Abstract: The shale interlayers in Kela-2 gas field are penetrated or not by the fractures? The sand-shale interbedding 3D geologic model is then developed to simulate the fracture distribution through the relationship between fractural parameter and stress variation as well as extending trend of fractures in the shale. It suggests that the maximum thickness for the fractures extending in the shale is 4 meters. Hence, the faults in this field are classified into partially penetrated faults and totally penetrated faults, and the sealing effectiveness of the shale interlayers is evaluated. It is considered that the totally penetrated faults are mainly found in the southern Kela-2 gas field, particularly at the top of Baxigai formation; the partially penetrated faults mainly found in the northern, most existing in calcium shale interlayer of the Kumugeliemu group.

Key words: Kela-2 gas field, shale cracks, numerical simulation, fracture penetration, cap rock sealing