flow cup test an amount of moulding powder is added to the mould to provide between 2 and 2.5 g of flash. The press is closed at a fixed initial rate and at a fixed temperature and pressure. The time between the onset of recorded pressure and the cessation of flash (i.e. the time at which the mould has closed) is noted. This time is thus the time required to move a given mass of material a fixed distance and is thus a measure of viscosity. It is not a measure of the time available for flow. This property, or rather the more important length of flow or extent of flow, must be measured by some other device such as the flow disc or by the Rossi-Peakes flow test, neither of which are entirely satisfactory. Cup flow times are normally of the order of 10-25 seconds if measured by the BS specification. Moulding powders are frequently classified as being of stiff flow if the cup flow time exceeds 20 seconds, medium flow for times of 13-19 seconds and soft flow or free flow if under 12 seconds. 

For flow tested combinations, see a few typical data in Table 7-12. Note, for example, that using a Continental disk reverse acting knife blade rupture disc with a Crosby JOS/JBS pressure relief valve that the combined effect is to multiply the rated capacity of the Crosby valve by a multiplier of 0.985 for a set pressure in the 60-74 psig range... 

Large Scale Rubber Cement High Viscosity Tw o-Phase Flow Test Report, DIERS/AIChE, 1986, 114 pages. 

Turndovn is usually limited to 0.5 1, and liquid distribution can be poor if the sprays are not carefully laid out and the system flow tested for uniformity. Another problem is misting of the liquid from the sprays and the resulting entrainment out of the tower or up to overhead mist eliminators. 

Large Scale Polystyrene-Ethylbenzene High Viscosity Two-Phase Flow Test Report. DIERS/AlChE, 1986, 76 pages. 

There are various testing procedures, such as the Warren Spring Rotating Flask test (WSL test, Labofina test). Institute Francais du Petrole flow test (IFF test), Mackay-Nadeau-Steelman test (MNS test), EXDET, and other procedures. 

Model cycling of the first column in the purification stream (this usually is subjected to the harshest cleaning conditions and sees the dirtiest feedstocks), process monitoring of production columns (yield and purity of product, HETP measurements, pressure-vs.-flow tests)... 

Static(batch) and dynamic(flow) tests were carried out on toluene - extracted and peroxide - treated Wilmington oil field unconsolidated sands with dilute solutions of polyacrylamide (Dow Pusher-500) polymer in 1 wt% NaCl at 50° C and 1.5 ft./day, simulating reservoir temperature and flow rates. In the static tests, Ottawa sand, with particle size distributions similar to the Wilmington sand, were also used for comparison purposes. 

Flow Tests. One foot long sand packs using Wilmington oil field unconsolidated sand were prepared for each of the flow tests. Porosity and permeability of all the sand packs were within 30-35% and 100-300 md, respectively. All core packs were evacuated to about 1 mm of mercury (Hg) before saturating them under gravity to assure complete water saturation. Table III gives the core and fluid properties for the flow tests. The properties of the cores were chosen so that they are close to the field conditions reported by Krebs(15). 

Flow Tests. Results of the flow tests are shown in Figures 3 through 6. Figure 3 shows the results of a typical run with a brine saturated sand pack wherein a 300 ppm polymer solution in 1 wt% NaCl was injected at a pH of 8.26. Before this, steady state conditions were established in the core by injecting 1 wt% NaCl. The pH values were stabilized at 8.0 and viscosity at around 1.1 cp. The pressure drop across the core stayed constant up to about 8 PV of polymer injection, the pH stayed in the acidic range, and effluent viscosity was consistently lower than the influent value. At about 8 PV the pressure drop started to build and within 2 PV, increased up to about 100 psi essentially plugging the core. No polymer was eluted until the end of the run. 

The retention was much higher in the static tests compared to the flow tests. This is partly due to the inaccessibility of the smaller pores by the polymer... 

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