2. The principle of small tubing drainage gas production method is that the smaller the tubing diameter, the greater the gas velocity and the stronger the liquid carrying capacity. If the tubing diameter is selected reasonably, there will be no water at the bottom of the well. This method is suitable for gas wells with high formation pressure and low water production in the initial stage of water production.
3. Foam drainage gas recovery method is to add foaming agent into the well through tubing or casing. The foaming agent will dissolve in the accumulated water at the bottom of the well and react with water to form bubbles, which can not only reduce the relative density of accumulated water, but also take the water generated in the formation out of the ground with the air flow. This method is suitable for gas wells with high formation pressure and relatively low water production.
4. The plunger gas lift drainage gas recovery method is to run the plunger in the tubing. When tripping in, the flow channel in the plunger is in an open state, and the plunger moves downward under the action of its own weight. When it reaches the bottom of the tubing, the flow channel in the plunger automatically closes. Because the pressure acting on the bottom of the plunger is greater than the pressure acting on the top, the plunger begins to move upward and drain the accumulated water above the plunger to the ground.
When it reaches the top of the tube, the flow channel in the plunger automatically opens again and moves down again. Through the reciprocating motion of the plunger, the accumulated liquid can be continuously discharged. This method is suitable for gas wells with sufficient formation pressure and large water production.
5. Deep well pump drainage gas production method is to control the bottom hole pressure by using the deep well pump, sucker rod and surface pumping unit that are lowered into the well, pump water through tubing and produce gas through casing. This method is suitable for gas wells with low formation pressure, especially for water production wells in the middle and late stage, but the operation cost is relatively high.
Extended data:
As of 20 17, the proven geological reserves of natural gas in China are only 14.4 trillion cubic meters, accounting for 17% of the technically recoverable reserves.
Except for a large number of unproven natural gas reserves, the data in China Natural Gas Development Report (20 18) shows that in 20 18, the proportion of proven natural gas reserves in China was over 44%. Even at the current technical level, the remaining economically recoverable reserves are still 3.9 trillion cubic meters, and the development cost of most resources still has obvious price advantages compared with the natural gas imported from China-Myanmar pipeline.
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