How to ensure the quality of raw materials oil fracturing proppant fracturing fluid

Test fracturing fluid components before the job is to ensure that the only method used by the fracture stimulation fluid has the expected performance. On water-based fracturing fluid, the mixed water must meet defined specifications. The water should be mixed with substantially no free iron relative state (<25mg / LF min +), and sadness can promote or catalyze peroxy gel degradation bisulfate (persulfate) Other reducing agents breaker reaction (Ely, 1985). Mixed water pH on the hydration rate of the polymer. If the pH of the mixed water is low, may be faster hydration, and the formation of gel. If the mixing water pH is too high, the gel hydration very slowly. Water temperature also affects the rate of hydration, the water temperature can be increased to accelerate the rate of hydration of polymer (viscosity increase). Frac tank with water to make a linear (pre-crosslinked) gel polymer samples required site. Through testing, field use to ensure proper dispersion and hydration (increase in viscosity) good gel.
If it reaches the appropriate viscosity, can evaluate the performance of cross-linking agent. hydraulic fracturing  sample containing the appropriate concentration of the crosslinking agent is heated to accelerate the crosslinking and form a thick gel. In addition to the requirements of the overall performance of the gel, the gel time should be required for crosslinking (crosslinking time) measurements. Crosslinking time measuring common field test method is a vortex closed test, the static hardness testing (Hodge and Baranet.1987) and the use of a falling ball viscometer (Cawiezel and Elbel.1990). Vortex closure test method is to stir the polymer solution in the blender to form a vortex. Then adding the crosslinking agent, the time required to close the vortex, i.e., the time required for the formation of a calm surface, called the vortex closure time. Hardness test is a static liquid components were mixed together, and then back and forth between the two containers perfusion. (Like lumps appear in between the fibers or when the vessel perfusion) when the liquid looks very thick, is the cross-linking time. With the falling ball viscometer crosslinked liquid gradually showing the time required for the suspension characteristics. Hodge and Baranet (1987) noted that the eddy current testing closed and static hardness tests are often inaccurate, because the test does not simulate the liquid in the pipe is exposed to heat or shearing action occurring in the wellbore. Both of these factors greatly affect the crosslinking rate and viscosity growth. As discussed in the results of the 761, the use of double cross-linking system does not accurately control crosslinking time.
Not all mixing water or fracturing fluid additives are compatible. When using the site materials preparation of test samples, should include all components. Preferably before the laboratory work and before adjustment by testing various materials found serious problems exist in terms of compatibility. To determine the fracturing fluid performance at elevated temperatures of how often used Fann 50 rheometer test liquid properties, initial testing should reveal problems associated with chemical agents, or issues related to the mixing water or oil source.
Once mixed liquid, i.e., any time to monitor any continuous mixing linear gel viscosity, and it is determined that the problem is likely to arise. In addition, the crosslinked fluid sample should be checked periodically. Ely (1985) gives a detailed discussion of the quality assurance process.