泵抽式电缆地层测试复合流形模型研究及应用

The Study and Application of Combined Flow Shape Model of Wireline Formation Tester with Pump

泵抽式电缆地层测试是在油气资源评价中快速获得储层的渗透率的技术手段。目前对泵抽式电缆地层测试压力资料分析多采用球形流分析法,而对于大排量泵抽式电缆地层测试器,在薄储层和储层的上下边界,测试流动形态则会从球形流过渡为柱形流,如果仍然采用球形流动解释方法,就会给解释结果带来较大的误差。通过分析泵抽式电缆地层测试储层流动形态,并应用油气层渗流力学理论,推导出了在球形流与柱形流复合流动形态下的渗透率求解模型。选择某油田一口井的电缆地层测试资料为例对该模型进行验证。由于测试目的层为层薄,渗流为球形流与柱形流复合流动形态,采用模型计算得到储层渗透率为46.6×10-3μm2,与该层段取心分析岩心渗透率(56×10-3μm2)接近,证明该渗透率求解模型可行。

Wireline formation tester with pump is a technical way for obtaining reservoir permeability quickly in the process of oil-gas source evaluation.Analytic approach of spherical flow is mostly used for analyzing pressure data of wireline formation test with pump.Testing flowing shape in the thin reservoirs and on the boundary of reservoirs may change from spherical shape to cylinder.The analytic approach of spherical flow will bring large error for high-duty wireline formation tester with pump.After testing flowing shape is analyzed and fluid mechanics in porous media of hydrocarbon reservoirs are applied,model of permeability solution on the compound flowing shape of spherical flow and cylinder flow is derived.The model is verified through wireline formation testing data of one well in certain oilfield.Combined model of spherical and cylinder flow shape at thin bed testing is established.Its reservoir permeability is 46.6×10-3μm2 by the model,close to the core permeability by coring(56×10-3μm2).The model is proved available for permeability solution.