LWD drilling practice and understanding in low-permeability thin reservoir horizontal wells of Zhanarol Oilfield

In Zhanarol Oilfield in Kazakhstan, the reservoirs in Дю Block are in low-permeability, only 10 md, belonging to extra-low permeability reservoirs; meanwhile, the oil reservoirs in this Block are thin, only 2-3 m; the drilled vertical wells have low capacity, so the oilfield has not be effectively developed for many years. In order to tap the remaining oil potential, develop the low-permeability hard-to-produce reserves and also improve the development efficiency of low-permeability reservoirs, the horizontal well drilling technology was tried, and two horizontal wells-H5147 and H4061 were successfully drilled together with critical techniques like pilot hole drilling, LWD geo-steering and geological logging, etc. which effectively ensured the target hit rate of the horizontal section and encountering rate of oil reservoir and finally obtained high single well productivity. The initial daily productions of single wells were 89 t and 91 t respectively, about three times of initial production of vertical well. Among the techniques, the pilot hole drilling effectively determined the depth and thickness of oil reservoir; LWD geo-steering and geological logging ensured that the wellbore trajectory was within the oil reservoir. The productivity of the two wells shows the applicability and necessity of horizontal wells and drilling technology in Дю Block.