Tests, laboratory

There are two types of laboratory tests toxicity determinations on wildlife and aquatic organisms and the use of model ecosystems to measure bioaccumulation and transport of toxicants and their degradation products. 

Similar tests can be carried out with aquatic organisms (e.g., the LC50 for freshwater fish such as rainbow trout and bluegills), the LC50 for estuarine and marine organisms, the LC50 for invertebrates such as Daphnia, and the effect of chemicals on the early stages of fish and various invertebrates. 

In this section, the relevant laboratory tests that should be carried out on polymers in support of a proposed polymer pilot will be described. Virtually all of the actual technical points concerning polymer properties—such as compatibility/stability, filterability and formation plugging, polymer solution preparation, adsorption in porous media, in-situ rheology—have been discussed in detail elsewhere in this book. However, earlier the objective was to present an explanation and a view on the science of the various phenomena involved in polymer physics and chemistry both in bulk solution and in flow through porous media. Here, the intention is to abstract the much more limited subset of experiments that should be carried out in support of a practical polymer flood application in the field. In all of the discussion below, it is assumed that a range of commercially available off-the-shelf polymers 

Before discussing the issues concerning the polymer experimental procedures, it is necessary to establish the conditions under which the more traditional field core data have been gathered (i.e. core permeabilities, relative permeabilities, etc.). Central to such consideration is the matter of core wettability and how the core has been conditioned or restored for the relative permeability experiments and, therefore, for the polymer flooding experiments. This very important matter will not be considered here, but it will be assumed that the wettability and conditioning of the reservoir core have been satisfactorily achieved. This is important for polymer properties, since the adsorption is thought to be greater in water-wet cores than in oil-wet systems. In the discussion below, it will be assumed in all cases that experiments in porous media use correctly conditioned field cores at residual oil (unless otherwise stated). The oil will be the (dead) field oil, and conditions of reservoir temperature, but not necessarily pressure, will be established in the core. 

There are basically three types of laboratory experiment that may be carried out on candidate polymer solution(s), injection brine and field core combinations. These involve polymer compatibility and screening, the generation of polymer core flood data and polymer/oil displacement experiments. Each type of experiment serves a different function as follows. 

The compatibility/screening tests are, in a sense, prerequisites for a polymer solution to be selected and involve polymer/brine compatibility, filterability, sensitivity to other additives, etc. If a given polymer, or polymer type, fails such screening tests, then it should be excluded from the candidate polymer list unless there is a simple technical solution which remedies the problem. The polymer core flood data are essentially the information that is collected in the laboratory that may be used directly (or indirectly) in the polymer simulations to assess the viability of the polymer pilot flood. Information such as concentration/viscosity behaviour, adsorption/retention levels, degree of permeability reduction, and in-situ rheology would come under this category. The importance of controlling the exact experimental conditions under which this type of data is collected will be discussed below. The third type of experiment relates to the oil displacement efficiency of the polymer solution and is usually only carried out in short linear systems. This type of experiment is of somewhat limited value for the reasons discussed below. 

Compatibility/screening of polymer. As indicated in the previous paragraph, this type of test relates to the selection of the most appropriate type of polymer for a given application. Even within a given class, for example HPAMs, some further selection is possible relating to properties such as molecular weight and degree of hydrolysis as well the actual form in which the polymer is supplied, e.g. emulsion, broth, gel or powder. It is essential 

Equipment to test the filtration characteristics of slurries in the laboratory is usually small, compact and fairly easy to construct. It is, therefore, well worth the constructional effort to enable the characterisation of slurries which are being, or will be, filtered on a larger industrial scale. Most of these tests are conducted at constant pressure and the data analysis has been introduced already in Section 2.5.1. 

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David, P G.l. Brown and E.W. Lehman (1993), SFPP - A new laboratory test for assessment of low temperature operability of modern diesel fuels". CEC 4th International Symposium, Birmingham. 

If oil and water are mixed as an emulsion, dehydration becomes much more difficult. Emulsions can form as oil-in-water or water-in-oil if mixed production streams are subjected to severe turbulence, as might occur in front of perforations in the borehole. Emulsions can be encouraged to break (or destabilise) using chemicals, heat or just gentle agitation. Chemical destabilisation is the most common method and laboratory tests would normally be conducted to determine the most suitable combination of chemicals. 

Possible water sources for injection are sea water, fresh surface water, produced water or aquifer water (not from the producing reservoir). Once it has been established that there is enough water to meet demand (not an issue in the case of sea water), it is important to determine what type of treatment is required to make the water suitable for injection. This is investigated by performing laboratory tests on representative water samples. 

Laboratory tests indicated that gamma radiation treatment and cross-linking using triaHylcyanurate or acetylene produced a flexible recycled plastic from mixtures of polyethylene, polypropylene, general-purpose polystyrene, and high impact grade PS (62). 

In laboratory tests, appHcation of DMAC to the skin of pregnant rats has caused fetal deaths when the dosages were close to the lethal dose level for the mother. Embryonal malformations have been observed at dose levels 20% of the lethal dose and higher. However, when male and female rats were exposed to mean DMAC concentrations of 31,101, and 291 ppm for 6 h per day over several weeks, no reproductive effects were observed (6). 

Health and Safety Factors. Boron trifluoride is primarily a pulmonary irritant. The toxicity of the gas to humans has not been reported (58), but laboratory tests on animals gave results ranging from an increased pneumonitis to death. The TLV is 1 ppm (59,60). Inhalation toxicity studies in rats have shown that exposure to BF at 17 mg/m resulted in renal toxicity, whereas exposure at 6 mg/m did not result in a toxic response (61). Prolonged inhalation produced dental fluorosis (62). High concentrations bum the skin similarly to acids such as HBF and, if the skin is subject to prolonged exposure, the treatment should be the same as for fluoride exposure and hypocalcemia. No chronic effects have been observed in workers exposed to small quantities of the gas at frequent intervals over a period of years. 

Flammability. The results of small-scale laboratory tests of plastic foams have been recognized as not predictive of their tme behavior in other fire situations (205). Work aimed at developing tests to evaluate the performance of plastic foams in actual fire situations continues. All plastic foams are combustible, some burning more readily than others when exposed to fire. Some additives (131,135), when added in small quantities to the polymer, markedly improve the behavior of the foam in the presence of small fire sources. Plastic foams must be used properly following the manufacturers recommendations and any appHcable regulations. 

Miscellaneous chemicals are used to modify the final properties of rigid polyurethane foams. Eor example, halogenated materials are used for flammabihty reduction, diols may be added for toughness or flexibiUty, and terephthalate-based polyester polyols may be used for decreased flammabiUty and smoke generation. Measurements of flammabihty and smoke characteristics are made with laboratory tests and do not necessarily reflect the effects of foams in actual fire situations. 

A number of laboratory tests are used to predict chemical stabihty. The amount of existent gum in a gasoline is determined by ASTM D381. This method involves evaporating a sample by a jet of heated air. The residue is weighed, solubles are extracted with / -heptane, and the sample is reweighed. 

Most hafnium compounds requite no special safety precautions because hafnium is nontoxic under normal exposure. Acidic compounds such as hafnium tetrachloride hydroly2e easily to form strongly acidic solutions and to release hydrogen chloride fumes, and these compounds must be handled properly. Whereas laboratory tests in which soluble hafnium compounds were injected into animals did show toxicity, feeding test results indicated essentially no toxicity when hafnium compounds were taken orally (33,34). 

Test salons are often used to evaluate hair fixatives. Half-head studies are performed, with the test product appHed to one side of the head and a control product to the other in reaHstic use amounts. Similar properties as desctibed in laboratory tests are measured. Finished products are often sent to testers homes where they have an opportunity to evaluate the products in real use situations for extended pedods. 

Thus the Brinell test in its original manifestation is a laboratory test in which cut pieces are brought to it for testing. The lack of portabiUty spawned several modifications to achieve that property. 

Quality Control and Testing. Control of inks is done by examining their color strength, hue, tack, rheology, drying rate, stabiHty, and product resistance. Elaborate control equipment and laboratory testing procedures are employed to test the finished inks. Weather-Ometers,... 

The sound-absorbing properties of acoustical materials also are influenced by the manner in which the materials are mounted. Standard mounting methods for use in laboratory testing are specified in ASTM E795-92 (2). Unless noted otherwise, pubflshed data for acoustic ceiling materials are for Mounting Type E-400, for which the material being tested is suspended 400 mm below a hard surface. 

L bor toiyMethods. The laboratory test method for determining the sound-transmission loss performance of constmctions is defined in ASTM E90-90 (11). The sample is installed in an opening between two highly reverberant rooms that are acoustically well isolated from each other. 

Elame-spread and smoke-density values, and the less often reported fuel-contributed semiquantitive results of the ASTM E84 test and the limited oxygen index (LOI) laboratory test, are more often used to compare fire performance of ceUular plastics. AH building codes requite that ceUular plastics be protected by inner or outer sheathings or be housed in systems aH with a specified minimum total fire resistance. Absolute incombustibHity cannot be attained in practice and often is not requited. The system approach to protecting the more combustible materials affords adequate safety in the buildings by aHowing the occupant sufficient time to evacuate before combustion of the protected ceUular plastic. 

Effectiveness of these EP oils can be evaluated by a number of laboratory test units such as those shown in Figure 4. While the American Society for Testing and Materials (ASTM) procedures describe a number of standard test procedures (10), the operating conditions and test specimen materials should be chosen to simulate as nearly as possible those in an appHcation. 

Resistance is iadicated by yes, ie, laboratory tests have shown enough promise to warrant test under actual service conditions. 

Sohd materials, such as gilsonite and asphalt, and partially soluble sulfonated asphalt may also be added to plug small fractures in exposed shale surfaces and thereby limit water entry into the formation (105,124). The asphalts are oxidized or treated to impart partial solubiUty. These materials may be softened by the downhole temperature, causing them to deform and squeeze into small openings exposed to the borehole. Laboratory tests designed to evaluate shale-stabilizing muds have confirmed the beneficial action of these materials (125) (see also Soil STABILIZATION). 

An alternative to this process is low (<10 N/m (10 dynes /cm)) tension polymer flooding where lower concentrations of surfactant are used compared to micellar polymer flooding. Chemical adsorption is reduced compared to micellar polymer flooding. Increases in oil production compared to waterflooding have been observed in laboratory tests. The physical chemistry of this process has been reviewed (247). Among the surfactants used in this process are alcohol propoxyethoxy sulfonates, the stmcture of which can be adjusted to the salinity of the injection water (248). 

Uniform, rehable flow of bulk soflds can allow the production of quaUty products with a minimum of waste, control dust and noise, and extend the hfe of a plant and maximi2e its productivity and output. By conducting laboratory tests and utili2ing experts with experience in applying soflds flow data, plant start-up delays that can impact schedule and cost can be eliminated. 

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