Abstract: In a system for optimizing natural gas production in response to real-time variations in wellbore parameters, a PLC or other wellsite intelligence technology is used to monitor liquid and gas production from the wellbore under friction-loaded conditions. Using baseline production data obtained during production tests, the PLC determines and initiates the appropriate operating mode for the wellbore to optimize a selected production criterion to suit measured wellbore parameters. The operating mode either a continuous clean-out mode, in which gas is continuously injected into the wellbore to control liquid loading, or an intermittent clean-out, in which liquid loading is regulated by intermittent gas injection. In preferred embodiments, the system uses bladder-type control valves having upstream and downstream solenoids, to control production tubing flow rate within a range between upper and lower set points.

Abstract: In a system for optimizing natural gas production in response to real-time variations in wellbore parameters, a PLC or other wellsite intelligence technology is used to monitor liquid and gas production from the wellbore under friction-loaded conditions. Using baseline production data obtained during production tests, the PLC determines and initiates the appropriate operating mode for the wellbore to optimize a selected production criterion to suit measured wellbore parameters. The operating mode either a continuous clean-out mode, in which gas is continuously injected into the wellbore to control liquid loading, or an intermittent clean-out, in which liquid loading is regulated by intermittent gas injection. In preferred embodiments, the system uses bladder-type control valves having upstream and downstream solenoids, to control production tubing flow rate within a range between upper and lower set points.

Abstract: Migration of air through a flanged connection into piping containing a gas under negative pressure is prevented by disposing concentric inner and outer gaskets between the flange faces, so as to form an annular chamber into which a blanketing gas is introduced at a pressure higher than atmospheric. Air tending to migrate through the outer gasket is blocked by the higher-pressure blanketing gas in the annular chamber. The blanketing gas pressure is maintained at a level higher than atmospheric notwithstanding any fugitive emissions through the outer gasket. The annular chambers of multiple flanged connections may be interconnected to blanket multiple flanged connections using a single source of blanketing gas. The blanketing gas may be the same type as the gas under negative pressure. In sour service applications, an inert blanketing gas may be used to prevent leakage of sour gas to atmosphere through flanged connections.

Abstract: The present invention provides a method and apparatus whereby the intake pipeline running between the production chamber of a natural gas well and the suction inlet of an associated wellhead compressor is completely enclosed, in airtight fashion, within a jacket of natural gas under positive pressure (i.e., higher than atmospheric). Being enclosed inside this “positive pressure jacket”, the intake pipeline is not exposed to the atmosphere at any point. This allows gas to be drawn into the compressor through the intake pipeline under a negative pressure, without risk of air entering the intake pipeline should a leak occur in the pipeline. If such a leak occurs, there will merely be a harmless transfer of gas from the positive pressure jacket into the intake pipeline. If a leak occurs in the positive pressure jacket, gas therefrom will escape into the atmosphere, and entry of air into the positive pressure jacket will be impossible.

Abstract: A natural gas production system prevents liquid accumulation in the wellbore and minimizes friction loading in the wellbore by maintaining production gas velocity above a critical minimum velocity. A pressurized gas is injected into the well to supplement the flow of production gas such that the velocity of the total gas flow up the well exceeds the critical velocity. A choke is fitted to the gas injection line, and total gas flows are measured by a flow meter. A flow controller compares the measured total gas flow rate against the critical flow rate, and determines a minimum gas injection rate required to maintain the total gas flow rate at or above the critical flow rate. The flow controller then adjusts the choke to achieve the desired gas injection rate. The injection gas may be recirculated production gas from the well, or a gas from a separate source.

Abstract: A natural gas production system prevents liquid accumulation in the wellbore and minimizes friction loading in the wellbore by maintaining production gas velocity above a critical minimum velocity. A pressurized gas is injected into the well to supplement the flow of production gas such that the velocity of the total gas flow up the well exceeds the critical velocity. A choke is fitted to the gas injection line, and total gas flows are measured by a flow meter. A flow controller compares the measured total gas flow rate against the critical flow rate, and determines a minimum gas injection rate required to maintain the total gas flow rate at or above the critical flow rate. The flow controller then adjusts the choke to achieve the desired gas injection rate. The injection gas may be recirculated production gas from the well, or a gas from a separate source.