基于地层取样的泥浆滤液侵入深度计算新方法

Calculation of Depth of Mud Filtrate Invasion Based on Formation Sampling

刘海波 吴乐军 王猛 张宏伟 秦小飞

LIU Haibo WU Lejun WANG Meng ZHANG Hongwei QIN Xiaofei

中海油田服务股份有限公司油田技术事业部, 河北 燕郊 065201

Well-Tech of China Oilfield Service Limited, Yanjiao, Hebei 065201, China

泥浆滤液侵入深度是测井评价泥浆污染储层程度与准确认识储层评价参数精度的基础参数，传统获得该参数的方法多样，但适用性不够且时效性差。基于地层取样技术，利用泵抽取样过程中时间和电导率曲线的动态关系，可大体把泵抽过程划分为4个阶段，即启动阶段、初始阶段、过渡阶段和稳定阶段，据此可有效确定地层流体突破时间和稳定时间。结合宏观地层模型、储层物性和泵抽参数等因素，建立侵入深度体积模型，实现了定量计算泥浆滤液的侵入深度。分析了地层岩性物性、流体物性、仪器参数和储层污染程度等关键因素对模型计算结果的影响。新方法较传统的数值模拟方法，时效性更高，可靠性更强。该方法在海上数十口探井进行了应用验证，取得了很好的效果，为现场作业决策提供了重要依据。

Depth of mud filtrate invasion is the basic parameter for evaluating mud filtrate-contaminated formation using conventional logging and for understanding the accuracy of reservoir evaluation parameters. There are various traditional methods to obtain this parameter, but they lack applicability and efficiency. Based on the formation sampling technology, the pumping process can be roughly divided into four stages using of the dynamic curve of the conductivity versus time. They are the startup phase, the initial phase, the transition phase and the stable phase. Based on this, the breakthrough time and stabilization time of formation fluid can be effectively determined. Combining factors of macro-stratum model, reservoir physical properties, pumping parameters, the invasion-depth-volume model has been established to quantitatively calculate the depth of mud-filtrate invasion. The influence of key factors such as formation lithology physical properties, fluid physical properties, instrument parameters, reservoir pollution degree on the calculation results is analyzed. In comparison with the traditional numerical simulation method, the new method is more efficient and reliable. This method has been applied to dozens of exploration wells offshore and have been achieved good results, thus providing an important basis for decision-making of field operation.

10.11885/j.issn.1674-5086.2021.08.16.01