Effect of Sulfur Deposition on the Horizontal Well Inflow Profile in the Heterogeneous Sulfur Gas Reservoir.

A semianalytical coupled reservoir/wellbore model based on the volumetric source for horizontal wells of sulfur gas reservoirs is presented, which considers sulfur deposition and permeability heterogeneity. Compared to the results without considering the sulfur deposition effect, the results of this paper model is better fitted to field production data and average relative errors of two simulated results are 8.37% (considering sulfur deposition) and 23.38% (not considering sulfur deposition). Based on the model, we perform sensitivity in terms of various sulfur depositions, producing pressure drop, and permeability contrast. Results show that the production decreases with increased sulfur deposition, and the flow rate along the wellbore in the horizontal well decreases because of sulfur deposition. The production without and with sulfur deposition increases with increased producing pressure drop, while the production without sulfur deposition is higher. Also, higher producing pressure drop causes a higher nonuniform inflow profile along the horizontal well. Sulfur deposition can reduce a nonuniform biased inflow profile along the horizontal well in heterogeneous sulfur gas reservoirs, but the horizontal well production is reduced. Therefore, sulfur deposition is crucial for the production prediction and inflow profile along the horizontal well in heterogeneous sulfur gas reservoirs.