页岩气体积压裂压后试井分析与评价

发布时间：2018-03-18 23:03

本文选题：体积压裂　切入点：改造体积　出处：《天然气工业》2016年08期 　论文类型：期刊论文

【摘要】：经过体积压裂后的页岩储层,其压后评估和产能预测目前均缺乏相对成熟准确的分析手段,而单一的微地震监测、停泵压降测试等方法在应用上又具有一定的局限性。为此,在充分分析体积压裂所形成的裂缝网络形态和预期改造效果的基础上,采用"较短有效裂缝半长+改造体积内较高的有效渗透率"的方法,对页岩气井体积压裂的改造效果进行分区描述,突出近井地带的主裂缝通道形态,还利用平均有效渗透率概念对中远井地带由复杂、密集的裂缝系统切割破碎的压裂体积的改造效果进行等效描述,解决了传统多长直平面缝模型不能描述改造体积内部拟径向流的问题,更加合理地评价了体积压裂对于改造体积内部渗流能力改善的效果,提高了产能预测的准确性和稳定性。四川盆地威远区块页岩气水平井压裂实践表明:(1)体积压裂所形成网络裂缝的渗流特征与面源缝大不相同,而更近于以射孔孔眼或近井地带一定范围内主裂缝通道为中心点源流动;(2)从试井动态上呈现的是径向或拟径向流特征,而非线性流;(3)利用较短的主裂缝长度和高于页岩基质若干数量级的有效渗透率,可对改造体积进行描述。
[Abstract]:In shale reservoir after volume fracturing, the post-pressure assessment and productivity prediction are lack of relatively mature and accurate analytical means, and the single method of micro-seismic monitoring and pressure drop test of stop pump has some limitations in application. On the basis of fully analyzing the shape of fracture network formed by volume fracturing and the expected effect of revamping, the method of "high effective permeability in short effective fracture and half long reconstruction volume" is adopted. The revamping effect of volume fracturing in shale gas wells is described in different zones, which gives prominence to the main fracture channel form in the near well zone, and makes use of the concept of average effective permeability to complicate the middle and far well zone. The reconstruction effect of fracturing volume is described by the dense fracture system, which solves the problem that the traditional long straight plane fracture model can not describe the pseudo radial flow inside the reconstructed volume. The effect of volume fracturing on the improvement of internal seepage capacity is evaluated more reasonably. The accuracy and stability of productivity prediction are improved. The fracturing practice of shale gas horizontal well in Weiyuan block of Sichuan basin shows that the percolation characteristics of network fractures formed by volume fracturing are quite different from those of non-point source fractures. But it is more similar to the point source flow in a certain range of perforated hole or near well zone.) from the well test performance, it presents radial or quasi-radial flow characteristics. By using the short length of the main fracture and the effective permeability of several orders of magnitude higher than the shale matrix, the revamping volume can be described.
【作者单位】：中国石油长城钻探工程公司四川页岩气项目部;
【分类号】：TE373

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