Mr. Howlaway eyed my equations suspiciously, “I can see that you have developed a method to predict the combination of the gas production rate and wellhead pressure necessary to keep my wells from loading -up with liquid. But suppose the production rate that the reservoir can support is too low, or the wellhead pressure is too high to achieve the minimum entrainment velocity. What should I do about that?”
Of course, there were a wide variety of answers to Mr. Howlaway’s question. Major industries have been created to assist gas producers to keep wells from loading up with liquids. Gas lift Mandrels and plunger lift systems are just two of the many gas lift downhole methods commonly employed to remove liquids from gas wells. However, as far as retrofitting low pressure wells at the surface is concerned, the simplest most cost effective means to remove accumulated liquids from a well is an “Intermitter.”
Figure 1-3 illustrates a typical Intermitter installation. A motor on-off valve located downstream of the high pressure separator alternately shuts-in and opens-up flow from the well. Wellhead pressure is allowed to build to several hundred psig above the pressure in the gas collection lateral. When the intermitter motor valve springs open, the sudden release in pressure creates a surge in gas flow through the tubing string. The accelerating gas flow reaches and surpasses the entrainment velocity, and the well is thus unloaded.