Patent ID: 6991034

Claim:
A method of producing natural gas from a well extending from ground surface into a subsurface production zone within a production formation, wherein: (a) the wellbore is lined with a casing, said casing having perforations in the production zone; (b) a tubing string extends through the casing and terminates adjacent to the production zone above the bottom of the wellbore; and (c) said casing defines an annulus between the tubing and the casing, the bottoms of said annulus and casing being in fluid communication with the well bore; said method comprising the steps of: (d) determining a minimum total gas flow rate for the well; (e) injecting a pressurized injection gas into an injection chamber selected from the annulus and tubing, so as to induce flow of a gas stream up a production chamber selected from the annulus and the tubing, said production chamber not being the injection chamber, said gas stream comprising a mixture of the injection gas and production gas entering the wellbore from the formation through the casing perforations; (f) measuring the actual total gas flow rate in the production chamber; (g) comparing the measured total gas flow rate to the minimum total flow rate; (h) determining the minimum gas injection rate required to maintain the total flow rate at or above the minimum total flow rate, according to whether and by how much the measured total flow rate exceeds the minimum total flow rate; and (i) adjusting the gas injection rate to a rate not less than the minimum gas injection rate.