摘要
钻井液侵入原始地层必将引起井周介质的电阻率的变化,进而使得阵列侧向仪器所测得的视电阻率失真,无法正确对储层流体的性质进行识别,因此研究钻井液侵入对阵列侧向仪器响应的影响具有十分重要的理论与实际价值。利用两项渗流方程结合有限元数值模拟技术,直接对钻井液侵入后的模型模拟阵列侧向测井的响应,定量分析了低侵条件下侵入时间、井柱与地层压力差、泥饼渗透率、含水饱和度、矿化度差异等因素对阵列侧向正演响应研究的影响。结果表明:钻井液侵入严重影响了阵列侧向测井响应,阵列侧向测井在钻井液侵入0.1 d时,4种不同探测模式下的视电阻率值R_(1)、R_(2)、R_(3)、R_(4)相较于未侵入时分别下降了39.8%、30%、24%、17%。钻井液侵入1d、井柱与地层压力差Δpd为2MPa时,R_(1)、R_(2)、R_(3)、R_(4)相较于未侵入时分别下降了31%、23%、17%、8%;在地层含水饱和度达到40%时,R_(1)视电阻率值下降了76%,R_(2)、R_(3)、R_(4)视电阻率值分别下降了60%、56%、40%。
The invasion of drilling fluid into the original formation will cause the change of the resistivity of the media around the well,and then the apparent resistivity measured by the array lateral instrument will be distorted,and the property of reservoir fluid cannot be identified correctly.Therefore,it is of great theoretical and practical value to study the influence of drilling fluid invasion on the response of array lateral instrument.In this paper,two seepage equations combined with finite element numerical simulation technology were used to simulate the response of array lateral logging directly to the model after drilling fluid invasion.The influence of invasion time,pressure difference between well string and formation,mud cake permeability,water saturation and salinity difference on array lateral forward response under low invasion condition was quantitatively analyzed.The results showed that,drilling fluid invasion seriously affected the response of array lateral logging.The apparent resistivity values of R_(1),R_(2),R_(3) and R_(4) under four different detection modes were reduced by 39.8%,30%,24%and 17%respectively compared with those without drilling fluid invasion.When the drilling fluid invaded for one day and the pressure difference between the well string and formationΔPD was 2 MPa,R_(1),R_(2),R_(3) and R_(4) decreased by 31%,23%,17%and 8%respectively compared with those without invasion;when the formation water saturation reached 40%,the apparent resistivity of R_(1) decreased by 76%,R_(2),R_(3) and R_(4) decreased by 60%,56%and 40%respectively.The research results provide a theoretical basis for array lateral logging interpretation to eliminate the influence of drilling fluid invasion.
作者
杜双军
徐思慧
冯加明
张杰
DU Shuang-jun;XU Si-hui;FENG Jia-ming;ZHANG Jie(Key Laboratory of Oil and Gas Resources and Exploration Technology of Ministry of Education,Yangtze University,Wuhan 430100,China;School of Geophysics and Petroleum Resources,Yangtze University,Wuhan 430100,China;Exploration Division of Tarim Oilfield Company,Korla 841000,China;Research Institute of Exploration and Development,PetroChina North China Oilfield Branch,Renqiu 062552,China)
出处
《当代化工》
CAS
2021年第3期631-634,共4页
Contemporary Chemical Industry
基金
国家科技重大专项,古老地层密度、磁化率、电阻率等岩石物性研究(项目编号:2016ZX05004-003-007)
国家自然科学基金项目,地层条件下富有机质页岩电磁响应机理与应用基础研究(项目编号:U1562109)联合资助。
关键词
渗流理论
电磁场理论
数值模拟
阵列侧向测井
Seepage theory
Electromagnetic field theory
Numerical simulation
Array lateral logging
