Abstract: During drilling horizontal well, usually adopt geometry steerable drilling technology to increase the penetration rate of borehole track in oil reservoir. Geosteering technology is system engineering, and may be resolved by personnel of drilling, and geology, and well logging, and oil reservoir and logging participate in and combine with together. Combination the geosteering drilling technology characteristics with reality conditions of geology feature of drilled oil layer, drilling tool construction, well path control and field application of real-time geology curve etc., we introduce the application condition about geosteering technology in horizontal well drilling, and discuss important function of the geometry steerable drilling technology in oil layer identification, and put forward several viewpoint and suggestion that guides the geometry steerable drilling technology. Practice indicates that geometry steerable drilling technology has important function on distinguishing hydrocarbon reservoirs. It has got good application result in Cheng71-Ping4, horizontal-well geosteering parameter-measuring interpretation while drilling system presents the dependable means that can explain the real-time curve of LWD, and the results is basically in accordance with the explain results of wireline cable logging, and it has great value of employment.