Abstract: Huan2 - 11 - 13 block of Huanxiling oilfield is a low permeability and low porosity reservoir, and the average effective thickness of oil layer is 3. 9m. By using vertical wells, lager well spacing density, lower degree of single well reserves control and higher drilling costs will be the problems. After feasibility demonstration, horizontal well technology is believed to be suitable for low permeability reservoir with thin layers, because the technology can bring its advantages into full play such as higher production and larger contact area between horizontal well and oil layers. When it is put into production, the average oil production will be 17. 9t per day, which is 9 times of that in vertical wells nearby. At the same time, the development improvement will provide good reference and useful guidance for reservoirs of the same type in the future.