准噶尔盆地莫索湾地区侏罗系超压预测技术研究

Research on Prediction Technologies for Overpressure in the Jurassic Strata of the Mosuowan Area,Junggar Basin

准噶尔盆地莫索湾地区侏罗系普遍发育超压,实现高精度压力预测不仅有助于提升该地区成藏认识,还能够确保钻井安全。目前常见的超压预测方法普遍直接或间接受到超压成因的影响,其适用范围各不相同。在地质分析的基础上,结合超压段测井响应特征,认为莫索湾地区侏罗系超压成因以深部压力传导为主、黏土矿物转化为辅,欠压实成因对超压的贡献极其有限。进一步根据相关模型的原理,筛选出3种适用于研究区的压力预测模型,分别为Fillippone模型、趋势回归模型和Bowers模型。结合实际应用效果对比,认为在早期无参考井时,适宜使用Fillippone模型进行随钻压力监测;在有少数参考井时,适宜使用Bowers模型;在勘探程度较高研究超压分布特征时,适宜使用趋势回归模型和Bowers模型。

Overpressure is widespread in the Jurassic strata of the Mosuowan area in the Junggar Basin.Achieving precise pressure prediction with high accuracy is crucial for enhancing reservoir formation understanding and ensuring optimal drilling safety.However,existing pressure prediction methods are generally influenced,either directly or indirectly,by the causes of overpressure,leading to variations in their applicability.This study,based on the geological and logging response characteristics of the overpressured section,postulates that overpressure in the Jurassic strata of the Mosuowan area primarily originates from deep pressure transmission,with supplementary contributions from clay mineral transformation,while undercompaction plays a negligible role.Three pressure prediction models were selected:Fillippone,trend regression,and Bowers models.These models were compared for practical applications.In conclusion,the Fillippone model is suitable for early-stage pressure monitoring while drilling without reference wells;the Bowers model is recommended when there are limited reference wells available.In the late exploration stage,both trend regression and Bowers models can be utilized to investigate overpressure distribution.