Effective Amount of Gas Released from Water and Its Significance

Key words: 
• the amount of gas released from water /
• effective amount of gas released from water /
• change of pressure /
• and temperature

Abstract: Based on the study of factors influencing the dissolution ability of gas in formation water, this paper analyses the geological conditions for gas to release from water,and points out that the decrease of temperature and pressure, increase of mineralization degree are the main causes to bring out the release of gas from water. Based on this cognition and using the relation among the amount of gas dissolved in water,and temperature and pressure conditions,the paper establishes a calculation method to study the amount of gas released from water.By analysing the losing of gas released from water on the way of migration due to diffusion and adsorption,the paper has put forward the concept of effective amount of gas released from water ,and established a research method , finally applied it in Alaxin and Erzhan gas fields in the north part of Songliao Basin.Through study on the effective amount of gas released from water of the first member of Nenjiang Formation in Qijia-Gulong Sag, it can be seen that the amount is about 8.60×10⁸m³, which is about 18.64% of geological reserves in two gas fields ,indicating that the gas released from water is the important part for gas to accumulate and form gas pool.