Abstract: The igneous reservoir of Wellblock Ke?81 in Karamay oilfield is characterized by deep burial, no natural productivity in oil wells, so there is generally no effect to increase oil production without fracturing and/or acidizing. On the basis of analyses of the rock mechanics, fracture characteristics and the impact of fracturing fluid systems on fractures, the fracturing scheme is optimized, and coiled tubing bottom sealing annulus fracturing process is used to perform fracture network fracturing. Such a large displacement and high pump pressure fracturing can form fracture networks connecting natural fracures and improve flow conductivity in the reservoir for obtaining high oil production. The successful application of this technology in Well Mahu?5 will provide practical guidance for future development of Wellblock Ke?81 and similar wells