裂缝型碳酸盐岩油藏试井解释中特殊现象分析

Special phenomena in well test interpretation for fractured carbonate reservoirs

文中针对裂缝型碳酸盐岩试井分析中出现的3种特殊现象进行了探讨。这3种特殊现象为:潮汐效应、油藏压力变化的影响及紊流效应。文中对这3种现象进行了识别,分析了它们产生的原因,并结合实例,分析了对测试数据及解释结果产生的影响。研究发现,潮汐效应对压力恢复早期(前6 h)影响较小,用早期数据作解释比较能真实地反映地层情况;测试期间由周围井生产制度变化引起的油藏压力变化对压力恢复数据有较大影响,解释前需进行校正;紊流效应使原油流入动态关系曲线在测试流量较大时发生明显弯曲。对上述3种现象的识别或校正,减小了非地层因素对测试数据的影响,使试井解释结果更能真实地反映地层参数。

For fractured carbonate reservoirs, three kinds of special phenomena in the well test analysis are discussed in this paper.These three special phenomena are： tidal effect, reservoir pressure change and nonlinear flow. The paper recognized these phenomena and analyzed the occurring reasons and their effects on test data and interpretation results through some cases. The study shows that tidal signal has less effect on the early time of build-up pressure（the first 6 hours）, so the early data interpreting can reflect the property of the formation; during the well test, the reservoir pressure change caused by the production of other wells has a great influence on pressure build-up data, so data correction is needed to remove the influence before interpreting; nonlinear flow causes the inflow performance relation curve of crude oil to bend obviously when the test flow rate is high. The recognition or correction of these three phenomena reduces the non-formation factors′ influence on test data and make the well test interpretation results truly reflect the formation parameters.