Pulsation Dampener for Gas Compressors Having Selectable Size Choke Openings

Abstract

A gas flow pressure pulsation dampener includes a sealed housing having an inlet port, an outlet port a center section disposed between the inlet port and the outlet port. A choke plate is rotatably disposed in the center section and has a plurality of different size openings disposed circumferentially about the plate. The plate is positioned in the center section so that the openings are placed between the inlet port and the outlet port. The size differences between the openings and the circumferential separation between adjacent openings are selected so that the plate always presents one full opening or parts of two openings between the inlet port and the outlet port. Means for rotating the choke plate are provided to select one of the choke openings to be disposed between the inlet port and the outlet port.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]Not applicable.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not applicable.BACKGROUND OF THE INVENTION[0003]1. Field of the Invention[0004]The invention relates generally to the field of measurement of flow rate of gas discharged from a compressor. More particularly, the invention relates to pulsation dampeners used to improve the accuracy of measurement of gas flow rates under variable compressor output conditions.[0005]2. Background Art[0006]Natural gas is typically transferred from producing wellbores to pipelines. The pipelines ultimately are arranged to distribute natural gas to end users. Flow measurement devices are located at places where custody of the gas changes, for example, in a producing field with gas produced from a number of wells to a gas transportation entity owned pipeline.[0007]Compressors are commonly used to raise pressure of the gas from the “upstream” side pressure at custody transfer point...

AI Technical Summary

Problems solved by technology

There is a well understood measurement problem when measuring natural gas flow rates when a compressor is used as described above.

The opening and closing of a valve used in the compressor compression causes a pulsating wave that strikes the primary measuring device and creates a false indication of increase in the flow rate.

The problem with the foregoing solution is that it is a disadvantage to the transferor (upstream custodian) of the gas.

In such case, the gas transferor's (e.g., producer's) compressor has to work much harder because it is output restricted.

In the case of compression having producing wells as the input, the wells cannot produce to capacity, making them vulnerable to “sanding” (entry of formation particles into the wellbore) and the wells would need to be reworked at considerable expense.

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