异常高压低渗凝析气藏G49X井试井解释分析

Testing Interpretation and Analysis of the G49 Deviated(X) Well in Abnormal High Pressure and Low Permeability Condensate Gas Reservoir

在凝析气田的勘探开发过程中,不稳定试井方法发挥着极其重要的作用。下第三系沙三下段是冀中坳陷廊固凹陷天然气开发的重要后备区域之一。G49X井是该区的一口预探井,清楚的了解和掌握G49X井的气藏地层信息为准确的认识该区地层提供了可靠的科学依据,对该区天然气藏的开发部署具有重要意义。通过G49X井的地层压力和气藏类型分析,该井为异常高压、中等凝析油含量且不带油环的凝析气藏。该井压力恢复双对数曲线前期表现出了早期井筒储集阶段特征,拟压力导数曲线中期出现了两段斜率为负值的直线段、半对数曲线中后期出现了两段斜率为正值的直线段,表明了该井具有凝析气藏内外两区径向复合的典型地层特征。该井的试井解释成果对该区凝析气藏的开发具有重要的指导意义。

The transient well testing method plays an extremely important role in the exploratory development of the gas condensate field. The Eogene lower Sha3 member is the key candidate reservoir of the gas development in Langgu Sag in Jizhong Depression. The G49 deviated well is an exploratory well in the zone,of which to understand and grasp the stratigraphic information clearly provides the scientific basis for knowing this area,which has an important sense for the natural gas reservoir development and deployment. By analyzing the reservoir pressure and the gas reservoir types of the G49 deviated well,it indicates that the well is the condensate gas reservoir which is non-oil ring,abnormal pressure,and containing medium condensate oil. The early stage of the build-up log-log plot has the feature of the early well-bore storage stage,and the medium content of the pseudopressure derivative curve is appear two straight line segments whose slope are different negative values,after the middle of the semi-log plot shows two line segments whose slope have different positive values,which has the characteristics of the typical inside and outside areas of the radial composite reservoir in the condensate gas reservoir. The well test analysis results have an important guiding significance to the gas condensate reservoir development.