         Ks   = this.porousMedia.Ks;
            <span class="comment">% Get the fluids bulk modulus</span>
            Klb  = this.liquidFluid.K;
            Kgb  = this.gasFluid.K;
            <span class="comment">% Gas saturation degree</span>
            Sg   = 1.0 - Sl;
            <span class="comment">% Capillary pressure</span>
            pc = pg - pl;
            <span class="comment">% Derivative of the liquid saturation degree wrt pc</span>
            dSldpc = this.capillaryPressure.derivative