| 摘要 |
To reactivate the abandoned watered-out gas wells by conventional method, th e water inside the well-casing is removed by means of a water pump to reduce the water hydrostatic pressure, allowing the gases coming from a reservoir entering the well-casing and flowing to the surface of the well to be recovered. The pump must run continuously and have the capaci ty to pump the existing water in the well and also the water coming from the reservoir. Thi s method is slow, costly and, at low gas prices, may not be feasible. The new invention is based on reduction of the water level in the well-casin g to a possible minimum and maintaining this level continuously by using inflatable packers and a pump. The bottom part of the well-casing is divided into three sections using these packers. A long tube (tubing), with a submersible water-pump at its end, is placed in the well- casing. This tubing protrudes trough the packers and is used for pumping the water out of the casing. A short water- pipe also protrudes through these packers and is used in connecting the uppe r part of the casing with the lower section. A one-way valve mounted on the water-pipe prevents t he reverse flow of water and gas into the upper part of the casing. A modulating-valve mount ed on the upper packer controls the water-level and passes the gas from the upper section, under the upper packer, to the upper part of the casing. By starting the water-pump, the wat er inside the upper part of the casing is removed through the water-pipe and from the lower section. After removal of the water from the upper part of the casing, the two lower packers will b e deflated thereby the gas and water from the reservoir fill the entire three sections below the upper packer. When the gas is collected on top of the water under the upper packer and the pressure increases, then the water is pushed downward to a certain level. This level will be changed by pressure fluctuation and is controlled and maintained by using available devices for water-level control. By a certain adjusted pressure for controlling the water-level, the modulating-valve open s and allows the gas collected below the upper packer, on top of the water, to be passed into the upper part of the casing and collected there. The recovered gas will then be passed through a well-head valve into a compression facility and/or into a pipeline.
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