为了预测渗透性砂岩地层的漏失压力，提高钻井的安全性。根据塑性流体的本构方程和毛细管渗流理论，分析了钻井液（宾汉流体）在井壁泥饼带、地层侵入带和原地层孔隙中的流动特性，分别建立了井壁有无泥饼2种情况下的渗漏压力计算模型。利用建立的数学模型，对崖城131 A15井压力衰竭储层段的漏失压力进行了预测，结果表明：井壁上未形成泥饼时，漏失压力当量密度为0.613 kg/L ；井壁上形成厚度1 mm、渗透率小于4×10-5 D的泥饼时，漏失压力当量密度可提高到1.21 kg/L以上。崖城131 A15井钻井施工中，采用密度1.10 kg/L的抗高温Versaclean油基钻井液，没有发生井漏。建立的渗透性砂岩地层漏失压力预测模型，可为渗透性砂岩地层安全钻井提供参考。%In order to predict leak-off pressure in high-permeability sandstone formations and ensure drilling safety ,through analysis of the flow characteristics of drilling fluid in mud cake zone ,invaded zone and in-situ pores ,two calculation models for predicting leak-off pressure were established ,with or without mud cake on wellbore ,according to the constitutive equation of plastic fluid and capillary percolation theo-ry .The leak-off pressure of Well Yacheng 13 1 A15 was predicted by this model ,the results indicate that leak-off pressure equivalent density was 0.613 kg/L in the case of no mud cake on the wellbore ;the leak-off pressure equivalent density was 1.21 kg/L when mud cake formed on the wellbore with the thickness of 1 mm and permeability was less than 4 × 10-5 D .Lost circulation did not occur in the drilling of Well Yacheng 13 1 A15 through adoption of Versaclean high temperature oil-based plugging drilling fluids with a density of 1.10 kg/L .The prediction model for leak-off pressure could provide a theory basis for safe drilling in high-permeability sandstone formations .
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