水平井裂缝性储层阵列侧向测井正演响应影响因素

Influencing factors of array laterolog forword response for fractured reservoir based on horizontal well

裂缝性储层中裂缝的发育特征对储层产能有重要影响,侧向类测井由于其较强的电流聚焦特性,常用于裂缝性油气藏的评价工作。阵列侧向测井仪是一种新型的侧向测井仪器,具备更强的电流聚焦能力和更高的纵向分辨率。基于平板状裂缝模型,建立三维宏观各向异性球状介质模型,运用三维有限元数值算法,研究了水平井中阵列侧向测井仪在裂缝性地层中的响应特性。研究表明:仪器响应随裂缝角度的变化会出现幅度差极性变化,且临界角大小与裂缝孔隙度有关;仪器响应随裂缝孔隙流体电阻率的增大而增大,基岩电阻率与裂缝孔隙流体电阻率比值小于100后,裂缝孔隙流体电阻率变化对仪器响应影响不大;仪器响应随基岩电阻率的增大而增大。该研究为裂缝性储层的定性、定量评价提供一定参考依据。

The developmental characteristics of fractures in fractured reservoirs have an important effect on reservoir productivity. Lateral well logging is often used in the evaluation of fractured reservoirs because of its strong current focusing characteristics. The array laterolog tool is a new type of lateral logging instrument with stronger current focusing ability and higher vertical resolution. Based on flat plate fracture model, a three-dimensional macroscopic anisotropic spherical media model was established, and the three-dimensional finite element numerical algorithm was applied to study the response characteristics of array lateral logging instrument in horizontal wells in fractured formation. The research shows that the response of the instrument varies with the angle of the crack, and the magnitude of the critical angle is related to the fracture porosity; the instrument response increases with the resistivity of the fracture pore fluid, when the resistivity ratio of bedrock resistivity to fracture pore fluid resistivity is less than 100, the resistivity change of fracture pore fluid has little effect on the response of the instrument; the instrument response increases with the increase of the bedrock resistivity. This study provides a theoretical reference for qualitative and quantitative evaluation of fractured reservoirs.