柴达木盆地英西地区水平井体积改造及缝网预测技术研究

Horizontal well volume reconstruction and fracture pattern prediction technology in the Yingxi area of Qaidam Basin

了解柴达木盆地英西41井区水平井体积压裂效果和人工裂缝发育情况,评价储层改造的有效性和天然裂缝带对储层改造的影响,对英西地区的储层再认识和压后求产至关重要。目前存在对人工裂缝网络认知不清楚和天然裂缝对人工裂缝的影响程度认识不清楚的问题。储层改造方案采用可溶桥塞套管多簇多段体积压裂工艺,利用微地震裂缝网络监测成像技术实时监测和评价天然裂缝带对储层改造效果的影响程度,并现场实时调整合理的压裂施工参数,微地震和地震属性联合解释评估天然裂缝对储层改造的影响以及天然裂缝与人工裂缝的关系,解决了人工裂缝网络认识不清楚的问题。结果表明,天然裂缝带对微地震事件响应特征和储层改造效果有影响。在水平井体积压裂改造下,裂缝网络成像显示研究区S1井人工网络与天然裂缝带相互沟通,并形成了复杂裂缝网络,增大了流体渗流通道,达到了储层改造的目的,压后投产产油量较高,为研究区增储上产和长期高效稳定开发提供了技术支撑。

The volume fracturing effect and artificial fracture development of horizontal wells in Yingxi 41 well block of Qaidam Basin is essential for the study of reservoir and output calculation.Reservoir reconstruction schemes adopt a multi-cluster and multi-stage volume fracturing process with soluble bridge plug casing.The impact of natural fracture zone on reservoir reconstruction effect is monitored and evaluated in real time through microseismic fracture monitoring network imaging technology,which can adjust reasonable fracturing construction parameters in real time on site.The joint interpretation of microseismic and seismic attributes was used to evaluate the impact of natural fractures on reservoir reconstruction and analyze the relationship between natural and artificial fractures to clarify artificial fracture networks.The results showed that natural fracture zones have an impact on the response characteristics of microseismic events and the effect of reservoir reconstruction.Under volume fracturing reconstruction of horizontal wells,the fracture network imaging showed that the artificial network of well S1 in the study area has a relationship with the natural fracture zone and forms a complex fracture network,increasing the fluid flowing path and achieving the purpose of reservoir reconstruction.The oil production after fracturing is high,providing technical support for increasing reserves and production and long-term,efficient,and stable development in the study area.Fracture monitoring technology has been effectively developed and used in major oil and gas fields in China to achieve good results,contributing substantially to the effective development of unconventional oil and gas reservoirs.The application of seismic and microseismic joint interpretation technology is becoming increasingly critical,especially in fault and natural fracture developed reservoirs,and pre-fracturing prediction can be used to prevent casing deformation during fracturing,providing reasonable suggestions in advance.Real-time performance of fracture monitoring technology,which is another characteristic of modified technology,is becoming increasingly important.Fracture monitoring technology is developing towards the idea of integration,and its application prospects and problem-solving ability are very important.