Abstract: Reservoir SH_B of O oilfield in Syria is atypical porous carbonate heavy oil reservoir with low-permeability.It strikingly features in low permeability and high viscosity.Under the present well patterns and development models,the development effect here is poor and it is manifested by three-low parameters:low ratio of produced reserves to proved reserves,low single well production and low recovery.No cost-effective and enforceable development plan has been proposed.Presently,there is no successful case on low-permeability heavy oil reservoir development and no mature technology and experience for reference.The development of this kind of reservoir is still a world-class challenge.In order to improve development benefits and realize effective development,reservoir engineering theories and methodologies,numerical simulation and economic evaluation techniques are used to study and optimize systematically the development models,well types,well patterns,well spacing,lateral length,and thermal recovery parameters of horizontal well.Research me-thods for developing carbonate heavy oil reservoir are suggested,and development strategy specifically for reservoir SH_B is proposed.The optimized development technical policy lays a foundation for development planning and provides a refe-rence for domestic and foreign analogous reservoirs.

Key words: low permeability, pore type, heavy oil, carbonate reservoir, Syria