Proposals for calculation of wells’ blowdown processin the liquid loading wells

The prospects of the Russian gas industry is closely related to further rational development of natural gas fields of the north of West Siberian, where more than 80% of Russian gas is currently produced. Accumulation of condensation water takes place in wells with low gas flow rates due to low flow velocity in boreholes. Hydrostatic pressure increases with accumulation of the liquid at the well bottomhole and prevents gas flow. Finally it leads to the stalling of the well.
Materials and methods
Using the author’s calculation model for gas critical velocity the actual gas flow velocity is compared with the critical gas velocity. The volume of the condensate fluid is determined by the delta between moisture content at the bottomhole and at the fluid lifting point. With the above mentioned values one can determine time the condensate fluid makes a column preventing well operation.
Results
In the paper the authors analyzed fluid accumulation processes in the wellbore of a liquid-loading well and calculated stalling time. The interval between the operations on well blowdown is received based on the obtained value.
Сonclusions
The proposed method helps more accurateplanning of well blowdown schedule for liquid-loading wells, reducing time and costs for well candidate selection and further period for determining liquid-loading cycle.It is important to note that only wells subjected to liquid-loading with condensate water are suitable for the method. It is difficult to predict liquid-loading cycles with other fluid types in wells. For more accurate calculation results it is also important to determine the position of gas-liquid contacts by water-cut log and pressure measurements while logging - control.