基于地层水蒸发的气井井筒结盐理论模型及实践--以文23储气库为例

地下储气库是保障季节调峰和平稳供气最经济、最有效的手段。为了解决高矿化度地层水气藏型储气库结盐问题,尤其是井筒结盐预测问题,保障文23储气库的安全和正常运行,通过室内实验测试了不同压力和温度条件下地层水蒸发规律,确定了地层水结盐条件;并结合地层水盐析临界条件,首次建立了将气水相态与井筒流体质量守恒、能量守恒、动量守恒、井筒流体传热进行耦合的井筒结盐理论预测模型;应用模型分析了井筒结盐机理,计算了地层水矿化度和水气比对气井结盐的影响规律。研究结果表明:①随着温度增加和压力降低,地层水蒸发速度呈指数增加,地层水结盐的临界矿化度为350 g/L;②气井结盐主要机理是从井底到井口,在井筒温度和压力变化影响下烃水平衡使得地层水蒸发加剧,地层水矿化度达到结盐临界矿化度;③气井中水气比越小(低于0.15 m^(3)·10^(-4) m^(-3)),矿化度越大(高于260 g/L),井筒结盐风险越高,结盐位置在离井口1500 m左右。结论认为,建立的储气库井筒结盐理论预测模型与矿场监测到的气井结盐规律基本吻合,有助于高矿化度地层水气藏型储气库结盐防控,对保障储气库安全高效运行具有重要意义,同时该模型可为其他储气库气井井筒结盐预测、预防提供参考。

Optical Resolution of DL-Tartaric Acid Mediated by Diastereomeric Salts Crystallization: A Useful Method for Exploring and Optimizing Experimental Conditions

A response surface modeling approach for simultaneous optimization of optical purity and yield was applied to the resolution of tartaric acid to study the effects of both the amount of the solvent and the amount of the resolving agent a-methylbenzyl amine on the resolution results. The direction of changing the experimental conditions was determined from the initial response study, and expected high yield of the pure L(+)-tartaric acid-L(-)-a-methylbenzyl amine salt was obtained.