Optimization Of Operating Parameters Of Gas Storage In Sulfur-bearing Gas Reservoirs

There is some H2S in sour gas storage. During gas storage operation, some H2S will be produced with work gas, and it will corrode pipeline and equipment. Considering H2S influence, parameters optimization and H2S prediction duriong gas storage operation is difficult. This thesis has done some researches to study this question.Study on H2S dynamic liberation during gas storage operation. The H2S in formation water will release when formation pressure and H2S partial pressure change. But for now, it is difficult to calculate how much H2S will release. Based on Carroll formula, according to H2S content in different pressure, a new H2S dissolution model was established. This model can calculate H2S content without the volume of formation water and original H2S dissolution. According to pressure analyzing, during gas storage operation, most H2S dynamic liberation will occur in the first period, and it will reach the maximum at the last day of the first period. So in the first production section, it is better to increase some H2S purification ability on the surface.Study on H2S dynamic production and distribution. H2S production content varies periodically, and it will affect production process design. Base on X sour gas field, a mechanism model has been established to study H2S dynamic production and its main factors. It implys that during gas production, H2S flows to the bottom hole due to pressure drop, and H2S content on the surface increases quickly till the end of production. With the increasing of operation time, H2S produced in each period decrease exponentially. So at the end of the first period, H2S content is the highest, which impacts H2S purification equipments on the surface. Among those gas storage parameters, original H2S concentration, the initial gas recovery factor when gas storage is built, and work gas ratio significantly influence H2S content, on the other hand, the maximum reservoir pressure, gas injection speed, and well spacing have minor impacts. This reseach has confirmed the factors of H2S content, and provides the basis for H2S prediction.Research on H2S prediction. Considering the 3 main factors of H2S content, based on response surface design analysis, a regression model of H2S content and factors has established. It indicates that H2S content will increase with original H2S concentration, and decrease while initial gas recovery factor and work gas ratio go up. So, in order to reduce H2S content on the surface, it's better to build gas storage in low H2S area and increase initial gas recovery and work gas ratio.A software for sour gas storage parameters optimization. Some gas storage parameters belong to grey category, so grey comprehensive evaluation method is used to optimize parameters. The satisfaction function and grey matter elements matrix satisfied with sour gas storage are established, and a small parameter optimization software is programmed with VBA. With this software, parameters optimization becomes much easier than before, and based on H2S dissolution and prediction model, it can also accurately predict H2S content in each period and gas storage safety time. The parameters optimization of gas storage A has been studied as an example, and the prediction of H2S content in each production period is identical with the real. Which indicates the practicability of sour gas storage parameters optimization software.This study provides a convenient way for gas storage parameters optimization and H2S prediction, which makes it more efficient than tradition way. It provides firm support for sour gas storage construction, and significative reference for other sour gas storage design in X sour gas field.