For well stimulation

Polypropylene glycol, particulate hydrophobic silica, and a fatty acid methyl ester, or an olefin or linear paraffin as a liquid diluent, are proposed for well-stimulation jobs [357]. 

Crema, S.C. Aim, R.R. "Foaming of Anhydrous Methanol for Well Stimulation", SPE paper 13565, 1985 International Symposium on Oilfield and Geothermal Chemistry, Phoenix, April 9-11. 

Solutions of TKPP were mixed with aqueous fluids commonly encountered in drilling or completion of wells. Unlike saturated zinc bromide, concentrated TKPP solutions can be mixed in any proportion with fresh water with the only result being a decrease in solution density. Similar results were obtained with conventional oil field brines containing as much as 400 parts per million polyvalent cations, mostly calcium. Saturated solutions of calcium hydroxide also can be added to TKPP in any proportion without promoting precipitation as can concentrated hydrochloric acid solutions, conventionally used for well stimulation. The acid tends to generate a slight haze as the pH is reduced from 11.5 to approximately 8 however, this haze rapidly disappears as the pH is lowered by further addition of acid. 

History-Explosive Fracturing for Well Stimulation", ProeSpring Meeting Mid-Continent District, Div-Production, API, Wichita, Kansas, April 8-10, 1970, pp 58-63 2)G.Cohn, Edit, Expls Pyrots 5(6), 1972 (Abstract)... 

The N2 used for well stimulation is transported to the well as a liquid in a cryogenic transport tank. The tank that contains the N2 is kept at a temperature of —196 °C and a pressure of 30 kPa. The liquid N2 is pumped with a cryogenic positive displacement pump into a heat exchanger where it is transformed from a liquid into a gas by raising the temperature (Figure 3). The dry gas is pumped into the liquid or slurry treatment line downstream from the liquid pumpers. At this point, the N2 is commingled with the treating fluid and creates a foam that is pumped downhole. 

Suspensions or slurries used for well stimulation are prepared by adding a known quantity of proppant to the carrier fluid of choice to obtain a desired proppant concentration. The proppant concentration is usually referred to as the amount of solids added in a gallon of carrier fluid. A 20-40 U.S. mesh size is the most commonly used proppant for hydraulic fracturing. However, other particle sizes such as 8-12, 8-16, 10-20, 12-20, and 40-60 mesh are also used. 

Chambers, D.J. (1994) Foams for well stimulation, in Foams, Fundamentals and Applications in the Petroleum Industry (ed L.L. Schramm), American Chemical Society, Washington, DC, pp. 355-404. 

API RP 42 API recommended practices for laboratory testing of surface-active agents for well stimulation, American Petroleum Institute, 2nd Edition, 1977, 6—8. 

Smith, S.A. (1989) Manual of Hydraulic Fracturing for Well Stimulation and Geologic Studies. National Groundwater Association. 

API, Recommended Practices for Laboratory Evaluation of Siuface Active Agents for Well Stimulation, API Recommended Practice 42, 2nd edn, Reaflrrmed February 1992. 

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