Study On The Ordovician Sedimentary Facies Belt And Reservoir Distribution Characteristics Of The Hudson Block In The Northern Tarim Basin

This paper is based on mineralogy,sedimentary petrology and reservoir geology theory to divide and correlate the Ordovician strata of Hadson block in the northern region of tarim basin,to study the petrological characteristics,sedimentary facies,reservoir development and distribution,then to make a comprehensive understanding of this study area's sedimentary facies characteristics and plane distribution,reservoir formation and development mechanism,analyse the reservoir's distribution regulation,finally to predict the favorable zones of reservoir development.There are five kinds of Ordovician strata discovered in Hadson blocks,including Sangtamu Formation,Lianglitage Formation,Tumuxiuke Formation,Yijianfang Formation and the first member of Ymgshan Formation.Among These strata,the Tumuxiuke Formation,which is an important comparison marker bed,is characterized by obvious electrical characteristics,infundibular natural gamma and resistivity curve.The bottom of Tumuxiuke Formation is flattened to make stratigraphic correlation,while the other formation's thickness are stable with good comparison.The discovered Ordovician strata in Hadson blocks have two main rock types,which are limestone and clastic rocks.sparry grain limestone,micritic limestone particles,particles micritic limestone,micritic limestone,biological limestone are mainly distributed in Yingshan Formation and Yijianfang Formation,Yijianfang and Yingshan Formation were developed with Open platform facies with internal platform shallow water,patch reef and interbank sea subfacies.reservoir development in Yijianfang group is good.The main reservoir type in Ordovician Hudson are caves,holes,holes-cracks and fractures.Holes-cracks is the most common.The main factors which controlling development of reservoir are Lithofacies,Tectonic function and karst process.Because the measured matrix porosity reservoir is very low,it can not represent the true reservoir,the main method to predict the devolopment of reservoir is D seismic rms amplitude attribute analysis.The study found fractured reservoir mainly along the north-south fracture zone showing the distribution of the strip,for this feature to deploy wells to obtain oil and gas..