煤炭工程 ›› 2019, Vol. 51 ›› Issue (6): 6-10.doi: 10.11799/ce201906002

• 专题论坛 • 上一篇    

平顶山东北部矿区地应力发育特征及其对煤储层压力、渗透率的控制作用

王晓彬,赵晶,张志荣,李海涛   

  1. 煤炭科学技术研究院有限公司
  • 收稿日期:2018-12-04 修回日期:2019-02-24 出版日期:2019-06-20 发布日期:2019-07-05
  • 通讯作者: 王晓彬 E-mail:117206561@qq.com

Characteristics of in-situ stress and its effect on pressure and permeability of coal reservoirs in northeastern Pingdingshan mining area

  • Received:2018-12-04 Revised:2019-02-24 Online:2019-06-20 Published:2019-07-05
  • Contact: wang xiaobin E-mail:117206561@qq.com

摘要: 为研究平顶山东北部区域地应力对煤储层压力、渗透率的控制作用,依据煤层气井水力压裂和试井工程试验资料,采取水力致裂手段获取地应力的方法,研究了平顶山东北部矿区地应力发育特征,分析了地应力对煤储层压力、渗透率的控制作用。研究表明现今地应力场总体上以水平应力为主,属于典型的构造应力场类型,且总体应力场特征为高倾角断层或裂隙发育|最大水平主应力、最小水平主应力、侧压系数和侧压比均随埋深的增加而线性增加|埋深约在682m时,地应力类型发生转换,地应力类型在垂向的转变原因主要受平顶山矿区多期构造运动所引起的地应力叠加的结果|煤储层压力随着最小水平主应力、垂向应力、有效应力和主应力差的增加呈现增大趋势|渗透率随着主应力差、最大水平有效主应力和最小水平有效主应力关系以负指数形式呈现降低趋势。研究认为构造应力集中区域、低渗透率分布区域是煤层气压裂等储层改造和井下煤层增透卸压工程重点布置区域。

关键词: 平顶山东北部矿区, 地应力, 储层压力, 渗透率

Abstract: In order to study the effect of in-situ stress on the pressure and permeability of coal reservoir in the Northeast of Pingding Shan mining area , the method of obtaining in-situ stress by hydraulic fracturing is adopted based on the test data of hydraulic fracturing and well test engineering in coal-bed methane wells, the characteristics of in-situ stress development in the northern mining area of Pingdingshan are studied, and the influence of in-situ stress on the pressure and permeability of coal reservoir is analyzed. The study shows that the present in-situ stress field is mainly horizontal stress and belongs to the typical type of tectonic stress field, and the overall stress field is characterized by high dip fault or fracture development; the maximum horizontal principal stress, minimum horizontal principal stress, lateral pressure coefficient and lateral pressure ratio increase linearly with the increase of buried depth.Buried depth is about 682 m geostress type conversion, the geostress type in the vertical transformation is mainly caused by the Pingdingshan mining area multi-stage tectonic movement of the results of stress superposition;The pressure of coal reservoir increases with the increase of minimum horizontal principal stress ,d vertical stress, effective principal stress and principal stress difference. The permeability of coal reservoir decreases with principal stress difference, maximum horizontal effective principal stress and minimum horizontal effective principal stress in negative exponential form.It is the key layout area for coal bed gas fracturing and other reservoir reconstruction and underground coal seam permeability increasing and pressure relief engineering.