Numerical Simulation Of The Sulfur Particle Migration And Deposition In Gas Reservoir With High H₂S Content

In recent years, some gas reservoirs with high H₂S content have been found in northeast of Sichuan Province in China, such as LuoJiaZhai gas field and PuGuang gas field. Gas reservoir with high H₂S content contains a great quantity of hydrogen sulfide. Hydrogen sulfide is a kind of serious poisonous and corrosion gas, therefore, gas reservoir with high H₂S content s belongs to dangerous gas reservoir. Then, gas reservoir with high H₂S content s belongs to special gas reservoir, because There is some special phenomenon, the sulfur deposition, the change of gas phase composition, and damage to the reservoir due to the solid sulfur built-up in the pore, during the gas reservoir development. The sulfur deposition would decline the porosity and pemieability of reservoir, affects the productivity of gas reservoir.Based on the passed theory of gas reservoir with high H₂S content, and has introduced the gas-solid flow theory in aerodynamics field, has made the dynamics model to simulate the sulfur particle flowing and the critical gas flow velocity model to simulate the particle precipitation. In the paper, based on the dynamics model and the critical gas flow velocity model, has made the sulfur particle flowing and deposition mathematic model of gas reservoir with high H₂S content, and included the porosity decline model and the permeability decline model. Then, has made the finite difference model, and developed the computer program of the model by VB to simulate gas reservoir with high H₂S content calculation example in SPE36707 paper. Solution of the paper's model is consistent with the solution of Roberts's, but solution of the paper's model is a little higher than that of Roberts's for the model in the paper including the sulfur particle flowing. Therefore, the model in the paper is reliable.Based on the sulfur particle flowing and deposition model of gas reservoir with high H₂S content in the paper and calculation program, has calculated and studied factors of affecting sulfur particle deposition, and made some conclusions: it is important and necessary to the sulfur is resolved into gas as first and the sulfur concentration is saturated; there are three affected respects that the period of steadily production would be shorted, the period of production decline would be shorted, the decline rate in the period of production decline would decline, and the degree of reserve recovery would decline, due to the sulfur deposition. When the gas rate is constant, the porosity is higher and the sulfur particle deposition rate is slower; the permeability is higher and sulfur particle deposition rate is slower; the H₂S content...