吉林探区X水平井青一段压裂微地震监测解释实例

An example of microseismic monitoring interpretation of fracturing in Qing1 Member of X horizontal well in Jilin exploration area

为了准确解释微地震事件的时空分布特征,综合评价压裂改造效果,精细认识储层性质,针对微地震监测解释数据不够综合以及吉林探区X水平井微地震监测压裂评价的需求,综合微地震信号时差特征、震级属性、储层沉积特征、砂体展布特征、三维地震数据和测井解释数据等资料,对微地震监测结果进行解释,准确评价压裂改造效果,总结微地震与储层的关系。研究结果表明:宏观上,X水平井压裂裂缝方向与砂体展布方向基本一致,且靠近物源一侧压裂裂缝长,微地震事件数量多,说明X水平井压裂裂缝受储层沉积和砂体展布特点控制;局部上,X井压裂裂缝的长度非对称性和方向变化大,精细描述了储层的横向非均质性,说明压裂裂缝长的位置储层脆性高,泥质含量更低,利于压裂。纵向上,压裂裂缝高度偏大,说明X井目的层上下的大套泥岩层没有起到纵向阻挡作用;测井解释成果显示的油气富集区域压裂缝网规模相对更大,微地震事件数量相对更多,微地震震级相对更大。该研究结果对该探区后期井位部署和压裂具有指导意义。

In order to accurately explain the temporal and spatial distribution characteristics of microseismic events,comprehensively evaluate the fracturing effect and finely understand the reservoir properties,in view of the insufficient comprehensiveness of microseismic monitoring and interpretation data and the needs of microseismic monitoring and fracturing evaluation of X horizontal well in Jilin exploration area,comprehensive microseismic signal time difference characteristics,magnitude attributes,reservoir sedimentation characteristics,sand body distribution characteristics,interpret the microseismic monitoring results with 3D seismic data and logging interpretation data,accurately evaluate the fracturing effect,and summarize the relationship between microseismic and reservoir.The research results show that:macroscopically,the fracturing fracture direction of X horizontal well is basically consistent with the distribution direction of sand body,and the fracturing fracture near the material source side is long and there are manymicroseismic events,indicating that the fracturing fracture of X horizontal well is controlled by the characteristics of reservoir deposition and sand body distribution;Locally,the length asymmetry and direction change of fracturing fracture in well X are large,which accurately describes the transverse heterogeneity of the reservoir,indicating that the position where the fracturing fracture is long has high reservoir brittleness and lower shale content,which is conducive to fracturing.Vertically,the fracturing fracture height is too high,indicating that a large set of mudstone layers above and below the target layer of well X do not play a role in vertical blocking;The logging interpretation results show that the scale of pressure fracture network in oil and gas enrichment area is relatively larger,the number of microseismic events is relatively more,and the microseismic magnitude is relatively larger.The research results of this paper can provide guidance for well location deployment and fracturing in the later stage of the exploration area.