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fax 01-972-952-9435. AbstractWe have constructed new approximate analytical solutions for injection and falloff pressure response which include thermal effects that arise when flooding a reservoir with water having a temperature considerably below of that of the reservoir. We have developed an optimization code based on the Levenberg-Marquardt algorithm and coupled it with our new approximate analytical solutions to obtain a procedure for data analysis where our approximate analytical solutions are used as the forward model in the non-linear regression. We demonstrate that we can generate estimates of absolute permeabilities, the well skin factor, the length of the well and relative premeabilities by matching data to analytical solutions by minimization of a weighted least squares objective function. The relative permeability curves are constructed assuming a power law parametrization. In the horizontal well case, we show that the absolute permeabilities in the three principal directions can be resolved separately provided the duration of the test is sufficiently long.

Using the WKB approximation for the evaluation of penetrabilities at stellar energies, the D(d, p)T and D(d, n) 3 He total cross-sections are analysed in the energy range 0-100 keV (c.m.). The s and p wave contributions are extracted in each of these reactions. The branching ratios calculated from this partial wave decomposition are in good agreement with the experimental values deduced from muon catalyzed fusion and with those calculated from R-matrix theory. The screening effect is studied and the U 0 electron screening potential discussed. Theexperimental data for the D(d, d)D, D(d, p)T and D(d, n) 3 He reactions in the energy range 0-10 MeV have been analysed using R-matrix theory and the essential results concerning the parameters of levels in 4 He are reported in refs. [1, 2] whereas the R-matrix fits for the S(E) astrophysical factors of the D(d, p)T and D(d, n) 3 He reactions are shown in refs. [3, 4]. At stellar energies, the recently published data are those of Brown et al. [4], Krauss et al. [5] and Greife et al. [6]. The R-matrix analysis of Hale [2, 3] confirms the predominant influence of p-waves at low energies. On the other hand, the study of muon catalyzed fusion [7,8] has permitted to measure near zero energy the branching ratios for s and p waves in the D(d, p)T and D(d, n) 3 He reactions, respectively. An unexpected result is the higher value for the p-wave ratio giving 1.39±0.04 [7]. Finally, an R-matrix parametrization of low-energy transfer reactions has been recently developed [9] and applied to the D(d, p)T and D(d, n) 3 He reactions at energies up to 5 MeV to generate the astrophysical factor for bare nuclei and to analyse electron screening effects.In this work, we report the results of a WKB analysis of penetrabilities and some derived functions in the energy range 0-100 keV and extract the s and p waves contributions and the branching ratios. We also discuss the screening effects.At very low energies, the penetrabilities P L (E) for the s or p waves in the d + d interaction channel defined in the R-matrix formalism [10] can be expressed, following the WKB approxc EDP Sciences a. boughrara et al.: branching ratios and screening effect etc.