二连盆地白音查干凹陷下白垩统腾格尔组滑塌-浊流沉积特征——以达49井为例

发布时间：2018-03-16 16:10

本文选题：二连盆地　切入点：白音查干凹陷　出处：《石油学报》2017年07期 　论文类型：期刊论文

【摘要】：为厘清白音查干凹陷达49井附近下白垩统腾格尔组下段发育的地层厚度异常体的空间形态、形成机制、形成条件、物质来源等,以利于白音查干凹陷的地层-岩性油气藏勘探,综合运用地层对比、地震反射、钻井岩心和测井数据等资料,主要对其空间发育、沉积构造、结构组分和测井曲线等沉积特征进行了较深入的研究。结果表明该地层厚度异常体主要是由其中的薄层粉—细砂岩叠加造成,在空间上呈透镜状,并与达尔其辫状河三角洲前缘相连接;滑塌砂体中大量发育包卷变形层理及呈拉长状和撕裂状等不规则塑性变形泥砾,其砂体底部冲刷面发育;浊积砂体中大量发育正粒序层理及液化砂岩脉构造,其砂体底部槽模和重荷模较发育。进一步推测白音查干凹陷达49井附近下白垩统腾格尔组下段发育的地层厚度异常体主要为达尔其辫状河三角洲前缘砂体在地震作用触发下发生滑塌,并随着滑塌块体在重力搬运过程中水体的不断加入而逐步转变为浊流沉积;滑塌-浊流沉积形成的前提条件为地形坡度大和具一定的外界触发机制,必要条件为深水滞水环境(形成于湖侵期)和充沛的物源。该滑塌-浊流不发育固定的补给水道,运移距离短,所形成的浊积体规模小、厚度薄,且呈较孤立的透镜状和舌状等,但其数量多、分布广,且靠近烃源岩,只要其具一定的累计厚度,则易于形成岩性油气藏的有利富集带。
[Abstract]:In order to clarify the spatial form, formation mechanism, formation condition and material source of the abnormal formation thickness developed in the lower member of the Lower Cretaceous Tengger formation near well D49 of Baiyinchagan Sag, so as to facilitate the exploration of stratigraphic-lithologic reservoirs in Baiyinchagan sag. Synthetically using data such as stratigraphic correlation, seismic reflection, drilling core and logging data, mainly for their spatial development, sedimentary structure, The sedimentary characteristics such as structural components and logging curves have been studied in depth. The results show that the anomalous body of formation thickness is mainly caused by the superposition of thin siltstone and fine sandstone, and is lenticular in space. It is connected with the front edge of the Dar's braided river delta, and a large number of ductile gravels are developed in the landslide sand body with irregular plastic deformation such as elongate and tear shape, and the scour surface at the bottom of the sand body is developed. In the turbidite sand body, there are a lot of normal grain sequence bedding and liquefaction sandstone vein structure. It is further speculated that the formation thickness anomaly developed in the lower member of the Lower Cretaceous Tengger formation near well Da-49 in Baiyinchagan Sag is mainly the Dar's braided river delta front sand body in the earthquake. The collapse occurs under the trigger of the action, With the continuous addition of the water body in the gravity transport process, the landslide block is gradually transformed into turbidite deposition, and the precondition for the formation of the slough-turbidite deposit is the large terrain slope and the external triggering mechanism. The necessary conditions are the deep-water stagnant environment (formed during the transgression of the lake) and abundant provenance. The slough-turbidity flow does not develop a fixed recharge channel, the migration distance is short, and the turbidite formed is small in size and thin in thickness. But it is large in quantity, wide in distribution and close to the source rock. As long as it has a certain accumulative thickness, it is easy to form a favorable enrichment zone of lithologic reservoirs.
【作者单位】：重庆科技学院石油与天然气工程学院;成都理工大学油气藏地质及开发工程国家重点实验室;中国石油化工股份有限公司中原油田分公司物探研究院;
【基金】：重庆市科委前沿与应用基础研究(一般)项目(cstc2014jcyjA90022) 重庆科技学院科研基金项目(CK2016B14)资助
【分类号】：P618.13

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