The Control Effect of Equipment Operation on the Formation of Wellbore Hydrates Under the Production Conditions of Deepwater Gas Wells

Equipment operations during deepwater gas well production increase the risk of hydrate generation. In this paper, the density model of fluid changes caused by equipment operations during wellbore production is improved based on the temperature and pressure model of wellbore of deepwater gas wells. The risk area and rate of hydrate generation in the wellbore by equipment operation under production conditions are analysed. The roles of tool size, tool movement speed, and gas well production on the control of wellbore temperature and pressure were clarified. The results of the study found that tool size affects wellbore hydrate generation with a critical value. When the percentage of tool size is less than 50%, the larger the tool size is, the greater the extent of hydrate generation and deposition rate in the wellbore. After 50%, the larger the tool size, the smaller the hydrate generation range and deposition rate. The gas density in the wellbore does not change much under the condition of different movement speeds of tools of the same size. That is, the movement speed of the tool has almost no effect on the wellbore temperature and pressure fields and does not change the risk of hydrate generation. Production rate is another key factor in controlling hydrates. As the production rate increases, the fluid density in the wellbore gradually decreases, and the risk of hydrate generation decreases. And when the tool moves below the mudline, the wellbore temperature, pressure field, and wellbore hydrate generation rate become less affected by the tool size. The size of the tool mainly affects the hydrate generation risk in the wellbore above the mudline.