塔里木盆地西南坳陷昆仑山前古近系卡拉塔尔组储层沉积特征及其预测评价

塔里木盆地西南缘沿西昆仑山前古近系卡拉塔尔组沉积巨厚的碳酸盐岩与碎屑岩混层,分布范围西至喀什、东至叶城县克里阳地区,有3次大规模的海侵海退,即3个沉积微旋回;沉积储层展布的划分以同由路克、和什拉甫为界,同由路克地区为海湾泻湖区,七美干至和什拉甫为台地至台地边缘的碳酸盐岩沉积区,和什拉甫至普司格为碳酸盐岩与碎屑岩混合沉积区;成岩环境有浅海海底成岩环境、潮坪成岩环境、大气淡水成岩环境和埋藏成岩环境;因成岩白云石化作用形成的细晶白云岩伴生的晶间孔隙与因混合白云石化作用形成的粉晶砂屑白云岩、泥晶粉晶腹足云灰岩被溶蚀产生的粒内孔隙和粒间孔隙皆为较好的储层类型;评价结果显示:喀什凹陷卡拉塔尔组碎屑岩储层大部分具有超低孔超低渗的特点,碳酸盐岩储层属于超低孔特低渗储层,叶城凹陷卡拉塔尔组为特低孔特低渗储层。

Depositional Characteristics and Forcast and Evaluation to Kalataer Formation Reservior in Front of Kunlun Mountain in the Southwest of Tarim Basin

Located in front of Kunlun Mountain and southwest margin of Tarim Basin,Kalataer Formation of Paleogene is a heavy mixed layer of carbonate rock and clastic rock,being distributed over the area of Kasa to the west and Keliyang,Yecheng to the east.Kalataer Formation contains 3 large scale tide transgression-tide regression,or 3 microcycles.The depositonal setting in this area can be divided into 3 kinds with Tonyouluke and Heshilafu being the boundary.Tonyouluke was lagoon area.Area from Qimeigan to Heshilafu was platform facies to platform edge facies with carbonate rock deposited.Area from Heshilafu to Pusige was a mixed sedimentary province of carbonate rock and clastic rock.The diagenetic environment includes shallow water diagenetic environment,tide flate diagenetic environment,shallow water and air water compound diagenetic environment,air water diagenetic environment and burial diagenetic environment.Aplitic dolomite with intercrystal pore was developed from diagenetic dolomitization,together with crystal psammitic dolomite and micrite-crystal gastropodus dolomitic limestone with intraparticle pore.Interparticle pore developed from doroga dolomitization becomes the preferable reservoir.The evaluation result displays that the carbonate resevoir of Kalataer Formation in Kasa Depression belongs to mesoporosity and low permeable reservoir,and Kalataer Formation in Yecheng Depression is low porosity and low permeable reservoir.