MODELLING AND COMPUTATIONAL SOLUTION FOR THE CONTROL OF HYDROCARBON DEW POINT IN NATURAL GAS PRODUCED IN MATURE OIL WELL
JONAS L. M. da S. SANTOS1; ARIOSTON A. de MORAIS Jr1; Paulo Romero de Araújo Mariz1; Marcelo da S. Pedro1; LEOPOLDO O. A. ROJAS1
1 Universidade Federal da Paraíba
doi:10.20906/CPS/CILAMCE2017-1104
Resumo
Production of oil and gas from mature oil wells is an important activity nowadays. The low production per well (3-100 BPD), demands the use of nonconventional technologies. In order to use the associated gas, it must be treated to fit it into the ANP regulation. The hydrocarbon dew point (HDP) is one of the sensitive parameters to be control principally for security reasons. A multicomponent PSA process is proposed to control HDP for low gas production. In this context the modelling and simulation of a multicomponent adsorber is presented. The model includes the mass and heat balance equations, for the heterogeneous multicomponent system in a non- steady state. The mass inter-phase flux is calculated by the Langmuir extended isotherm, considering locally thermodynamics equilibrium. These system of partial differential equations were solved by finite difference method, using central difference for space discretization and backward difference for the discretization of time partial derivatives. The boundaries were introduced in the spatial ends. By this, the hole system is assumed to behave as an initial value problem. For the initial time all the space variables are known. The variables in the next step of time are calculated by solving the non-linear system taking into account the variables in the former time. A four component system of i-C4H10, CO2, C2H6 e CH4, were studied. The transient mass transfer and the adsorption and desorption processes were monitored. The heat balance revealed the temperature dependence in the adsorptive process. The model could predict the breakthrough curve for the four components. This model is proposed to be used as real time tool for optimizing the operation of the adsorption unit.
Palavras-chave: Adsorption; Dew Point; Hydrocarbon; Mature Oil Well