THE EVALUATION AND PREDICTION OF CARBONATE RESERVOIRS OF ORDOVICIAN IN EASTERN LUNGU REGION,TARIM BASIN

Under mutual-controlling of tectonic disruption action and diagenesis,the main type of Ordovician carbonate reservoir is cave-fissure system in eastern Lungu region.The main type of reservoir is fissure,and fracture-vug takes second place.Different Ordovician formations have different characteristics of developed reservoirs,and the range of effective thickness of reservoir of upper formation of Yingshan-Yijianfang-lower part of Tumuxiuke is 260-300m.The main effective reservoirs mainly develop in grain limestone of bank-facies,and appears in bedded.The main effective reservoir of formation of Lianglitage distributes in belt of reef flat limestone,and appears as lenticular.The graph of distribution reservoir indicates that karstification in the study area expresses that well-developed cave of certain layers are caused by bedding karstification,while structure fault acts in the Ordovician reservoir expresses that well-developed fractures distribute along the huge fault and near the belt of flaw fault.