Fractal Model for Predicting Elemental Sulfur Saturation in the Presence of Natural Fracture

Abstract

Sour gas reservoirs are an important part of unconventional gas reservoirs, which are widely distributed in the world. However, elemental sulfur deposition, channel plugging, and productivity reduction consequentially occur in the development of high sour gas fields as pressure drops. The accurate prediction of sulfur deposition is a very important work for sour gas reservoirs. In this paper, a fractal model is presented for predicting elemental sulfur saturation in the presence of natural fracture. The model takes into consideration the effects of non-Darcy flow. In addition, the influence parameters such as fractal dimension, fractal index, and non-Darcy flow are studied. The results showed the following: (1) sulfur deposition was overestimated by Hu’s model, and this paper model is more accurate for prediction of sulfur deposition; (2) elemental sulfur deposition decreases with the increase of the fractal dimension, while elemental sulfur deposition increases with the decrease of the fractal index; and (3) non-Darcy flow should be considered because it causes a faster rate of sulfur deposition. This research will provide a basis and reference for predicting elemental sulfur saturation in the presence of natural fracture for sour gas reservoirs.

Sensitivity Evaluation and Stimulation Optimization of Ultralow Permeability Sandstone Reservoir

“…The performance of the acid solution directly determines the success or failure of the whole acidification operation . At present, the research of acid systems mainly focuses on delaying the reaction rate of acid rock, and great achievements have been made. − However, the dissolution rate of the rock mineral composition is also an important factor affecting the effect of acid pressing. The conductivity of acid erosion fractures is better when the easily dissolved substances account for 30–40% of rock mineral composition .…”

Microscopic Mechanism and Percolation Model of Dynamic Deposition of Elemental Sulfur Particles in Acidic Gas Reservoirs

“…7 Their model considered sulfur deposition and permeability heterogeneity, employing a volumetric source approach. Li et al (2021) introduced a fractal model for predicting elemental sulfur saturation in the presence of natural fractures. 8 In recent research, Lu et al (2024) 9 used reynolds stress model and discrete particle model to simulate particle deposition in three-dimensional corrugated rough wall channels.…”

“…Li et al (2021) introduced a fractal model for predicting elemental sulfur saturation in the presence of natural fractures. 8 In recent research, Lu et al (2024) 9 used reynolds stress model and discrete particle model to simulate particle deposition in three-dimensional corrugated rough wall channels. The discrete random walk model was used to simulate the turbulent diffusion of particles.…”