东营凹陷高89地区二氧化碳驱油及封存过程中断层纵向安全性评价体系

Evaluation on vertical safety of fault during carbon dioxide flooding and sequestration in the Gao89 area of Dongying sag

东营凹陷高89地区断层按活动期次可划分为一期活动断层、同生活动断层和多期活动断层3类,其活动停止时间依次变晚,纵向安全性依次降低;断层延伸与盖层的配置关系可划分为嵌入式、下断式和断穿式3种模式,其纵向盖层的结构完整性依次变差,纵向安全性依次降低;断层断距与直覆盖层厚度的配置关系可划分为顶部完整型、盖层见面型和盖层相隔型3种类型,其直覆盖层的完整性依次变差,纵向安全性依次降低.依据断层活动期次、断层延伸与盖层的配置关系、断层断距与直覆盖层厚度的配置关系、盖层粘结段厚度和断层倾角,建立高89地区断层纵向安全性综合评价体系,对研究区二氧化碳驱油及封存过程中断层的纵向安全性进行了综合评价.研究结果表明,高89地区断层主要发育嵌入式和下断式模式,发育顶部完整型和盖层见面型2种类型,断层倾角为40°~65°,综合分析认为高89地区断层纵向安全性较高.

The faults were divided into single-stage active fault,growth fault and multi-stage active fault according to the fault activity period in the Gao89 area of Dongying sag. The fault activity of the three types ended in the order mentioned above,so their vertical safety becomes poorer correspondingly. According to the allocation relationship between the regional seal and the vertical extension of fault,the faults were divided into embedded type,lower broken type and broken through type,and the seal completeness of them decrease in the order,so the vertical safety becomes poorer correspondingly. According to the allocation relationship between the fault throw and the thickness of the direct seal,the faults were divided into intact top seal type,seal connected type and seal apart type,and the completeness of their direct seals decrease in the order,so their vertical safety become poorer correspondingly. The comprehensive evaluation system was established to evaluate carbon dioxide flooding and the vertical safety of the fault during carbon dioxide sequestration through analyzing fault activity periods,the allocation relationship between the regional seal and the vertical extension of fault,the allocation relationship between the fault throw and the thickness of the direct seal,the bonding section thickness of the direct seal and the fault dip in the Gao89 area. The results show that the allocation relationships between the regional seals and the vertical extension of faults are mostly embedded type and lower broken type. The allocation relationships between the fault throw and the thickness of the direct seal are the intact top seal type and the seal connected type without the seal apart type. The fault dip is between 40° and 65°. According to the study result,the vertical safety of faults are high in the Gao89 area.