吉木萨尔页岩油“甜点”预测方法

Shale Oil“Sweet-Spot”Prediction in Jimusar Sag

针对吉木萨尔凹陷二叠系芦草沟组页岩油"甜点"变化快、水平井钻遇率低等问题,从测井和地震2个方面展开分析。纵向上,将二叠系芦草沟组页岩油"甜点"分为上"甜点"和下"甜点"2个部分,类型上划分为Ⅰ、Ⅱ、Ⅲ共3类,并明确了上、下"甜点"的地震反射特征。在此基础上,通过敏感参数交会分析,确定了基于地震地质统计学模拟的"甜点"预测方法,预测精度得到了有效提高,预测"甜点"识别厚度由前期的20 m提至6 m,"甜点"钻遇率由87%提高至92%以上,从而实现了完钻水平井规模压裂及高效开发。通过上述研究,形成了一套针对陆相页岩油"甜点"的地震预测方法,并在生产实践中得到了验证,为页岩油水平井高效开发提供了技术支撑。

Logging and seismic data were analyzed to improve the significant variation of shale oil“sweet-spot”,horizontal well drilling encounter ratio and other challenges in the Permian Lucaogou Formation of Jimusar Sag.The shale oil reservoir in the Permian Lucaogou Formation was divided into two parts and three categories.The two parts include the upper“sweet-spot”and the lower“sweet-spot”,and the three categories include Category-I,Category-II and Category-III.The seismic reflection patterns of the upper“sweet-spot”and the lower“sweet-spot”were also provided.Sensitive parameter intersection analysis was completed to propose a“sweet-spot”prediction method based on seismic geo-statistical simulation.The prediction accuracy has been effective improved The thicknes of the“sweet-spot”was predicted to increase from 20 meters to 6 meters and the corresponding“sweet-spot”encounter ratio has been increased from 87%to 92%,which realizes the large-scale fracturing and efficient development with horizontal wells.A set of seismic prediction for continental shale oil sweet-spot was proposed and verified in the production practice.This research could provide certain technical reference for the efficient development of shale oil resource with horizontal well.