有关多层合采和斜井的试井解释

Well Test Interpretation about Multilayer Commingled and Inclined Well

斜井X井位于发育了一系列岩性圈闭的川西盆地斜坡带。通过剖析X井所在区块地质结构和储集层物性特征表明,构造主体部位轴线近南北向,井点附近主要有三条断层,X井自上而下钻穿茅口组和栖霞组两大储集层,其中茅口组纵向上存在多套产层。在掌握该井试井资料的基础上,将多套产层组合在一起进行试井分析,针对斜井井深结构,取斜厚值作为试井模型的有效厚度,选择直井模型代替水平井模型进行模拟运算和图版拟合,得到渗透率、储容比等储集层物性参数及断层距离等边界情况。结论认为,在不同储集层物性特征相似、共有一套压力温度系统、深度相差很小的前提下,将多套产层组合在一起进行试井分析的做法是可行的,解释结果可靠;针对斜井的试井解释,可用直井模型代替水平井模型,用斜厚值作为模型的有效厚度。直井模型所需设定的参数较少,运算的稳定性和可靠性更好。

X well is an inclined well,locating in Western Sichuan basin slope developed a series of lithological traps. Through analysis of geological structure and physical properties of reservoir around X well,it indicates that structural main parts nearly North-South axis,has three main fault near the well,X well is drilled from top to bottom of Maokou and Qixia two large formation,and among them of the Maokou has multiple reservoirs in vertical direction. Based on well test data,well test analysis is done combined with multiple sets of reservoirs,and according to inclined well structure,an oblique thickness value is taken as effective thickness,and the vertical well test model is selected instead of the horizontal one to conduct simulation and picture fitting,resulting in permeability,storativity ratio ω,other reservoir physical parameters and fault distance boundary condition. The conclusion is that,in condition of similar physical properties around different reservoirs,only one pressure and temperature system and depth difference is very small,it is feasible to put multiple layers together for well testing analysis and results are reliable. For test interpretation of slant well,vertical well model and oblique thickness value can be used instead of horizontal well model and vertical thickness value of gas well. Vertical well model needs fewer parameters and has better stability and reliability of operation.