南海西部异常高温高压气藏区域产能预测技术

南海西部存在大量高温高压高二氧化碳气藏，“三高”气藏气井测试费用高、产能预测难度大，设计变内压建束缚水应力敏感实验、含CO₂天然气PVT实验研究应力敏感、CO₂含量、表皮系数对高温高压气井产能的影响.通过大量实验，明确了高压气藏“两段式”应力敏感变化规律，得到了靶区应力敏感综合评价系数；分析不同压力下CO₂含量对天然气偏差系数、黏度等参数的影响，高压下影响较低压下大，基于实验数据推导建立一种适用于高中低二氧化碳含量的全范围偏差系数校正模型.最终建立同时考虑应力敏感、二氧化碳、表皮系数影响的区域产能预测图版，提高产能预测精度，降低测试费用，在南海西部高温高压气井应用效果较好. 

Regional Productivity Prediction Technology for Abnormal High Temperature and High Pressure Gas Reservoirs in Western South China Sea

A large number of high temperature,high pressure and high carbon dioxide gas reservoirs exist in the western South China Sea. Gas well test cost is high and productivity prediction is difficult in "three high" gas reservoir. Design Variable internal pressure,establishment of irreducible water stress sensitivity test and PVT test of natural gas Containing CO₂ to study the effect of stress sensitivity,CO₂ content and skin factor on productivity of high temperature and high pressure gas wells. Through a large number of experiments,the "two-stage" stress sensitivity variation law of high pressure gas reservoir is clarified,and the comprehensive evaluation coefficient of stress sensitivity in target area is obtained. The influence of CO₂ content on PVT parameters such as Z-factor and viscosity of natural gas is analyzed,the influence of high pressure is greater than that of low pressure. Based on experimental data,a correction model of full range deviation coefficient suitable for high,middle and low carbon dioxide content is established. Finally,a regional productivity prediction chart considering the influence of reservoir stress-sensitivity,carbon dioxide and skin factor is established,improves the accuracy of productivity prediction and reduces the cost of testing,which has a good application effect in high temperature and high pressure gas wells in the western South China Sea.