海上高温高压气井关井井底恢复压力计算与应用

摘要

高温高压气井井底压力的计算必须考虑井筒内温度变化的影响,压力和温度相互耦合,必须同时求解.目前考虑井筒传热、温度和压力耦合的计算方法主要适用于稳定流,对于关井期间的瞬变流动并不适用;同时,海上高温高压气井井筒传热需考虑海水的影响,目前这方面的研究实例较少.针对以上问题,从基础方程推导,建立了考虑井筒续流、井筒与周围地层或海水间传热的温度压力耦合计算模型,并成功应用于南海西部海域M气田M1井关井井底恢复压力计算和试井分析,为海上高温高压气井井筒温度、压力计算及优化试井设计奠定了基础.%The calculation of the bottom hole pressure(BHP)in the high temperature and high pressure the gas wells with should consider the temperature changes inside the wellbore.The coupling of the pressure and temperature need to be solved simultane-ously.The current calculation methods considering the wellbore heat transfer,and the coupling of pressure and temperature mainly apply to the steady flow.However,they don't apply to the transition flow during the shut-in period.Meanwhile,the wellbore heat transmission of the offshore gas well in high temperature and high pressure should consider the effects of sea water.Nevertheless, there are fewer examples of this research.According to the problems above and based on the basic equation,we established a new calculation model,which considers wellbore storage,and the heat transfer among the wellbore,adjacent formation and sea water. This method is successfully applied to the BHP calculation and well testing analysis for the well M1 during the shut-in period in M gas field of the western South China Sea,thus providing the basis for the temperature and pressure calculation and well testing opti-mization of high temperature and high pressure offshore gas well.