Well testing interpretation model of vertical channeling between wellbore and karst cave in fault-karst reservoir
The types of fault-karst reservoir are various and the heterogeneity is very strong,so the conventional multiple pore medium models and simple karst cave equipotential models are difficult to be widely applied.In view of the complex geological characteristics of fault-karst reservoirs,and considering the vertical channeling of large karst cave to the wellbore and the radial supply of small-scale fracture cave reservoirs to the wellbore and large karst cave respectively,a well testing interpretation model of vertical channeling between wellbore and karst cave in double-layer and double-porosity medium is established.The bottom hole pressure solution is obtained by Laplace transform method,a typical bottom hole pressure curve is drawn and the flow section is divided.The sensitivity analysis of parameters such as channeling conductivity,large karst cave radius and fracture conductivity coefficient ratio were analyzed.The results show that the conductivity of the channeling mainly affects the early channeling"concave"characteristics,and too large or too small value will cause the"concave"characteristics of the early channeling to weaken or even disappear.The radius and storage ratio of large karst caves mainly affect the"concave"characteristics of early channeling,and the larger the value,the more obvious the"concave"characteristics.The conductivity coefficient ratio of fracture system and the fracture storage ratio mainly affect the"concave"characteristics of channeling in the middle and late stages.The research results have important practical significance to the evaluation of reservoir parameters in complex fault-karst reservoir.
NETL
NSTL
万方数据
