Dynamic Fluid Loss Characteristics of Foam Fracturing Fluids

Abstract

Dynamic fluid-loss measurements were conducted on core samples ranging in permeability from 0.02 to 140 md to measure the effect of several parameters on the foam fluidloss coefficients. The parameters tested were core permeability, gel concentration in the liquid phase, foam quality, temperature, core length, and differential test pressure. Realistic fluid-loss coefficients are necessary for proper design of foam fracturing treatments.The type of foam used in most conventional fracturing treatments is a wall-building fluid. Although this foam has excellent inherent fluid-loss properties, the fluid-loss values reported in this paper resemble those of conventional fracturing fluids more closely than reported earlier. These values have been used in the successful design of field fracturing treatments.These data support the mechanism of two-phase flow in porous media suggested by Holm. 1 The fluid passing through the cores was rich in liquid phase with composition proportional to the viscosity of the liquid phase.The broad range of fluid-loss coefficients for foam calculated in these tests is intermediate in value to those reported in similar tests by Blauer and Kohlhaas,2 who obtained lower values, and King, 3 who obtained higher values.

Multi-Phase Fluid-Loss Properties and Return Permeability of Energized Fracturing Fluids

“…It also shows direct measurements of the ability of the gas component to leak-off into the invaded zone, thereby increasing the gas saturation around the fracture and enhancing the gas productivity during flowback. Our conclusions not only confirm, but add to the findings of for linear gels, and the findings of Harris (1985) for nitrogen foams. Tables Table 2.1: Rheology correlations for nitrogen foams (Reidenbach et al, 1986) …”

Multiphase Fluid-Loss Properties and Return Permeability of Energized Fracturing Fluids

“…Several papers (Harris 1985(Harris , 1987 and field observations (Grundman 1983) have acknowledged the superior fluid-loss properties of foams. However, very limited qualitative results have supported this claim.…”

“…We compared our N 2 foam leak-off data with the data published by Harris (1985) and by Penny, Conway and Lee (1985). These papers are the only known references on foam leak-off.…”

“…The leak-off data are included in Table 5.1 which contains four sections: (1) the total (liquid+gas) leak-off coefficient of guar-N 2 foams reported in this paper, (2) the leak-off coefficient of linear gels reported in this paper, (3) the total leak-off coefficient of HPG-N 2 foams reported by Harris (1985), and (4) the total leak-off coefficient of HPG-N 2 foams reported by Penny, Conway and Lee (1985). As mentioned earlier, a direct comparison with public data is cumbersome.…”

“…There is very little published data for foam leak-off and there are a multitude of parameters. The first set of data is taken from Table 1 in Harris (1985). The second set of data is taken from Figure 10 in Penny, Conway and Lee (1985).…”