利用可动水饱和度预测川中地区须家河组气井产水特征

为了准确预测四川盆地川中地区上三叠统须家河组不同储层的产水特征，应用核磁共振结合离心的方法测试了大量岩样的可动水饱和度，并将测试结果引入到常规测井数据解释中，形成了可动水饱和度的常规测井解释方法。在分析储层可动水饱和度与气井产水特征之间关系的基础上，绘制出了目标区块可动水饱和度分布图。研究结果表明：广安须家河组四段和合川须二段储层比广安须六段储层可动水饱和度高；储层可动水饱和度与气井产水特征之间具有明显的正相关关系，可动水饱和度越高，储层产水越严重，应用可动水饱和度能有效预测储层产水特征；广安2井区须六段储层中南部可动水饱和度较低，为低产水风险区；广安106井区须四段中部储层可动水饱和度较低，为8%～10%，属较低产水区，西南和东南两翼可动水饱和度高，产水风险较大。该研究成果对于井位优选、降低气井产水风险具有指导作用。

Movable water saturation used for the forecast of water production features in gas wells in the Xujiahe Formation of Middle Sichuan Basin

For an accurate prediction of the water production characteristics of different reservoirs in the Xujiahe Formation of Middle Sichuan Basin, nuclear magnetic resonance is used in combination with the centrifugal method to test movable water saturation of a large number of rock samples. Furthermore, the test results are introduced into conventional logging data interpretation, the method of which is thus used for the interpretation of movable water saturation. Based on the analysis of relationship between the reservoir movable water saturation and the gas well production characteristics, a distribution map of movable water saturation in the target block is drawn. The test demonstrates the following results: (1) The reservoirs in the 4th member of the Xujiahe Formation in Guan'an and the 2nd member of the Xujiahe Formation in Hechuan are with higher movable water saturation than that in the 6th member of the Xujiahe Formation in Guang'an. (2) A significant positive correlation is shown between reservoir movable water saturation and gas well production features. In other words, the reservoirs have higher water production with the higher movable water saturation. Thus movable water saturation can be used for an effective prediction of the reservoir water production characteristics. (3) The south central part of the reservoir in the 6th member of the Xujiahe Formation in the Guang'an 2 wellblock is with low movable water saturation and at risks of low water production. The central part of the reservoir in the 4th member of the Xujiahe Formation in the Guang'an 106 wellblock is with low movable water saturation (i.e. 8% ~ 10%) and is classified as an area with relatively low water production, while southwest and southeast wing areas are with high movable water saturation, with a comparatively high risk of water production. These results play an important role in guiding the well location and reducing the risk of water production in gas wells.