海上油气井试井解释潮汐效应消除方法

摘要

潮汐效应会造成压力恢复测试过程中压力曲线波动,导致试井解释结果不能真实反映储层特征.在无实测海底潮汐数据的情况下,建立了一种潮汐效应快速消除方法,首先确定考虑潮汐影响的关井恢复压力函数,然后利用该函数运用非线性最小二乘法对实际关井压力恢复曲线进行拟合,得到潮汐压力函数的系数,从而将潮汐效应从压力恢复曲线中剥离.实例应用表明,本文方法可以快速、有效地消除潮汐效应的影响,保留真实的储层压力和边界特征,对提高海上试井解释精度有重要意义.%Tidal effect can lead to fluctuation of pressure curve in pressure buildup test,which causes that the interpretation results of well test cannot reflect real reservoir characteristics.A fast removal method of tidal effect of offshore well test analysis is established in the absence of measured ocean tidal data.First,the buildup pressure function is determined by considering tidal effect.Then,the coefficients of tidal pressure function are optimized by fitting the measured buildup pressure data through the nonlinear least square method,which is used to separate tidal signal from measured buildup pressure data.Application shows that the method can quickly and effectively eliminate the influence of tidal effect and retain the true characteristics of pressure and boundary,which has significance to improve the offshore well test interpretation accuracy.