Centrifugal Compression Machinery For Wet Natural Gas Applications

摘要

Preliminary performance measurements and a scheme to recover lost performance. Wet gas compression during upstream production is a major concern for the oil and gas industry, mainly because of the presence of liquid hydrocarbons, as high as 13% by mass fraction in the compressed gas, affecting the system performance. Traditionally, compressors are designed for operation with only dry gas; hence, ingesting a liquid-gas mixture causes the compressor to operate in an off-design condition. The off-design operation with wet gas leads to reduction in efficiency and requires up to two times the power as that of dry compression to maintain the flow and pressure ratio equivalent to dry gas operation [1]. To quantify the effect of wet gas on compressor performance, proper characterization of the flow through the compressor impeller is necessary. Specifically, a quantitative study of the effect of wet gas on compressor aerodynamics is needed. This paper presents an experimental study of wet gas flow around a NACA 0012 airfoil using air and water in an open-loop wind tunnel. Airfoil performance is quantified for both dry and wet conditions with lift and drag measurements taken for a range of liquid flow rate and airfoil angles of attack. The wet flow consists of a fairly homogenous mixture of air and water droplets at the blade midspan, where the pressure sensors are located. The results of this work quantify the effects of wet gas reducing the aerodynamic performance. This paper further proposes a solution to mitigate the performance degradation as a result of wet gas flow. The method involves ejecting pressurized air through holes in the airfoil surface to eliminate the liquid film buildup on the airfoil. The gas ejection design offers a possible solution to developing rugged compressors for operation in wet gas conditions. The paper will be of interest to end users and designers of compression machinery for wet gas applications.