一种基于特征线的溢流预测新方法

A New Method for Overflow Prediction based on Feature Line

为了解决目前国内外在深井钻井过程中溢流风险频发却无法准确预测的问题,考虑立压、出入口流量差、总池体积和全烃4类钻井关键参数,结合4类参数的变化特征趋势,标定了威204H37-1井的溢流变化曲线,提出了一种新的溢流预测方法的特征线数学模型。以中深103井和自213井为具体实例,开展了风险预测分析,与现场实测情况对比,具有高度一致性。结果表明:当溢流发生时,立压变化曲线特征呈缓慢下降趋势;出入口流量差变化曲线特征呈指数上升趋势;总池体积变化曲线特征呈直线上升趋势;全烃变化曲线特征为先下降再上升,符合三角函数变化规律。该方法可通过模型解直观判断出是否发生溢流,既提高了溢流预测精度又缩短了相应时间,能够推动深井和高温高压井风险预警技术的应用与发展。

In order to solve the problem of frequent overflow in deep well drilling at home and abroad which cannot be accurately predicted, considering the four key drilling parameters of vertical pressure, inlet and outlet flow difference,total pool volume and total hydrocarbon, and combining with the variation characteristics of the four parameters, the change curve of Wei 204H37-1 well was demarcated, and a new characteristic line mathematical model of the overflow prediction method was proposed. Taking Zhongshen103 well and Zi213 well as examples, the risk prediction analysis was carried out, the results were highly consistent with the field measurement. The results showed that, when overflow occurred, the vertical pressure variation curve showed a slow downward trend, the inlet and outlet flow difference variation curve showed an exponential upward trend, the total pool volume variation curve showed a straight upward trend, and the total hydrocarbon variation curve showed a decrease first and then rise, according with the change law of trigonometric function. This method can intuitively judge whether overflow occurs through model solution, which can not only improve the prediction accuracy of overflow, but also shorten the corresponding time, and promote the application and development of risk warning technology for deep wells and HPHT wells.