Abstract:

Fracture geometry and reservoir property are important indices to the evaluation of fracturing efficiency and the prediction of single-well productivity and recovery. In order to obtain key parameters such as fracture half-length, conductivity and formation permeability, three post-treatment evaluation methods, i.e.micro seismic imaging, net pressure matching and transient production analysis, were investigated with a field case of a multi-stage fractured horizontal well in Sulige field. The field case study verified the validity and limitation of the three methods. It proved that the three methods have their own limitations, and the post-treatment measurements obtained with microseismic monitoring, execution data and daily production need to be integrated effectively that could avoid ambiguity. The fracture half-length achieved from micro seismic often deviates from the actual value and is too large; The net pressure matching result gives a greater fracture half-length than the actual value without considering fracture closure and effectiveness effects; The result of the production data analysis gives a minimum value of fracture half-length, which is the most accurate.

Key words: multi-stage hydraulically fractured horizontal well, post-treatment evaluation, micro-sesmic surveillance, net-pressure match, production performance analysis