Computer implemented method for assessing the viability of fluid production from a hydrocarbon reservoir throughout facilities having a predetermined field architecture using characteristics of a target fluid within the hydrocarbon reservoir under uncertainty, the facilities include at least one pipe connecting a first point of extraction located within the reservoir and a final end point located at surface, the method comprising the following steps: a) establishing m predetermined fluid properties ( p 1, p 2,..., p m) comprising at least a first fluid property ( p 1) directed to one of the phases of the target fluid, either liquid or gas, and a second fluid property ( p 2) directed to the gas/liquid ratio of the target fluid, the two properties measured in the reservoir or estimated by a predicting model; b) assigning a probability density function ( f 1) for the first fluid property ( p 1) and a probability density function ( f 2) for the second fluid property ( p 2); c) providing m - 2 correlations c 3,..., c m dependent at least on p 1 and/or p 2 properties such that p i = c i ( p 1, p 2); i = 3,..., m; d) for each property p i, i = 3,..., m - generating, automatically by a computer system, r sample values c i ( p̃ 1, p̃ 2) wherein p̃ 1 is a random sample according to its probability density function f 1 and p̃ 2 is a random sample according to its probability density function f 2; - generating, automatically by a computer system, a probability density function f i for property p i from the r sample values c i ( p̃ 1, p̃ 2); e) based on the probability density functions ( f 1, f 2,..., f m) determining the characterizing properties p i, i = 1,..., m of the target fluid in the hydrocarbon reservoir; f) using the characterizing properties of the target fluid determined in step e), assessing the fluid production viability of the reservoir by simulating the evolution of the target fluid along the piping of the predetermined field architecture. a) establishing m predetermined fluid properties ( p 1, p 2,..., p m) comprising at least a first fluid property ( p 1) directed to one of the phases of the target fluid, either liquid or gas, and a second fluid property ( p 2) directed to the gas/liquid ratio of the target fluid, the two properties measured in the reservoir or estimated by a predicting model; b) assigning a probability density function ( f 1) for the first fluid property ( p 1) and a probability density function ( f 2) for the second fluid property ( p 2); c) providing m - 2 correlations c 3,..., c m dependent at least on p 1 and/or p 2 properties such that p i = c i ( p 1, p 2); i = 3,..., m; d) for each property p i, i = 3,..., m - generating, automatically by a computer system, r sample values c i ( p̃ 1, p̃ 2) wherein p̃ 1 is a random sample according to its probability density function f 1 and p̃ 2 is a random sample according to its probability density function f 2; - generating, automatically by a computer system, a probability density function f i for property p i from the r sample values c i ( p̃ 1, p̃ 2); - generating, automatically by a computer system, r sample values c i ( p̃ 1, p̃ 2) wherein p̃ 1 is a random sample according to its probability density function f 1 and p̃ 2 is a random sample according to its probability density function f 2; - generating, automatically by a computer system, a probability density function f i for property p i from the r sample values c i ( p̃ 1, p̃ 2); e) based on the probability density functions ( f 1, f 2,..., f m) determining the characterizing properties p i, i = 1,..., m of the target fluid in the hydrocarbon reservoir; f) using the characterizing properties of the target fluid determined in step e), assessing the fluid production viability of the reservoir by simulating the evolution of the target fluid along the piping of the predetermined field architecture.