Study On The Ordovician Sedimentary And Reservoir Characteristics Of The Hotwapu Block In The Tabei Uplift

Rewapu Area is located in The North Tarim,which is an important area affecting the oil production and storability promotion of Tarim Oilfield Company.It has huge exploration and development potential.After a breakthrough in 2011,the region has entered into the stage of development and evaluation.From view of geology,this paper combines with the research methods of the theory of multi-disciplinary and huge amounts of data such as the core observation and description,drilling,well logging and seismic data in Rewapu Area and adjacent region,studying the characteristics of reservoir.Firstly,based on the characteristics of sedimentary facies of each well and depositional environment of adjacent region,it has been indicated that ordovician carbonate reservoirs of Rewapu area has five sedimentary facies,such as open platform facies,platform edge facies,drowned platform facies,clinothem facies,and diamictic continental shelf facies.The thickness of strata and sedimentary facies distribution of lateral stability The Middle Ordovician Yijianfang Formation is the depositional environment of open platform facies.The upper Ordovician tumuxiuke formation is the depositional environment of drowned platform facies and clinothem facies.The upper Ordovician Lianglitage Formation in this study,the thickness and sedimentary facies developed in the northern part of the larger changes,platform margin reef facies,sedimentary thickness is more than 100m,to the south of platform margin slope facies change,deposition thickness is obviously reduced to below 30m.The Zone area north of platform margin of the Lianglitage formation is the depositional environment of platform edge facies.With the north area of Lianglitage Formation in platform margin zone area of three obvious characteristics in platform margin,and two to the margin of platform margin depression or interbank sea mainly with platform margin beach,and a benign and three sedimentary environment evolution of platform margin reef environment,development period the main reservoir.Secondly,according to the results of seismic,logging,drilling,logging interpretation and identification of core observation and thin section,it has been indicated that the reservoir space of the study area can be divided into three types such as cave,fracture pore,fracture(known as the cave and fracture pore type,the types of reservoir space is mainly the cave,three holes,cracks;plunger core petrophysical analysis can not reflect the actual development of the main reservoir of Ordovician carbonate reservoir of block type);the formation and development of the reservoir,controlled by many factors,the main factor is the karstification and tectonic faulting.According to the single well reservoir evaluation and reservoir horizontal comparative analysis,and seismic information recognition technology and the results of seismic attribute analysis,geostatistical inversion techniques and results,logging reservoir evaluation results,it shows that the Gevap study in Ordovician Yijianfang Formation and the upper part of Eagle mountain group is the main reservoir,the main development of dot cave type and fractured vuggy reservoir,reservoir plane distribution is concentrated along the fault zone,the first and third section in Ordovician Lianglitage Formation also has the fracture vug type and hole type reservoir.