Research On The Reservoir Characteristics Of The Bektas Oil Field In Kazakhstan

Bektas oil field is an important oil field in the Republic of Kazakhstan.The oil field in located in the south of the Turgay Basin,and the basin were formed in the course of five main stages of tectonic evolution: basement forming,passive margin,Mesozoic rifting,late Mesozoic subsidence and Himalayan compression.Its main strata is the Upper Paleozoic marine strata and Mesozoic and Cenozoic terrestrial strata,and most of the hydrocarbon is located in the Mesozoic strata.The source rocks are Middle-Upper Jurassic shale and mudstone.The proven productive reservoirs in the South Turgay Basin are Lower Cretaceous,Middle Jurassic and Upper Jurassic clastics.The best seals are represented by several mudstone intervals in the Middle Jurassic-Lower Cretaceous.The Bektas oil field is an anticline in the Aryskum Depression,and many normal faults exist in the oil field.The main reservoir is the M-0-2 sand body in the Lower Cretaceous Daul formation,and the sedimentary facies is composed of two stages of meandering river.The rock types of the reservoir are purple and variegated mudstone,gray and brown siltstone and fine-grained brown sandstone.The average porosity of the reservoir is 20.8%,and the average permeability is 61.08×10-3?m2.In general,the reservoir is composed of average porosity and low permeability rocks.