高含硫天然气中元素硫含量测定的影响因素分析

准确测定高含硫天然气中元素硫含量对建立气藏硫溶解度模型，预测和处理硫沉积至关重要。为此，通过井口高含硫天然气中元素硫测定技术分析，并根据试验分析结果，揭示了影响元素硫准确测定的各种因素。结果表明：①不同取样位置得到的元素硫测定结果不同，需根据预测目的选择取样位置；②取样容器的结构和容积会影响到元素硫测定结果，使用前应对取样容器的容积进行准确校正；③宜采用抽空容器法和不通过取样分离器的方式来对元素硫进行取样；④样品体积不应采用流量计直接计量，而应采用计算法。结论认为，影响高含硫天然气中元素硫含量准确测定的主要因素是：取样位置、取样容器、取样管线、取样方法、压缩因子计算方法和样品体积计量方式。

Influencing factors of the sulfur content measurement in high-sulfur natural gas

To measure the elemental sulfur content in high H2S natural gas is essential to build a model for sulfur solubility of gas reservoirs and to forecast and deal with the sulfur sediments. In view of this, case studies were carried out at the wellhead. Through the experimental analysis of each step in the sulfur measurement, we confirmed that the key influencing factors and main sources of uncertainty, i.e., sampling locations, sampling containers, sampling lines, compressibility factor calculation method and sample volume metering method. Accordingly, we presented solutions as follows: (1) A proper sampling location should be selected for different predicting purposes. (2) The volume of a sampling container should be accurately corrected before use. (3) The evacuated container should be used instead of the sampling separator for sampling. (4) The sample volume should be calculated instead of being metered directly by the flowmeter.