ANALYSIS OF HYDRATE FORMATION PREVENTIONON PILOT TESTS ON THE EXAMPLE OF A GAS CONDENSATE FIELD IN THE REPUBLIC OF KAZAKHSTAN

Abstract

One of the most important problems in the operation of gas condensate fields is the formation of gas hydrates. Depositing on internal walls of pipes, hydrates sharply reduce a channel capacity of pipes that can lead further to an emergency shut-down. Costs of the oil and gas companies for control and prevention of gas hydrate plugs are a significant part of the cost of operating fields and transporting gas. Therefore, reducing the cost of control and prevention of hydrate formation in gas production system and for its further gas transportation is of interest to many operating companies in the oil and gas industry. Hydrate formation is a process that occurs when temperature and pressure drops, which lead to a decrease in the elasticity of water vapor and the capacity of the gas, and, consequently, the formation of unstable hydrocarbon compounds with water, i.e. hydrates. Hydrates are white crystals that look like snow or ice. Crystal hydrates consist of one or more gas molecules (methane, propane, carbon dioxide) and water. The main factors determining the conditions for the formation of hydrates are the composition of the gas, its pressure, temperature, full saturation of the gas with water vapor. In this paper, the gas condensate field of the Republic of Kazakhstan is considered. A brief geological characteristic of the reservoir, the component composition of the gas-condensate mixture and a review of methods to control gas hydrates deposits are given. As the main method, the use of the multi-segment valve of the Severn Glocon company was adopted. An assessment of the advantages and disadvantages of the valve design was made, on the basis of which conclusions about the advisability of further valve use were made.