石油与天然气地质 ›› 2019, Vol. 40 ›› Issue (6): 1324-1332.doi: 10.11743/ogg20190616

• 方法技术 • 上一篇    下一篇

一种考虑气藏特征的页岩含气量计算方法——以四川盆地及其周缘焦页1井和彭页1井为例

李东晖1,2,3, 聂海宽1,2,3   

  1. 1. 页岩油气富集机理与有效开发国家重点实验室, 北京 100083;
    2. 中国石化 石油勘探开发研究院, 北京 100083;
    3. 中国石油化工集团公司 页岩油气勘探开发重点实验室, 北京 100083
  • 收稿日期:2018-08-14 修回日期:2019-08-09 出版日期:2019-12-28 发布日期:2019-10-15
  • 第一作者简介:李东晖(1991-),男,工程师,非常规油气开发。E-mail:lidh.syky@sinopec.com。
  • 基金项目:
    国家科技重大专项(2016ZX05061-001);国家自然科学基金项目(41202103,41872124)。

A new method to calculate shale gas content based on gas reservoir characterization-A case study of Wells JY 1 and PY 1 in Sichuan Basin and its surrounding areas

Li Donghui1,2,3, Nie Haikuan1,2,3   

  1. 1. State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development, Beijing 100083, China;
    2. Petroleum Exploration and Production Research Institute, SINOPEC, Beijing 100083, China;
    3. Key Laboratory of Shale Oil and Gas Exploration & Production, SINOPEC, Beijing 100083, China
  • Received:2018-08-14 Revised:2019-08-09 Online:2019-12-28 Published:2019-10-15

摘要: 损失气含量是页岩气含气量的重要组成部分,是页岩气总气量的确定、页岩气资源量和储量计算的重要参数。基于煤层气岩心解吸测试中采用的损失气计算方法——USBM方法及其改进方法不能真实反映页岩气藏损失气含量。综合考虑页岩气藏特征、储层类型及特征、孔隙结构、孔喉大小、气藏压力、取心时间、解吸气含量和解吸时间等因素,重点考虑了钻遇岩心时的瞬间散失气量和解吸速率,提出了一种页岩损失气含量和含气量的计算方法。以超压页岩气藏JY1井和常压页岩气藏PY1井为例,采用该方法计算JY1井下部优质页岩层段的总含气量为6.87~9.02 m3/t,平均7.47 m3/t,上部页岩层段的总含气量为3.25~3.82 m3/t,平均3.64 m3/t;PY1井下部优质页岩层段的总含气量为3.18~4.29 m3/t,平均3.83 m3/t;上部页岩层段的总含气量为1.67~2.28 m3/t,平均1.94 m3/t。明显高于常用算法计算的总含气量数值。采用理论计算法和依据焦石坝页岩气井生产特征计算法两种方法对本文提出的页岩含气量计算方法进行了验证,吻合度较好。研究成果为页岩气藏、尤其是超高压页岩气藏含气量、储量计算和产能评价提供理论依据和计算方法支撑。

关键词: 损失气, 孔隙结构, 气藏压力, 含气量, 页岩气, 焦石坝地区, 四川盆地

Abstract: Lost gas content is an integral part of the total shale gas content,and also a significant parameter for determination of total shale gas volume and evaluation of shale gas in place and reserves.However,the USBM method,the existing calculation method of lost gas content based on core desorption test of coal-bed methane,along with its modified methods,cannot truly reflect the loss of gas content in shale gas reservoirs.Focusing on the instantaneous lost gas content and desorption rate during the core-drilling,we proposed a new method to calculate the lost gas content and the total shale gas content after performing a series of analyses,including characteristics of shale gas reservoirs,reservoir types,pore structure,pore throat size,gas reservoir pressure,coring time,desorbed gas content,and desorption time.The Well JY1 in the shale gas reservoir of overpressure and Well PY1 in the gas reservoir of normal pressure were taken as examples in the study.In applying the new method to Well JY1,we figured out the total gas content of the high-quality lower shale interval,varying from 6.87 m3/t to 9.02 m3/t with an average of 7.47 m3/t,and the total gas content of the upper shale interval,varying from 3.25 m3/t to 3.82 m3/t with an ave-rage of 3.64 m3/t; while in the Well PY1,the total gas content of the high-quality shale intervals ranges from 3.18 m3/t to 4.29 m3/t with an average of 3.83 m3/t,and the total gas content of the upper shale layers ranges from 1.67 m3/t to 2.28 m3/t with an average of 1.94 m3/t.Obviously,these values above are significantly higher than those calculated by using conventional methods.The new method proposed above has been verified by both the theoretical calculation method and performance-based calculation method with the shale gas production wells in Jiaoshiba area as examples.For shale gas reservoirs,especially the overpressured shale gas reservoirs,the new method highlighted in the study serves to provide not only a great theoretical support but also a practical way to calculate shale gas content and reserves,so as to evaluate the reservoir productivity.

Key words: lost gas, pore structure, gas reservoir pressure, gas content, shale gas, Jiaoshiba area, Sichuan Basin

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