A recently proposed algorithm for performing thermodynamic equilibrium calculations subject to the influence of the gravitational field is extended to semicontinuous mixtures. The characterization of the continuous families is done by a pseudocomponent discretization based on a convenient choice of orthogonal polynomials to sample the distribution function interval. Then, adequate quadrature points and weights are calculated. We present results for a family of hydrocarbons from C-8 to C-20 with 51 mol % of methane for one-phase, two-phase, three-phase, and near-critical systems. Our results show the validity of the procedure for simulations of deep reservoirs and high-pressure storage conditions, solving problems with a high number of independent variables.