石油学报 ›› 2019, Vol. 40 ›› Issue (11): 1358-1367.DOI: 10.7623/syxb201911006

• 油田开发 • 上一篇    下一篇

考虑时变效应的致密气井产能评价——以延安气田为例

王香增1, 冯东2, 李相方2, 严云奎1, 郭向东1, 乔向阳1, 薛波1, 马骋1, 王泉波1, 雷开宇1, 张涛2, 姚天福2, 赵文2   

  1. 1. 陕西延长石油(集团)有限责任公司 陕西西安 710000;
    2. 中国石油大学(北京)石油工程教育部重点实验室 北京 102249
  • 收稿日期:2019-06-04 修回日期:2019-11-04 出版日期:2019-11-25 发布日期:2019-12-07
  • 通讯作者: 王香增,男,1968年12月生,1989年获西安石油学院学士学位,1998年获中国地质大学(北京)博士学位,现为陕西延长石油(集团)有限责任公司总地质师,主要从事石油与天然气勘探开发工作。Email:sxycpcwxz@126.com
  • 作者简介:王香增,男,1968年12月生,1989年获西安石油学院学士学位,1998年获中国地质大学(北京)博士学位,现为陕西延长石油(集团)有限责任公司总地质师,主要从事石油与天然气勘探开发工作。Email:sxycpcwxz@126.com
  • 基金资助:

    国家自然科学基金项目"页岩气有效储渗孔隙跨尺度耦合渗流及产出规律研究"(No.50974128)、国家科技重大专项"陆相页岩气产能评价与采气工艺技术"(2017ZX05039)和陕西延长石油(集团)有限责任公司横向课题"延安致密砂岩气藏经济持续高效开发理论与技术研究"资助。

Productivity evaluation of tight gas well with time-dependent mechanism: a case study of Yan'an gasfield

Wang Xiangzeng1, Feng Dong2, Li Xiangfang2, Yan Yunkui1, Guo Xiangdong1, Qiao Xiangyang1, Xue Bo1, Ma Cheng1, Wang Quanbo1, Lei Kaiyu1, Zhang Tao2, Yao Tianfu2, Zhao Wen2   

  1. 1. Shaanxi Yanchang Petroleum(Group) Co., Ltd., Shaanxi Xi'an 710000, China;
    2. Key Laboratory of Petroleum Engineering, Ministry of Education, China University of Petroleum, Beijing 102249, China
  • Received:2019-06-04 Revised:2019-11-04 Online:2019-11-25 Published:2019-12-07

摘要:

在致密气井的生产过程中,压裂裂缝导流能力、储层流体分布和气水相渗都会不断发生变化,具有时变效应,而传统的产能评价往往忽略了这种效应。针对这一问题,通过建立考虑裂缝导流能力时变效应和储层气水相渗时变效应的渗流数学模型,评价了时变效应对气井产能的影响。研究结果显示:压裂裂缝导流能力的时变效应增加了流体流动阻力,缩短了气井的稳产期;气井生产过程中,除了流体和岩石本身的膨胀能外,气水相渗的时变效应能够减小束缚水饱和度,使得部分束缚水转化为可动水,增大了水相渗透率,减小了气相渗透率,加快气井见水并增大气井产水量,促使气井递减提早出现。延安气田的实际气井生产表明,不考虑时变效应预测的稳产期偏长,预测的产水量远低于实际气井的产水量,时变效应对气井生产的影响不可忽略,结合延安气田开发实际还需进一步研究在立体井网开发模式下考虑时变效应的气井产能模型。

关键词: 致密气, 裂缝导流能力, 气水分布, 时变性, 气井产能

Abstract:

In the production process of tight gas wells, the fracture conductivity, reservoir fluid distribution and gas-water relative permeability will vary with time. However, the traditional models always ignore these effects. Based on this, the time-dependent factors, including fracture conductivity and relative permeability are introduced to construct the seepage model for gas production. Subsequently, the simulations are conducted to analyze the effects of time-dependent mechanisms on gas well productivity. Results show that time-dependent fracture conductivity will accelerate the gas production decline because the fluid flow towards the wellbore will consume more energy. In the production process, besides the expansion of rock and fluids, the pressure gradient can decrease the irreducible water saturation and promote the migration of irreducible water, resulting in the increase of water permeability and the decrease of gas permeability. This effect will reduce the period of stable gas production and increase the water production. The production of a gas well in Yan'an gasfield indicated that ignoring the time-dependent effects will severely underestimate the water production and overrate the period of table gas production. Finally, according to the development mode of Yan'an gasfield, the gas well productivity model with considering the time-dependent factors for stereoscopic well pattern should be further studied.

Key words: tight gas, fracture conductivity, gas-water distribution, time-dependent mechanism, gas well productivity

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