Evaluating the Relationship Between Natural Gas Hydrocarbon Heavy-Ends Condensation and Its Hydrocarbon Dew Point HDP

Abstract

Abstract Natural gas comprises of non-hydrocarbons, light and heavy-end hydrocarbons. Although heavy-end hydrocarbons, may be present in negligible concentration in dry or lean gas, its reasonable occurrence in wet or rich gas is of great concern to all stakeholders because of their ability to retrograde and coalesce into liquid or solids. Hydrocarbon Dew Point is basically controlled by the availability and quantityof condensable heavy-end hydrocarbons in a natural gas sample. In this work, fifteen natural gas samples, collected from different flow stations and gas processing plants in the Niger Delta Region were used. In this exercise, efforts were made to establish the relationship between the liquid content of the gas or condensable hydrocarbon and the resultant measurable hydrocarbon dew point of the same natural gas sample. The natural gas samples were analyzed by Gas Chromatographic technique in reference to ASTM D1945 (2013). The results generated were reported in gallons per thousand cubic feet (GPM) of various alkane plus fractions. HDP was measured with manual dew-scope, using ASTM D1142 as standard method. NIST 1297 and Statistical tools were used to quality-check generated analytical results. The results of this work confirmed that there is a relationship between condensable hydrocarbons and practical hydrocarbon dew point. It also highlighted the need to employ gas chromatographic method as a tool to give a vivid picture of the condensable heavies that resulted in the measured HDP.