渤海辽中凹陷构造反转作用下沉积模式认识及应用——以JX油田西块东营组为例

Recognition and application of sedimentary model under tectonic inversion in Liaozhong sag of Bohai Sea——by taking Dongying formation in the west block of JX oilfield as an example

JX油田位于辽东湾辽中凹陷,目的层东营组砂岩厚度大,砂岩百分含量最高可达70%以上,辽中1号断层将其分割成东、西两块。辽中1号断层由两条分段断层组成,属于郯庐走滑断裂带的一部分,因其既具有一定持续性,也具有间歇性,从而使西块在走滑活动期(东营组沉积时期)发生构造反转,并在走滑活动间歇期沉积相对稳定。由于受活动期构造反转影响,间歇期前后沉积模式差异较大,导致同一区域不同层位砂体范围、水体倍数等差异明显,对开发方式和井网部署影响较大。通过对构造活动期次及其影响下的古地貌特征分析,开展各层段沉积模式研究,找到该区域油井低压原因,并进行相应调整井部署,取得了较好开发效果。该方法对于同类型走滑活动下沉积模式研究和开发方式、井网、井位部署,具有一定的指导和借鉴意义。

Located in the Liaozhong sag of Liaodong Bay,the sandstone thickness of JX oilfield in the target Dongying formation is large,and the percentage of sandstone is up to 70%.The oilfield is divided into east and west blocks by Liaozhong No.1 fault which is composed of two segmented zones and belongs to the part of the Tanlu strike slip fault zone.Liaozhong No.1 fault is a strike slip fault whose activity is both continuous and intermittent.Affected by the activity,the west block has tectonic inversion during the strike slip period of the depositional period of the Dongying formation.On the other hand,during the strike slip intermittent period the deposition is relatively stable.Due to the effect of tectonic inversion during the period of activity,the difference of sedimentary modes before and after the intermittent period is larger,which leads to obvious differences in sand body range and water multiple of different layers in the same region,which has a great influence on the development mode and well network deployment.Through the analysis of tectonic activity periods and paleogeomorphic characteristics under the influence,the sedimentary model of each layer is studied,the reasons for the low pressure of oil wells in this area are found,and the corresponding adjustment well deployment is carried out,which has achieved good development results.This method provides a good guidance and reference for the study of sedimentary model and development mode,well pattern and well location deployment under the same type of strike-slip activity.