西湖凹陷储层保护施工门限探讨

西湖凹陷探井表皮系数在0～80之间，随着储层物性条件变好，表皮系数先增大后减小，表现出低孔渗污染小、中-高孔渗污染大、特高孔渗污染解除效果好的特点。污染对气井产能有一定的影响，但产能主要与储层本身物性相关。对于物性极差的储层，仅通过储层保护，产能仍无法有效释放，造成了经济损失。针对上述问题，结合试油资料，采用测试法，明确储层动用的门限值，为储层保护的实施提供理论参考。计算表明，渗透率下限为1.19×10?3 μm2，孔隙度下限为9.81%，含水饱和度上限为46.2%，验证符合率为86.36%。当储层物性在门限值范围内，表明储层在自然条件下具有产能，可进行必要的储层保护措施；当储层物性不在门限值范围内，需考虑必要的改造措施以获得产能。

Discussion on Threshold Value of Reservoir Protection in Xihu Sag

The skin factors of exploratory wells in Xihu Sag are 0～80. With the improvement of reservoir physical properties, the skin factor increases firstly and then decreases, which shows that the formation damage in low porosity and permeability oil fields is low, which in medium-high porosity and permeability oil fields is high, and recovery effect of formation damage in ultra-high porosity and permeability oil fields is good. Damage has a certain impact on gas well productivity, but the productivity is mainly related to the physical properties of the reservoir itself. For reservoirs with extremely poor physical properties, productivity can not be effectively released only through reservoir protection and it causes economic losses. In view of the above problems, combined with well testing data, the test method is used to determine the threshold value of reservoir production, which provides theoretical reference for the implementation of reservoir protection. The calculation shows that the lower limit of permeability is 1.19×10?3 μm2, the lower limit of porosity is 9.81%, the upper limit of water saturation is 46.2%, and the verification coincidence rate is 86.36%. When the physical properties of the reservoir are within the threshold value, it indicates that the reservoir has productivity under natural conditions, necessary reservoir protection measures can be taken; when the reservoir physical properties are not within the threshold value range, it is necessary to consider the reconstruction measures to obtain productivity.