为了有效预防和控制裂缝性地层中可能发生的井漏,需要明确钻井液漏失原因,了解钻井液漏失特征及规律,准确预测原地裂缝宽度。借鉴油藏数值模拟和试井的研究思路,通过建立钻井液漏失动力学模型,可以分析井漏的影响因素,反演裂缝宽度,诊断漏失类型,揭示漏失的特征及规律,为防漏堵漏技术研究提供新思路。综述了钻井液漏失动力学模型的研究进展,详细分析了一维径向漏失模型、一维线性漏失模型及二维平面漏失模型的优缺点,阐述了钻井液漏失模型的应用情况,指出耦合井筒压力系统的漏失模型、裂缝网络漏失模型及缝洞型地层漏失模型是今后的主要发展趋势。
Mud loss is a common problem in drilling fractured formations. To prevent and control lost circulation in these kinds of formations, the causes, characteristic and pattern of drilling fluid loss need to be determined,and the width of in-situ fractures needs to be predicted accurately. Using the approach in reservoir simulation and well testing, drilling fluid loss dynamics model can be established to analyze fac- tors causing mud loss, calculate fracture width with inversion, figure out loss type, characteristic and pat- tern, providing a new way for lost circulation prevention and control. This paper summed up the progress in the study on mud loss dynamics model, analyzed the advantages and disadvantages of mud loss models, and introduced the application of the models. At last,it was pointed out that mud loss models considering well- bore pressure, fracture network,mud loss model for fracture-vuggy formations are needed to be developed in the future.