CAJ | 학술논문

塔里木盆地大涝坝地区下白垩统巴什基奇克组岩性剖面存在多套隔夹层,对油气藏开发具有较大影响.通过沉积学及高分辨率层序地层学分析表明,沉积环境不同,隔夹层成因、特点和分布规律有较大的差异.浅湖环境形成的Ⅰ_1型隔夹层厚度最大,连续性最好;分流间湾环境形成Ⅰ_2型隔夹层及河道间环境形成的Ⅱ_1型隔夹层厚度较薄,连续性差;泛滥平原环境形成的Ⅱ_2型隔夹层厚度较大,连续性较好.同时,隔夹层的分布规律与其所处中长期基准面旋回背景密切相关.Ⅱ_1型隔夹层分布于中长期旋回上升半旋回中下部,且一般发育于高可容纳空间的短期旋回上升半旋回的上部;Ⅰ_1型、Ⅱ_2型隔夹层在中长期旋回上升半旋回与下降半旋回转换处;Ⅰ_2型隔夹层位于中长期旋回下降半旋回下部.在巴什基奇克组剖面上,由下至上隔夹层厚度大致由薄变厚,在中长期旋回的上升半旋回与下降半旋回转换处隔夹层厚度最大,然后向上隔夹层厚度变薄.
탑리목분지대로패지구하백성통파십기기극조암성부면존재다투격협층,대유기장개발구유교대영향.통과침적학급고분변솔층서지층학분석표명,침적배경불동,격협층성인、특점화분포규률유교대적차이.천호배경형성적Ⅰ_1형격협층후도최대,련속성최호;분류간만배경형성Ⅰ_2형격협층급하도간배경형성적Ⅱ_1형격협층후도교박,련속성차;범람평원배경형성적Ⅱ_2형격협층후도교대,련속성교호.동시,격협층적분포규률여기소처중장기기준면선회배경밀절상관.Ⅱ_1형격협층분포우중장기선회상승반선회중하부,차일반발육우고가용납공간적단기선회상승반선회적상부;Ⅰ_1형、Ⅱ_2형격협층재중장기선회상승반선회여하강반선회전환처;Ⅰ_2형격협층위우중장기선회하강반선회하부.재파십기기극조부면상,유하지상격협층후도대치유박변후,재중장기선회적상승반선회여하강반선회전환처격협층후도최대,연후향상격협층후도변박.
The insulating layers existing in a lithological profile of the Lower Cretaceous Bashijiqike Formation in Tarim Basin have influence on developing reservoirs. The cause of formation, the features and distribution principle are different with the difference of sedimentary environment according to the theory and analysis of sedimentology and high resolution sequence stratigraphy. Type Ⅰ_1 insulating layers formed in shallow lakes are the best in thickness and continuity. Type Ⅰ_2 and Type Ⅱ_1 respectively formed in branch bays and inter-channels are inferior in thickness and continuity. Type Ⅱ_2 developed in flooding plains is better in thickness and continuity. Also, the distribution principle of insulating layers is consanguineously associated with the middle-long term base level cycles where they are located. Type Ⅱ_1 insulating layers are distributed over the middle-lower section of the ascending semi long-middle term cycle and generally develop in the ascending semi-short term cycle in high accommodation. Type Ⅰ_1 and Type Ⅱ_2 ones develop in the transfer level between the ascending and descending semi-long-or-middle term cycles. Type Ⅰ_2 develops in the lower section of the descending semi-middle-long term cycles. The insulating layers are getting thicker from bottom to up in the profiles of Bashijiqike Formation and are the thickest in the transfer level between the ascending and descending semi-cycles of the middle-long term base level cycles, then get thinner upwards.