Foamed fracturing fluids

P. C. Harris and S. J. Heath. High-quality foam fracturing fluids. In Proceedings Volume, pages 265-273. SPE Gas Technol Symp (Calgary, Canada, 4/28-5/1), 1996. 

Reidenbach, V.G. Harris, P.C. Lee, Y.N. Lord, D.L. "Rheological Study of Foam Fracturing Fluids Using Nitrogen and Carbon Dioxide", SPE paper 12026, 1983 SPE Annual Technical Conference and Exhibition, San Francisco, October 5-8. 

Harris, P.C. "Dynamic Fluid Loss Characteristics of C02 Foam Fracturing Fluids," SPE Prod. Eng.. 1987, 2(2), 89... 

Harris, P.C. A Comparison of Mixed Gas Foams With N2 and C02 Foam Fracturing Fluids on a Flow Loop Viscometer in Proc., Annual Technical Conference of SPE Society of Petroleum Engineers New Orleans, LA,... 

Watkins, E.K. WendorffC.L. Ainley, B.R. A New Crosslinked Foamed Fracturing Fluid in Proc., Annual Technical Conference of SPE, Society of Petroleum Engineers Richardson, TX, 1983, paper SPE 12027. 

Cocamidopropyl betaine and cocamidopropyl hydroxysultaine, discussed later, are also used in petroleum production. Their relatively high foaming nature, electrolyte tolerance and hydrolytic stability make them useful for foam acidizing and foam fracturing fluids. 

Desirable foams Foam drilling fluid Foam fracturing fluid Foam acidizing fluid Blocking and diverting foams Gas-mobility control foams... 

Foamed Fluids. N2 has been used in oil field stimulation work since 1961. In the mid 1970s, foamed fracturing fluid using N2 was developed. More recent uses of N2 foams in well stimulation involve well clean-outs and treatment diversions. 

Where k is the permeability of reservoir rock to foam fracture fluid, AP is the differential pressure, is porosity, and fi is the viscosity of the foam fluid. 

Investigations to determine the leak-off control mechanisms of foam have shown (26—29) that the effective permeability of a porous medium is greatly reduced in the presence of foam. Some basic assumptions were used during the testing to determine the leak-off control mechanisms of foamed fracturing fluids. The first assumption was that the liquid or continuous phase moves freely, and permeability reduction is a function of the liquid saturation. The other assumption was that the gas or discontinuous phase flows only by rupture and reformation of the foam film. The resistance of foam to flow through porous media is a function of the stability of the foam. 

Phillips, A. M. Couchman, D. D. High Temperature Rheology of C02 Foam Fracturing Fluids Southwestern Petroleum Short Course Western Company of North America, 1987. 

The features of foam application in petroleum industry were summarised by Schramm [224], Thereafter only very few publications appeared on this subject, so that we mainly describe Schramm s concepts. First of all, these are foams which contribute to an enhanced efficiency of oil recovery foam drilling fluids, foam fracturing fluids, gas mobility control foams, and foam acidising fluids. 

Harris, PC. (1990) A comparison of mixed gas foams with n2 and c02 foam fracturing fluids on a flow loop... 

Gas/Liquid Systems Producing oilwell and well-head foams Oil flotation process froth Distillation and fractionation tower foams Fuel oil and jet fuel tank (truck) foams Foam drilling fluid Foam fracturing fluid Foam acidizing fluid Blocking and diverting foams Gas-mobility control foams... 

Low surface tension foam fracturing fluid performance evaluation... 

Foam was completely different from gel fracturing fluid. Foam fracturing fluid could not be measured as gel fracturing fluid criterion such as temperature resistance property, shear resistance property, conductivity property, etc. Other properties of foam fracturing fluid were evaluated by interior experiment. Foam fracturing fluid formulations were the mass fraction of 0.3% fluorocarbon surfactant AS-3, the mass fraction of 0.4% viscoelastic surfactant VES-A as a foam stabilizer, 0.5% DW clay stabilizer and water. 

Determine the specific relationship between shear rate impacted on foam fracturing fluid and viscosity. Foam fracturing fluid was a typical shear thinning fluid. 

Figure 3 shows that, at 30° C, foam fracturing fluid still retained higher viscosity retention after lOmin at 170s shear. Foam fluid was Bingham fluid. 

Rheometer was used to test foam fracturing fluid dynamic mechanical, primarily included given frequency stability variable shear stress and constant shear stress variable frequency determination. 

Figure 3. The releationship between the apparent viscosity and the shear rate to foam fracturing fluid. 

Figure 4. The rheological curves of the foam fracturing fluid.

Foam fracturing fluid carrying sand performance... 

Foam fracturing fluid could improve sand ratio to ensure that fracturing fluid to carry proppant into the far-reaching cracks, thereby effectively increased the fracture conductivity. 

Foam fracturing fluid core damage experiment... 

Fluorocarbon foaming agent used in foam fracturing fluid effectively reduces the surface tension which is conduciveto flowback. 

The foam fracturing fluid system is easily compounded, so it is for dry-land unconventional reservoirs massive fracturing. 

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