{"title":"Application of Multiple Diagnostic Plots to Identify End of Linear Flow in Unconventional Reservoirs","authors":"H. Pratikno, W. J. Lee, Cesario K. Torres","doi":"10.2118/205906-ms","DOIUrl":null,"url":null,"abstract":"\n This paper presents a method to identify switch time from end of linear flow (telf) to transition or boundary-dominated flow (BDF) by utilizing multiple diagnostic plots including a Modified Fetkovich type curve (Eleiott et al. 2019). In this study, we analyzed publicly available production data to analyze transient linear flow behavior and boundary-dominated flow from multiple unconventional reservoirs.\n This method applies a log-log plot of rate versus time combined with a log-log plot of rate versus material balance time (MBT). In addition to log-log plots, a specialized plot of rate versus square root of time is used to confirm telf. A plot of MBT versus actual time, t, is provided to convert material balance time to actual time, and vice versa. The Modified Fetkovich type curve is used to estimate decline parameters and reservoir properties. Applications of this method using monthly production data from Bakken and Permian Shale areas are presented in this work.\n Utilizing public data, our comprehensive review of approximately 800 multi-staged fractured horizontal wells (MFHW) from North American unconventional reservoirs found many of them exhibiting linear flow production characteristics. To identify end of linear flow, a log-log plot of rate versus time alone is not sufficient, especially when a well is not operated in a consistent manner. This paper shows using additional diagnostic plots such as rate versus MBT and specialized plots can assist interpreters to better identify end of linear flow. With the end of linear flow determined for these wells, the interpreter can use the telf to forecast future production and estimate reservoir properties using the modified type curve.\n These diagnostic plots can be added to existing production analysis tools so that engineers can analyze changes in flow regimes in a timely manner, have better understanding of how to forecast their wells, and reduce the uncertainty in estimated ultimate recoveries related to decline parameters.","PeriodicalId":10965,"journal":{"name":"Day 3 Thu, September 23, 2021","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Day 3 Thu, September 23, 2021","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.2118/205906-ms","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
This paper presents a method to identify switch time from end of linear flow (telf) to transition or boundary-dominated flow (BDF) by utilizing multiple diagnostic plots including a Modified Fetkovich type curve (Eleiott et al. 2019). In this study, we analyzed publicly available production data to analyze transient linear flow behavior and boundary-dominated flow from multiple unconventional reservoirs.
This method applies a log-log plot of rate versus time combined with a log-log plot of rate versus material balance time (MBT). In addition to log-log plots, a specialized plot of rate versus square root of time is used to confirm telf. A plot of MBT versus actual time, t, is provided to convert material balance time to actual time, and vice versa. The Modified Fetkovich type curve is used to estimate decline parameters and reservoir properties. Applications of this method using monthly production data from Bakken and Permian Shale areas are presented in this work.
Utilizing public data, our comprehensive review of approximately 800 multi-staged fractured horizontal wells (MFHW) from North American unconventional reservoirs found many of them exhibiting linear flow production characteristics. To identify end of linear flow, a log-log plot of rate versus time alone is not sufficient, especially when a well is not operated in a consistent manner. This paper shows using additional diagnostic plots such as rate versus MBT and specialized plots can assist interpreters to better identify end of linear flow. With the end of linear flow determined for these wells, the interpreter can use the telf to forecast future production and estimate reservoir properties using the modified type curve.
These diagnostic plots can be added to existing production analysis tools so that engineers can analyze changes in flow regimes in a timely manner, have better understanding of how to forecast their wells, and reduce the uncertainty in estimated ultimate recoveries related to decline parameters.
本文提出了一种方法,通过利用包括修正Fetkovich型曲线(Eleiott et al. 2019)在内的多个诊断图来识别从线性流(telf)到过渡或边界主导流(BDF)的切换时间。在这项研究中,我们分析了公开可用的生产数据,以分析多个非常规油藏的瞬态线性流动行为和边界主导流动。该方法应用速率与时间的对数-对数图结合速率与物料平衡时间(MBT)的对数-对数图。除了对数-对数图之外,还使用速率与时间平方根的专门图来确认telf。提供了MBT与实际时间的关系图t,用于将物料平衡时间转换为实际时间,反之亦然。采用修正Fetkovich型曲线估计递减参数和储层物性。该方法应用于Bakken和Permian页岩地区的月度生产数据。利用公开数据,我们对来自北美非常规油藏的约800口多级压裂水平井(MFHW)进行了综合评估,发现其中许多井表现出线性流动生产特征。为了确定线性流动的结束,单靠速率与时间的对数-对数图是不够的,特别是当一口井的作业方式不一致时。本文表明,使用额外的诊断图,如比率与MBT和专门的图,可以帮助口译员更好地识别线性流的末端。在确定了这些井的线性流动结束后,解释器可以使用telf预测未来产量,并使用修改后的类型曲线估计储层性质。这些诊断图可以添加到现有的生产分析工具中,以便工程师能够及时分析流动状态的变化,更好地了解如何预测他们的井,并减少与递减参数相关的估计最终采收率的不确定性。