地层测试仪中段塞流的形成原理及应用

Principle and Applications of Slug Flow Formation in Formation Testers

描述地层测试仪中形成段塞流的基本原理和计算油(气)、水分率的方法。适当调整和改进现有增强型地层测试仪(EFDT)工具串,应用于实际地层测试中。分析稠油、凝析气和气体的增强型地层测试仪的现场测试案例。所有的现场地层测试实例说明,在泵抽流体突破泥饼之后,调整后的增强型地层测试仪可获得明显的水—油(气)段塞流,可实时计算出油(气)、水分率,得到某一时间段(例如灌样品瓶时)的油(气)、水占比率。该技术属于中国首创,在没有井下光谱组分仪存在的情况下,通过密度和电导率传感器模块在早期泵抽阶段可知道是否有油气存在,进一步通过密度传感器在早期泵抽阶段判别流体类型,实时计算油(气)、水分率。该创新技术可为井下流体取样提供可靠参数,节约钻井平台时间,降低取样成本和风险。

The basic principle of how to form slug flow in the formation dynamic tester is described in detail,such that the oil(gas)and water fractions can be estimated.The existing enhanced formation dynamic tester(EFDT)tool string is properly adjusted and applied to field test.The EFDT field test cases are analyzed in detail for heavy oil,gas condensate and gas.So far,all the field tests show that after the pumped fluid breaks through the mud cake,the adjusted EFDT can not only obtain the obvious water-oil(gas)slug flow,but also provide the oil(gas)and water fractions in real time,particularly in a certain period of elapse time(for example,during sample bottle filling).This technology is developed for the first time in China.In the absence of downhole optical spectrometers,we can know whether there exists oil or gas,identify the fluid type,and calculate the oil(gas)and water fractions in real time in the early pumping stage through the density and conductivity measurements.This innovative technology can provide reliable parameters for downhole fluid sampling,save rig time,reduce sampling cost and risk.