The Preference Of Drainage Gas Recovery Methods And Safety Assessment Of Gas Well With Water Drainage

In the exploitation of gas fields, with the decreasing of gas deposit's pressure and natural gas's velocity, the water and condensed liquid from gas deposit can't be carried over mineshaft by natural gas, so they resort in the mineshaft and then come into being"the hydrops of gas well"; Because the hydrops of gas well affect the production of gas well badly and also lead to enterprise's economic efficiency declined. Taking drainage gas recovery measures is necessary, which can increase the production of gas fields.There are many drainage gas recovery methods, but each of them has its advantages and disadvantages. And the different process methods have been implemented in the same gas well or the same process method has implanted in different wells, the results are completely different. How to choose the best and the safest drainage gas recovery method according to the actual situation of gas well and gas field has become the principal settlement problem of gas fields with water development. The best and the safest drainage gas recovery method can increase the total benefits and also can enhance security of the gas well's development.In view of the above questions, the paper studied a lot of questions and put forward some innovative approaches. First, The critical velocity and the critical liquid carrying flow rate were calculated, and then a critical liquid carrying flow rate formula was presented, this formula considered the influence factor such as: wellhead back pressure; and the question of under what circumstances that the liquid drop can be carried out by airflow also be probed in this paper. Second, An optimal decision system of gas well's drainage gas recovery was established. This system based on the relatively mature and extensively used drainage gas recovery methods and optimal decision principle. This system could choose the best drainage gas recovery method according to the actual situation of gas well and gas field. Third, In accordance with principles of safety assessment as well as a series of safety assessment methods, the drainage gas recovery well was carried out equipment safety evaluation. Finally, the optimization and safety assessment system software of gas well's drainage gas recovery was developed with Visual C++ object-oriented language. Through this system, we can choose the best and the safest drainage gas recovery method for the specified gas well, which can also achieve the most optimal of gas well and gas field's economic benefit and security.