摘要: |
伊朗雅达油田Kazhdumi沥青层孔隙压力求取值波动大,随钻井液密度的增加沥青溢出量不减少反而增加。为了解释这反常现象,提出封闭地质空间内流体与井筒通过置换性双向流动形成的泛井筒空间的概念,建立地层沥青与井筒钻井液置换性双向流动的机制模型;采用室内沥青置换模拟试验,验证钻井液置换沥青速度和钻井液与沥青的密度差呈线性增加关系。结果表明,密闭地质流体空间中的置换性双向流动是导致沥青层孔隙压力波动的根本原因。 |
关键词: 沥青层 置换 双向流动 泛井筒空间 地层孔隙压力波动 |
DOI:10.3969/j.issn.1673-5005.2017.06.010 |
分类号: |
基金项目:"十三五"国家科技重大专项(2016ZX05033-004);中石化科技部项目(P16014) |
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Asphalt displacement mechanism and pore pressure fluctuation in Yadavaran Oilfield, Iran |
LU Baoping, HOU Xutian, XING Shubin
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Research Institute of Petroleum Engineering, SINOPEC, Beijing 100101, China
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Abstract: |
It has observed that the pore pressure of the Kazhdumi asphalt formation fluctuates greatly in Yadavaran Oilfield of Iran, and asphalt spillage increases instead of decreasing when the density of drilling fluid goes up. To explain this abnormal phenomenon, a concept of extensive wellbore formed by displacement bidirectional flow between the fluids in the enclosed geological space and wellbore was presented. A mechanism model of bidirectional displacement flow between asphalt in formation and drilling fluid in wellbore was figured out. Laboratory simulation experiments show that, as the density difference between drilling fluid and asphalt increases, the asphalt displacement rate increases proportionally. The results indicate that bidirectional displacement flow in enclosed geological fluid space is the essential cause of the pore pressure fluctuation in the asphalt formation. |
Key words: asphalt formation displacement bidirectional flow extensive wellbore space formation pressure fluctuation |