多分量裂缝预测技术研究及其在川南页岩气工区的应用

Research and application of multi-component fracture prediction technology in shale gas area

与常规油气相比,页岩中普遍含气,但是单井的产量变化大,通过改造形成裂缝网络的页岩气井才具有工业开发价值。目前,页岩裂缝预测的方法较多,大多数是基于纵波地震资料的,而利用多分量地震资料预测裂缝发育区仍是研究人员探索和努力的方向。这里首次运用转换横波地震资料对页岩气的裂缝发育情况进行预测研究。首先,利用转换波模型正演,结合多波地震资料对比识别页岩的小断裂、小断层。其次,通过基于横波分裂特性的裂缝预测技术对高角度的裂缝走向和密度进行预测。通过四川盆地实际资料应用表明,多分量裂缝预测技术能够有效识别页岩气的裂缝发育情况,多分量裂缝预测效果明显优于纵波叠前裂缝预测,成果更加合理。

Compared with conventional oil and gas,shale generally contains gas,but the output of a single well varies greatly.Generally,only shale gas wells that form a complex fracture network through transformation have more excellent industrial development value.At present,there are many methods to predict shale fractures based on P-wave seismic data,while predicting fracture development areas using multi-component seismic data is still the direction of researchers'exploration and efforts.This paper uses converted wave seismic data to predict the development of shale gas fractures for the first time.First,the converted wave model is used for forward modeling,combined with multi-wave seismic data to compare and identify minor fractures and faults in shale.Secondly,the shear wave splitting technology predicts the crack trend and density at high angles.The application of actual data in the Sichuan Basin shows that the fracture prediction technology of converted waves can effectively identify the fracture development of shale gas,and the prediction results are consistent with the results of imaging logging prediction with high accuracy.