电缆取样样品辨析新方法

New Approach to the Discrimination of Samples by Wireline Sampling

在油气田勘探阶段,利用电缆地层测试仪进行取样作业是识别油气水层最直接而有效的重要手段。此文重点论述通过在纯油储层的侵入带地层中灌取泥浆滤液样品,分析化验其滤液氯根浓度,与在同一位置正常取样作业的样品作对比,发现电缆取样作业在纯油层中取到的水都是泥浆滤液,从而总结出需要把样品中水的氯根浓度与钻进到取样深度时所用钻井液的氯根浓度作对比来辨析样品中是否含有地层水这一重要结论。这一结论进一步诠释了如何辨析电缆取样样品,解除了勘探家在纯油层中取到滤液的疑虑,重新使他们对电缆取样作业有了信心。

During the oil and gas exploration, sampling operation with the wireline formation tester（WFT） is the most direct and effective method in identifying oil, gas and water layer correctly. This paper mainly discusses how to distinguish the data of WFT. Comparing the chloride concentration of mud filtrate samples by WFT from the invaded zone or transitional zone of pure oil reservoir with that of samples by conventional sampling operation at the same position, it shows that the water samples obtained by wireline sampling from the pure oil reservoir all are mud filtrate. It is concluded that it is necessary to compare the chloride concentration of water samples with that of drilling fluid used at the same depth in order to distinguish whether the formation water is contained in the samples or not. This conclusion further explains how to distinguish samples by wireline sampling, eliminates the doubts caused by filtrate sampled from the pure oil reservoir, and makes the explorationists＇ regain the confidence in wireline sampling operation.