基于水击压力监测的压裂暂堵有效性评价方法

An Evaluation Method for Fracturing Temporary Plugging Based on Water Hammer Pressure Monitoring

  • 摘要: 暂堵有效性是暂堵压裂作业效果的重要评价指标,但目前缺少评价暂堵压裂作业暂堵有效性的方法,而基于水击压力波的井下裂缝监测技术可以准确捕获压后井下的多簇裂缝响应。因此,提出了一种基于水击压力倒谱响应的暂堵有效性评价方法(WHBEM)。首先,基于暂堵前后井下裂缝的水击倒谱响应,提出一种基于各簇响应能量比例变化的暂堵效率计算方法。其次,提出一种基于裂缝能量响应比例变化趋势的惩罚函数,用于修正各簇裂缝的暂堵效率。最后,取各簇修正后暂堵效率平均值作为该段暂堵有效率,并提出了暂堵效果评价标准。利用WHBEM评价了新疆某碳酸盐凝析气井共9段暂堵压裂的暂堵效果,结果显示案例井平均暂堵有效率71%,暂堵效果优秀段和良好段分别为5段和4段,案例井整体暂堵效果优秀。同时,WHBEM的计算结果与Erf函数计算结果的相关系数为0.57,表现出相同的趋势性,且与各段施工过程中暂堵到位升压情况相吻合。研究表明,WHBEM从各簇裂缝水击响应特征变化幅度和趋势2方面量化计算暂堵效率,暂堵评价结果更加客观准确,可为井场暂堵作业的实时调控提供有效的指导。

     

    Abstract: The effectiveness of temporary plugging is one of the important index of temporary-plugging fracturing. However, there is currently a lack of research on temporary-plugging evaluation based on this technology. Downhole fracture monitoring technology based on water-hammer pressure waves can accurately capture the response of multiple fractures in the well after fracturing. Therefore, a temporary-plugging effectiveness evaluation method (WHBEM) based on water-hammer pressure cepstrum is innovatively proposed in this paper. Firstly, based on water-hammer cepstrum response of downhole fractures before and after temporary plugging, a efficiency calculation method based on the change of the energy proportion of each cluster response is proposed. Secondly, a penalty function based on changing trend of the fractures-energy-response ratio is proposed to correct the temporary-plugging efficiency of each fracture. Finally, the average value of the corrected temporary-plugging efficiency of each fracture is taken as the temporary-plugging effectiveness of this section, and an evaluation criterion for plugging performance is established. In this paper, the effect of 9 temporary-plugging-fracturing sections in a carbonate condensate gas well in Xinjiang are evaluated. The results show an average plugging effectiveness of 71% for the case well, with 5 stages rated as excellent and 4 as good, indicating overall excellent performance. Furthermore, the correlation coefficient between the WHBEM and Erf function is 0.57, demonstrating a consistent trend that aligns with the pressure increase observed during the plugging operation in each stage. The research concludes that by quantitatively assessing plugging efficiency through both the magnitude and trend of the water-hammer response of each fracture, the WHBEM provides more objective and accurate evaluation results. This research can offer effective guidance for the real-time control of temporary plugging operations in the field.

     

/

返回文章
返回